[{"id":"opp-nectin4-imaging-urothelial","kind":"opportunity","name":"A liver-cleared Nectin-4 tracer for urothelial cancer","aka":["Nectin-4 PET","nectin-4 imaging"],"tldr":"An approved bladder cancer drug works by latching onto a protein called Nectin-4, and half of patients lose that protein as the disease spreads. The one scan built to show it is cleared through the kidneys, so the bladder and the nearby lymph nodes glow with waste tracer and are the hardest places to read.","summary":"Enfortumab vedotin, a Nectin-4-directed antibody-drug conjugate, has been approved since December 2019 and now reaches into the perioperative setting: in November 2025 the FDA approved pembrolizumab with enfortumab vedotin as neoadjuvant then adjuvant treatment for cisplatin-ineligible muscle-invasive bladder cancer, on a trial of 344 patients that reported a hazard ratio of 0.40 for recurrence, progression or death. Selection does not require a Nectin-4 assay, yet Nectin-4 expression falls in more than half of cases during metastatic progression and more than a third of metastases are Nectin-4-negative.\n\nThe imaging work is almost entirely Chinese and academic. The bicyclic peptide tracer 68Ga-N188, from Peking University, has a published first-in-human study in 14 patients with advanced urothelial cancer plus two healthy volunteers, and a 62-patient head-to-head study against FDG across 16 tumour types. It is registered in three Chinese trials. Its published limitation is decisive for the indication that matters most: the tracer is excreted in urine, and a 2025 review states plainly that this poses challenges for in-situ bladder cancer detection because of high background activity in the urinary tract.\n\nSo the opportunity is not a target in search of a tracer, nor a tracer in search of a target, but a pharmacokinetic specification: a Nectin-4 ligand cleared hepatobiliary rather than renally, which could read the bladder wall and the pelvic nodes where staging and surgical decisions are actually made.","asOf":"2026-09-23","links":[{"label":"68Ga-N188 first-in-human, Clinical Cancer Research 2023","url":"https://pubmed.ncbi.nlm.nih.gov/37093191/"},{"label":"68Ga-N188 against FDG in 62 patients, Journal of Nuclear Medicine 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38719240/"},{"label":"Review noting urinary excretion as a barrier to in-situ bladder detection, 2025","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12227459/"},{"label":"Nectin-4 expression and loss in metastatic progression, Clinical Cancer Research 2023","url":"https://aacrjournals.org/clincancerres/article/29/8/1496/725070/Membranous-NECTIN-4-Expression-Frequently"},{"label":"FDA: perioperative enfortumab vedotin plus pembrolizumab, November 2025","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pembrolizumab-enfortumab-vedotin-ejfv-muscle-invasive-bladder-cancer"}],"tags":["theranostic gap","bladder","clearance","pelvic staging"],"related":["ga-68","f-18"],"indications":["urothelial-cancer"],"sections":[],"technologies":["pet-ct","peptide-drug-conjugate"],"targets":["nectin4"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"theranostic-gap","unmetNeed":"Before radical cystectomy or before starting enfortumab vedotin, no test shows whether the bladder tumour and the pelvic nodes still express Nectin-4, because the only human Nectin-4 tracer is renally excreted and urinary activity obscures exactly that region.","useCase":"A urologist and a nuclear medicine physician would use it twice: to stage the pelvis before cystectomy, where CT nodal staging is weak, and to confirm target expression across metastatic sites before committing a patient to an antibody-drug conjugate with a real toxicity burden. A hepatobiliary-cleared tracer would make the bladder wall and pelvic nodes readable on the same scan.","hypothesis":"A Nectin-4-binding peptide or small molecule engineered for hepatobiliary clearance will image the primary bladder tumour and pelvic nodes that the renally excreted 68Ga-N188 cannot, and will detect the loss of Nectin-4 in metastatic disease that a single biopsy misses.","rationale":"Nectin-4 is expressed in 83 to 97% of bladder cancers depending on the series and antibody used, and 68Ga-N188 has already shown that the target is reachable with a bicyclic peptide in humans. Loss of expression during metastatic progression is documented in more than half of cases, with over a third of metastases negative, and NECTIN4 amplification has been proposed as a more stable predictor of enfortumab vedotin benefit than protein staining. The failure mode of the existing tracer is excretion route, not affinity, and clearance can be engineered: the same problem was solved for other peptide classes by changing linker charge and lipophilicity.","test":"A first-in-human study of a hepatobiliary-cleared Nectin-4 ligand in patients scheduled for radical cystectomy with pelvic lymph node dissection, with node-by-node histopathology as the truth standard, reporting sensitivity and specificity for pelvic nodal metastasis and, as a co-primary, the readability of the bladder wall against the published renally excreted comparator.","maturity":"early-clinical","verdict":"standalone-and-companion","mostAdvanced":"68Ga-N188, a bicyclic peptide tracer from Peking University Cancer Hospital, with two published human studies (14 patients, then 62 across 16 tumour types) and three registered Chinese trials, but renal excretion that limits pelvic reading.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"Nectin-4 is reported in 83% of 524 bladder cancers by tissue microarray and over 97% in another series, against 67% in upper-tract disease; expression falls in more than 50% of cases during metastatic progression, with over a third of metastases negative.","source":"Klumper et al., Clinical Cancer Research 2023; Hoffman-Censits review","url":"https://aacrjournals.org/clincancerres/article/29/8/1496/725070/Membranous-NECTIN-4-Expression-Frequently","weighted":true},{"domain":"clinical-evidence","state":"moderate","why":"68Ga-N188 has a published first-in-human study of 14 patients with advanced urothelial cancer and a 62-patient head-to-head study against FDG, all single-country and academic.","source":"Duan et al., Clinical Cancer Research 2023; Zhang et al., J Nucl Med 2024","url":"https://pubmed.ncbi.nlm.nih.gov/37093191/"},{"domain":"diagnostic-performance","state":"thin","why":"No study reports sensitivity or specificity against nodal histopathology, and the published review states that urinary excretion challenges in-situ bladder detection because of urinary-tract background.","source":"Speltri, Badrane et al., Molecular Diagnosis and Therapy 2025","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12227459/","weighted":true},{"domain":"safety-dosimetry","state":"thin","why":"No adverse events are reported in the published first-in-human cohorts, but the series are small and no formal dosimetry figure for a pelvis-readable construct exists because no such construct has been made.","source":"Duan et al., Clinical Cancer Research 2023","url":"https://pubmed.ncbi.nlm.nih.gov/37093191/"},{"domain":"regulatory-path","state":"moderate","why":"No Nectin-4 imaging agent has any filing anywhere, but 68Ga-PSMA-11 set the precedent for a pelvic-nodal claim: its initial-staging trial used sensitivity and specificity for pelvic nodal metastases against prostatectomy pathology as the primary endpoint.","source":"FDA multidiscipline review, 68Ga-PSMA-11","url":"https://jnm.snmjournals.org/content/62/2/146"}],"flags":[{"category":"technical","flag":"red","why":"The known human tracer is renally excreted and its own literature says this obstructs in-situ bladder detection; the opportunity requires re-engineering clearance, which is unproven for this ligand class."},{"category":"unmet-need","flag":"green","why":"Nodal staging before cystectomy is weak on CT and target loss in metastatic disease is documented in over half of cases, so both the staging and the selection question are live."},{"category":"ip","flag":"amber","why":"The bicyclic peptide scaffold behind 68Ga-N188 derives from a therapeutic programme, and the leading published work sits with Chinese academic centres; freedom to operate for a new clearance-engineered ligand is unexamined in public sources."},{"category":"commercial","flag":"green","why":"A pelvis-readable tracer has a staging use of its own in muscle-invasive disease as well as a selection use alongside an approved antibody-drug conjugate now moving into perioperative treatment."},{"category":"isotope","flag":"green","why":"Gallium-68 already works for the peptide, and a fluorine-18 version would suit distribution."},{"category":"competition","flag":"amber","why":"Three registered Chinese trials of 68Ga-N188 are running and the field is publishing quickly, but nobody has disclosed a hepatobiliary-cleared construct."}],"competition":[{"name":"Peking University Cancer Hospital and Peking University First Hospital","what":"68Ga-N188, the only Nectin-4 tracer with published human data; three registered trials (NCT05321316, NCT05593107, NCT06648317).","stage":"early clinical","url":"https://pubmed.ncbi.nlm.nih.gov/37093191/"},{"name":"Astellas and Pfizer","what":"Enfortumab vedotin, the approved Nectin-4 antibody-drug conjugate that creates the selection question; no Nectin-4 assay is required on the label.","stage":"approved","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pembrolizumab-enfortumab-vedotin-ejfv-muscle-invasive-bladder-cancer"},{"name":"Mayo Clinic Laboratories","what":"A commercially available Nectin-4 immunohistochemistry assay reporting percent positive cells and H-score, the incumbent test.","stage":"in clinical use","url":"https://www.mayocliniclabs.com/test-catalog/Overview/622259"}],"differentiation":"Nectin-4 immunohistochemistry is already purchasable and NECTIN4 amplification by FISH has been proposed as a more stable predictor of benefit. Both need a biopsy of one lesion. No blood or ctDNA test for Nectin-4 status was found. Imaging earns its place only where the answer differs between lesions, or where the lesion in question is a pelvic node nobody wants to biopsy.","metrics":[{"label":"Bladder cancers positive for Nectin-4 by tissue microarray","value":"83% of 524","source":"Challita-Eid et al., cited in Hoffman-Censits review","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8429050/"},{"label":"Cases losing Nectin-4 expression during metastatic progression","value":"over 50%","source":"Klumper et al., Clinical Cancer Research 2023","url":"https://aacrjournals.org/clincancerres/article/29/8/1496/725070/Membranous-NECTIN-4-Expression-Frequently"},{"label":"Reduction in risk of recurrence, progression or death with perioperative enfortumab vedotin plus pembrolizumab","value":"HR 0.40","source":"EV-303/KEYNOTE-905, 344 patients, FDA approval November 2025","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pembrolizumab-enfortumab-vedotin-ejfv-muscle-invasive-bladder-cancer"}],"risks":["Clearance engineering may not survive contact with affinity: a hepatobiliary-cleared analogue could lose the binding that makes the peptide work.","Hepatic background could simply move the problem, since the liver is a common site of urothelial metastasis.","If NECTIN4 amplification on tissue turns out to predict benefit reliably, the selection half of the case weakens and only the staging use remains."],"watch":["Results from the three registered 68Ga-N188 trials, particularly any per-lesion comparison against nodal pathology.","Any published Nectin-4 ligand with a hepatobiliary clearance profile, which would be the first direct competitor for this specification.","Whether the perioperative approval shifts practice toward pre-cystectomy target confirmation, which is where a readable pelvis pays."]},{"id":"opp-alpha-synuclein-pet-parkinsons","kind":"opportunity","name":"Alpha-synuclein PET: works for MSA, not for Parkinson's","aka":["a-synuclein PET","ACI-12589"],"tldr":"Parkinson's disease is defined by a protein clumping in the brain, and no scan can see it. The first tracer to reach patients does light up a rarer, related disease but not Parkinson's itself, while a spinal-fluid test already identifies Parkinson's with high accuracy.","summary":"Amyloid and tau both have approved PET agents. Alpha-synuclein, the protein that defines Parkinson's disease, dementia with Lewy bodies and multiple system atrophy, has none: no small molecule targeting misfolded alpha-synuclein has been approved by the FDA as a PET radiopharmaceutical. The clinical consequence is that early Parkinson's cannot be separated from multiple system atrophy or progressive supranuclear palsy when the picture is ambiguous, and no anti-alpha-synuclein drug programme can show target engagement in a living brain.\n\nThe most advanced agent is [18F]ACI-12589 from AC Immune, with a 42-participant published dataset in Nature Communications in 2023: 8 healthy controls, 8 Parkinson's, 2 dementia with Lewy bodies, 13 multiple system atrophy, 3 progressive supranuclear palsy, 5 Alzheimer's and 3 hereditary ataxias. The result is a genuine partial success and a genuine partial failure. Binding statistically separated multiple system atrophy patients from controls and from other neurodegenerative disorders, with clear signal in cerebellar white matter and middle cerebellar peduncles, but limited binding in Parkinson's disease; a conference report put it more bluntly, that PET signals were undetectable in other synucleinopathies despite the tracer binding post-mortem tissue from those same disorders.\n\nMeanwhile the non-imaging competitor has already won the diagnostic question for Parkinson's. Seed amplification assays on cerebrospinal fluid are reported at 87.7% sensitivity and 96.3% specificity for Parkinson's in the PPMI cohort, with a pooled meta-analysis at 0.86 and 0.92. What the assay cannot do is say where in the brain the pathology is, or how much, or whether a drug reduced it, and it is markedly less reliable in multiple system atrophy. That is the residual space an imaging agent has.","asOf":"2026-09-23","links":[{"label":"[18F]ACI-12589 first-in-human, Nature Communications 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10611796/"},{"label":"Conference report: signal only in multiple system atrophy","url":"https://www.alzforum.org/news/conference-coverage/first-field-synuclein-pet-only-multiple-system-atrophy"},{"label":"No approved small-molecule alpha-synuclein PET agent","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC13121216/"},{"label":"Seed amplification assays: past, present and future roles","url":"https://www.movementdisorders.org/MDS/Scientific-Issues/posts/The-past-present-and-future-roles-of-a-synuclein-seed-amplification-assays.htm"},{"label":"Pooled meta-analysis of alpha-synuclein seed amplification assays","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12192484/"}],"tags":["unmet need first","neurology","worked negative","pharmacodynamic marker"],"related":["f-18","tau-protein","amyloid-beta"],"indications":["parkinsonian-syndromes"],"sections":[],"technologies":["pet","pet-ct"],"targets":["alpha-synuclein","dopamine-transporter"],"drugs":["i-123-ioflupane"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"unmet-need-first","unmetNeed":"There is no way to see pathological alpha-synuclein in a living brain, so ambiguous parkinsonian syndromes cannot be told apart at the molecular level and no anti-alpha-synuclein drug can demonstrate that it engaged its target.","useCase":"The credible use today is inside drug development: measuring regional target load and its change on treatment in an anti-alpha-synuclein trial, and enriching multiple system atrophy cohorts. A clinical differential-diagnosis use would require sensitivity in Parkinson's disease that the leading tracer does not yet have.","hypothesis":"A next-generation alpha-synuclein tracer with higher affinity for Lewy-type aggregates will detect the lower-density, more diffuse pathology of Parkinson's disease that [18F]ACI-12589 misses, and will thereby provide the regional quantification that a cerebrospinal fluid assay cannot.","rationale":"The target is the defining pathology of a large disease group, and the precedent is exact: amyloid and tau agents were approved on the basis of visual and quantitative correspondence with post-mortem pathology, which is the same claim structure an alpha-synuclein agent would make. The first-generation tracer proves the concept is reachable, because it does separate multiple system atrophy from controls. Against that, its failure in Parkinson's is the central obstacle, and it appears to be a density and affinity problem rather than a specificity one, since the same tracer binds Parkinson's tissue post mortem.","test":"A head-to-head study in patients with a positive cerebrospinal fluid seed amplification assay, comparing a next-generation tracer's regional binding against the assay result and against clinical diagnosis, powered to detect Parkinson's disease against controls. The tracer must clear the bar that the current agent failed: a measurable signal in Parkinson's, not only in multiple system atrophy.","maturity":"early-clinical","verdict":"companion-only","mostAdvanced":"[18F]ACI-12589 (also [18F]MNI-1216) from AC Immune, first-in-human complete under NCT06445465 with a 42-participant validation cohort published in Nature Communications 2023; it separates multiple system atrophy from controls but shows limited binding in Parkinson's disease.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"Alpha-synuclein aggregation defines Parkinson's disease, dementia with Lewy bodies and multiple system atrophy, and the tracer binds post-mortem tissue from all of them; the in-vivo failure is one of aggregate density, not of target validity.","source":"Nature Communications 2023 and Alzforum conference report","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10611796/","weighted":true},{"domain":"clinical-evidence","state":"thin","why":"One published 42-participant cohort from one tracer, plus a completed phase 1; no agent has reached a pivotal or registrational trial and no FDA-approved alpha-synuclein PET agent exists.","source":"Nature Communications 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10611796/"},{"domain":"diagnostic-performance","state":"thin","why":"Binding separates multiple system atrophy from controls and from other neurodegenerative disorders, but is limited in Parkinson's disease, which is the population that would generate most of the demand.","source":"Nature Communications 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10611796/","weighted":true},{"domain":"safety-dosimetry","state":"thin","why":"No serious safety signal has been reported in the small published cohorts, but no independently verified dosimetry table for the leading agent was found."},{"domain":"regulatory-path","state":"moderate","why":"A precedent exists for approving an intracellular-aggregate PET agent: flortaucipir F-18 and the amyloid agents were approved on correspondence with pathology rather than on a treatment-selection claim.","source":"FDA label, flortaucipir F-18","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/212123s000lbl.pdf"}],"flags":[{"category":"technical","flag":"red","why":"The leading fluorine-18 tracer gives no detectable signal in Parkinson's disease in vivo despite binding the tissue post mortem; that is the whole technical problem and it is unsolved."},{"category":"unmet-need","flag":"amber","why":"The diagnostic need is real but partly met: a cerebrospinal fluid assay reaches 87.7% sensitivity and 96.3% specificity for Parkinson's, leaving imaging the regional and pharmacodynamic questions."},{"category":"ip","flag":"amber","why":"The leading chemical series belongs to AC Immune; several academic and company programmes are chasing new scaffolds."},{"category":"commercial","flag":"red","why":"Companion-only in practice, and no anti-alpha-synuclein therapy is approved; prasinezumab did not separate from placebo on the primary endpoint of its phase 2."},{"category":"isotope","flag":"green","why":"Fluorine-18, the most distributable PET isotope."},{"category":"competition","flag":"amber","why":"Several groups are pursuing new scaffolds and the cerebrospinal fluid assay is already in wide research use, so a tracer must beat a cheap incumbent on a narrower question."}],"competition":[{"name":"AC Immune SA with Invicro","what":"[18F]ACI-12589 / [18F]MNI-1216, first-in-human complete, 42-participant published cohort; works in multiple system atrophy, limited in Parkinson's.","stage":"phase 1 complete","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10611796/"},{"name":"Seed amplification assay developers","what":"Cerebrospinal fluid alpha-synuclein seed amplification, reported at 87.7% sensitivity and 96.3% specificity for Parkinson's in the PPMI cohort.","stage":"in research and clinical use","url":"https://www.movementdisorders.org/MDS/Scientific-Issues/posts/The-past-present-and-future-roles-of-a-synuclein-seed-amplification-assays.htm"}],"differentiation":"A seed amplification assay answers whether seed-competent alpha-synuclein is present anywhere, cheaply and with high accuracy in Parkinson's; it does not localise, quantify, or track change, and is markedly less reliable in multiple system atrophy. An imaging agent that only matched the assay's diagnostic accuracy would not be worth its cost; one that measured regional load and its change on treatment would be.","metrics":[{"label":"Participants in the published [18F]ACI-12589 in-vivo cohort","value":"42, including 13 with multiple system atrophy and 8 with Parkinson's","source":"Nature Communications 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10611796/"},{"label":"Cerebrospinal fluid seed amplification assay accuracy for Parkinson's in the PPMI cohort","value":"87.7% sensitivity, 96.3% specificity","source":"Reported from the PPMI Lancet Neurology analysis","url":"https://www.movementdisorders.org/MDS/Scientific-Issues/posts/The-past-present-and-future-roles-of-a-synuclein-seed-amplification-assays.htm"},{"label":"Pooled seed amplification assay sensitivity and specificity across biomatrices","value":"0.86 and 0.92","source":"Pooled meta-analysis","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12192484/"}],"risks":["Lewy-type aggregate density in Parkinson's disease may simply be below what PET can resolve, in which case no affinity improvement rescues the indication.","Without an approved anti-alpha-synuclein therapy there is no companion market, and the leading antibody missed its phase 2 primary endpoint.","The cerebrospinal fluid assay is cheap, accurate for Parkinson's and already adopted in research, which caps what an imaging agent can claim."],"watch":["Any tracer reporting a measurable Parkinson's-versus-control difference in vivo, which is the single result that would change this record.","Longitudinal multiple system atrophy studies with the current agent, which could establish a progression biomarker even without a Parkinson's claim.","Anti-alpha-synuclein therapeutic readouts, since a companion agent needs a drug to accompany."]},{"id":"opp-cardiac-sarcoidosis-specific-tracer","kind":"opportunity","name":"An inflammation tracer that does not need a diet","aka":["SSTR PET in cardiac sarcoidosis"],"tldr":"Deciding whether to put a patient on long-term steroids for heart sarcoidosis depends on a scan that only works if the patient's heart has been starved of sugar for a day, and a biopsy that misses the disease most of the time. A different tracer would not need the diet.","summary":"Cardiac sarcoidosis is the case where the incumbent test's weakness is procedural rather than biological. FDG PET requires metabolic suppression of normal myocardium through a strict low-carbohydrate, high-fat preparation, and imperfect suppression produces false positives on which immunosuppression decisions are then made. The histological reference standard is worse: endomyocardial biopsy sensitivity is reported at approximately 20 to 30%, and elsewhere as less than 25%. There is no reliable serum biomarker for diagnosis, monitoring of inflammatory activity or severity. And the disease is substantially under-recognised: about 5% of sarcoidosis patients have clinically manifest cardiac involvement while autopsy series report 25% to 50%.\n\nSomatostatin receptor tracers are the most developed alternative because macrophages in active granulomas express SSTR2, and no dietary preparation is needed. The evidence is consistent but small and mixed. A University of Pennsylvania study of 11 patients found 91% patient-level concordance with FDG but only 77.1% segment-level agreement, a lower signal-to-blood-pool ratio of 3.2 against 4.9, and underestimation of treatment response. A Würzburg 68Ga-DOTATOC study of 15 patients found SSTR-PET positive in 7 of 15 against cardiac MRI in 10 of 15. A 19-patient comparative study of 68Ga-DOTANOC has been reported at 100% diagnostic accuracy against 79% for FDG, while a 17-patient study found poorer agreement with MRI at 76.5%.\n\nThe practical attraction is that the tracer itself is already approved for another indication as NETSPOT, so manufacturing and dosimetry are de-risked; what is missing is a clinical package for this indication, and a completed 78-patient Swedish study with biopsy and MRI comparators is the largest dataset that could supply one.","asOf":"2026-09-23","links":[{"label":"68Ga-DOTATATE against FDG in cardiac sarcoidosis, J Nucl Cardiol 2023","url":"https://link.springer.com/article/10.1007/s12350-022-03111-4"},{"label":"NCT04206163: somatostatin receptor imaging in inflammatory heart disease, 78 patients","url":"https://clinicaltrials.gov/study/NCT04206163"},{"label":"No reliable serum biomarker in sarcoidosis, JACC state-of-the-art review","url":"https://www.jacc.org/doi/10.1016/j.jacc.2020.08.042"},{"label":"Clinically manifest against autopsy prevalence, JAHA 2023","url":"https://www.ahajournals.org/doi/10.1161/JAHA.122.028342"},{"label":"68Ga-DOTATOC compared with cardiac MRI, Oncotarget 2016","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5363622/"}],"tags":["unmet need first","cardiac","non-oncology","inflammation"],"related":["ga-68","f-18"],"indications":["cardiac-sarcoidosis"],"sections":[],"technologies":["sstr-pet","fdg-pet","pet-ct"],"targets":["sstr2"],"drugs":["ga68-dotatate","fludeoxyglucose-f18","ga-68-dotatoc"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"unmet-need-first","unmetNeed":"No non-invasive test reliably establishes whether myocardial inflammation is active right now, because FDG PET depends on imperfect dietary suppression, endomyocardial biopsy has sensitivity of roughly 20 to 30%, and no serum biomarker exists.","useCase":"A cardiologist would use it to decide whether to start or continue immunosuppression in suspected cardiac sarcoidosis, and to judge response on treatment, in the specific patients where FDG preparation has failed or is impractical, such as those with diabetes.","hypothesis":"A somatostatin-receptor or other macrophage-directed tracer will identify active cardiac sarcoidosis with accuracy at least equal to well-prepared FDG PET while removing the dietary preparation, and will therefore give a reliable answer in the patients where FDG currently fails.","rationale":"Activated macrophages in sarcoid granulomas express somatostatin receptor 2, so there is a specific target for active inflammation rather than a metabolic surrogate. The tracer is already manufactured and approved for neuroendocrine tumour imaging, which removes most chemistry and dosimetry risk. Five independent cohorts have imaged cardiac sarcoidosis patients with SSTR agents and all reported detectable disease. Against that, the Pennsylvania study found a lower signal-to-background ratio than FDG and underestimation of treatment response, and the segment-level agreement of 77.1% is not good enough to guide focal management.","test":"A prospective multicentre study in suspected cardiac sarcoidosis, imaging every patient with both an SSTR tracer and correctly prepared FDG PET, with cardiac MRI and where available endomyocardial biopsy as comparators, and a pre-specified analysis of the subgroup in which FDG suppression failed. The endpoint that matters is agreement with the final adjudicated diagnosis and with treatment response, not agreement with FDG.","maturity":"early-clinical","verdict":"standalone-only","mostAdvanced":"68Ga-DOTATATE and related SSTR ligands used off-label in completed academic studies: 11 patients at the University of Pennsylvania (NCT03746847), 15 at Mayo Clinic (NCT03549598) and 78 in a completed Swedish study of inflammatory heart disease (NCT04206163). No agent is near filing for this indication.","dueDiligence":[{"domain":"target-biology","state":"moderate","why":"Activated macrophages in sarcoid granulomas express somatostatin receptor 2, giving a specific inflammation target, but signal-to-blood-pool ratio was lower than FDG at 3.2 plus or minus 0.6 against 4.9 plus or minus 1.5.","source":"Lee et al., J Nucl Cardiol 2023","url":"https://link.springer.com/article/10.1007/s12350-022-03111-4","weighted":true},{"domain":"clinical-evidence","state":"thin","why":"Five small cohorts, the largest a completed 78-patient Swedish study that also enrolled myocarditis; the published cardiac sarcoidosis series are 11, 15, 17 and 19 patients.","source":"NCT04206163","url":"https://clinicaltrials.gov/study/NCT04206163"},{"domain":"diagnostic-performance","state":"moderate","why":"Patient-level concordance with FDG was 91% but segment-level agreement only 77.1% with kappa 0.53; one 19-patient study reported 100% accuracy against 79% for FDG, while a 17-patient study found only 76.5% agreement with MRI.","source":"Lee et al. 2023 and comparative reviews","url":"https://ajronline.org/doi/10.2214/AJR.20.22790","weighted":true},{"domain":"safety-dosimetry","state":"strong","why":"The tracer is approved as NETSPOT for neuroendocrine tumour localisation, so its manufacturing, safety and dosimetry package already exists; only the cardiac indication is off-label.","source":"FDA label, NETSPOT","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/208547s024lbl.pdf"},{"domain":"regulatory-path","state":"thin","why":"No SSTR agent has a cardiac sarcoidosis indication and none has filed for one; the route would be a new indication on an approved molecule, judged against FDG PET and adjudicated diagnosis.","source":"FDA label, NETSPOT","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/208547s024lbl.pdf"}],"flags":[{"category":"technical","flag":"amber","why":"No dietary preparation is the whole point, but the published signal-to-blood-pool ratio is lower than FDG and treatment response was underestimated in the largest concordance study."},{"category":"unmet-need","flag":"green","why":"An immunosuppression decision currently rests on a diet-dependent scan and a biopsy with roughly 20 to 30% sensitivity, with no serum biomarker of any kind."},{"category":"ip","flag":"red","why":"The leading agents are approved generic-era somatostatin ligands; there is no proprietary position to take in DOTATATE itself."},{"category":"commercial","flag":"amber","why":"Standalone and repeatable for treatment monitoring, but cardiac sarcoidosis is a small indication and the tracer is already purchasable for another one, so a sponsor would fund a trial for a label it may not be able to protect."},{"category":"isotope","flag":"green","why":"Gallium-68 from a generator, already distributed for neuroendocrine imaging."},{"category":"competition","flag":"amber","why":"The competition is off-label use of an approved tracer, which is cheap and available now and therefore hard to displace with a funded programme."}],"competition":[{"name":"University of Pennsylvania","what":"68Ga-DOTATATE against FDG in 11 cardiac sarcoidosis patients with follow-up scans in 8; 91% patient-level concordance, 77.1% segment-level.","stage":"completed pilot","url":"https://link.springer.com/article/10.1007/s12350-022-03111-4"},{"name":"Mayo Clinic","what":"Phase 4 comparison of 68Ga-DOTATATE with FDG and 13N-ammonia PET/CT, 15 patients, completed.","stage":"completed","url":"https://clinicaltrials.gov/study/NCT03549598"},{"name":"Västra Götaland Region, Sweden","what":"68Ga-DOTA-TOC in inflammatory heart disease, 78 participants, against contrast MRI, FDG PET and endomyocardial biopsy; completed June 2024.","stage":"completed","url":"https://clinicaltrials.gov/study/NCT04206163"},{"name":"Würzburg and other academic groups","what":"68Ga-DOTATOC in 15 patients with biopsy-proven sarcoidosis and suspected cardiac involvement, positive in 7 of 15 against MRI in 10 of 15.","stage":"published feasibility","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5363622/"}],"differentiation":"There is presently no reliable serum biomarker for diagnosis, monitoring of inflammatory activity or severity in sarcoidosis, and cardiac MRI shows scar rather than current activity. The differentiation from FDG is entirely operational: no dietary preparation, and therefore an answer in patients whose suppression fails, including those with diabetes.","metrics":[{"label":"Patient-level and segment-level concordance of 68Ga-DOTATATE with FDG","value":"91% and 77.1% in 11 patients","source":"Lee et al., J Nucl Cardiol 2023","url":"https://link.springer.com/article/10.1007/s12350-022-03111-4"},{"label":"Endomyocardial biopsy sensitivity for cardiac sarcoidosis","value":"approximately 20 to 30%","source":"Published review","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8746035/"},{"label":"Clinically manifest against autopsy prevalence of cardiac involvement in sarcoidosis","value":"about 5% against 25 to 50%","source":"Sperry et al., JAHA 2023","url":"https://www.ahajournals.org/doi/10.1161/JAHA.122.028342"}],"risks":["The lower signal-to-blood-pool ratio and underestimated treatment response reported at Pennsylvania could make the agent worse than a well-prepared FDG scan rather than better.","Segment-level agreement of 77.1% is not adequate for guiding focal decisions such as device placement or ablation.","Because the tracer is already on the market for another indication, off-label use will absorb the clinical demand and nobody may fund the registrational study."],"watch":["Publication of the 78-patient Swedish study, which is the largest dataset and includes biopsy comparison.","Any macrophage-directed tracer with a better signal-to-background ratio than the somatostatin ligands, which is the specific weakness to beat.","Guideline language on alternatives to FDG when metabolic suppression fails, which would create the indication a sponsor could file against."]},{"id":"opp-caix-indeterminate-renal-mass","kind":"opportunity","name":"CAIX imaging of the indeterminate renal mass","aka":["CA9 imaging","girentuximab PET"],"tldr":"Scans find small kidney lumps all the time and cannot tell which are cancer. Up to one in five that are surgically removed turn out to be harmless. A scan that recognises the commonest kidney cancer would spare those operations, and it needs no drug to be useful.","summary":"This is the cleanest standalone diagnostic case in the field: the scan answers a question on its own, with no therapy dependency. Between 12.8% and 40% of surgically resected small renal masses are benign depending on size, and no imaging technique reliably defines histological subtype before surgery.\n\nThe lead agent has the evidence. 89Zr-girentuximab (TLX250-CDx, Zircaix) reported phase 3 ZIRCON results in Lancet Oncology in October 2024: 300 patients dosed, 284 evaluable, sensitivity 85.5% and specificity 87.0% for clear cell renal cell carcinoma, with no safety signals. The BLA was accepted with priority review and a PDUFA date of 27 August 2025, but the FDA issued a complete response letter on chemistry, manufacturing and controls rather than efficacy or safety; the sponsor has since reported agreement on remediation after Type A meetings. It remains unapproved anywhere.\n\nBehind it sit peptide and small-molecule CAIX ligands with same-day kinetics: 68Ga-DPI-4452 has FDA Fast Track designation and first-in-human data, and a technetium-99m CAIX peptide and a gallium-68 CAIX agent have small first-in-human cohorts. Chinese academic work includes a 47-patient 68Ga-NY104 cohort. The opportunity split is therefore sharp: the antibody owns the evidence and the regulatory queue, while the unmet need for a same-day, widely distributable agent is unmet by definition because no peptide has a phase 3.","asOf":"2026-09-23","links":[{"label":"ZIRCON phase 3, Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/"},{"label":"NCT03849118: ZIRCON","url":"https://clinicaltrials.gov/study/NCT03849118"},{"label":"Girentuximab dosimetry","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8426244/"},{"label":"Benign proportion of resected small renal masses","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2797464/"}],"tags":["standalone diagnostic","kidney","biopsy avoidance"],"related":["zr-89","ga-68","tc-99m"],"indications":["rcc"],"sections":[],"technologies":["caix-pet","immuno-pet","pet-ct"],"targets":["caix"],"drugs":["girentuximab-zr89","itm-11"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"standalone-diagnostic","unmetNeed":"When CT or MRI finds an indeterminate renal mass, nothing tells the clinician whether it is clear cell renal cell carcinoma before committing the patient to surgery, biopsy or surveillance, and up to a fifth of resected small masses prove benign.","useCase":"A urologist would order it for the indeterminate small renal mass, to separate clear cell carcinoma from benign or non-clear-cell lesions before deciding between surgery, ablation and surveillance; and in metastatic disease to characterise lesions of uncertain origin. It requires no drug approval to be worth doing, which is what makes it a standalone opportunity.","hypothesis":"A same-day CAIX ligand will reach the diagnostic accuracy that the antibody achieved in ZIRCON while allowing imaging within hours of injection, making the test deliverable in a routine urology pathway rather than requiring a return visit days later.","rationale":"CAIX is expressed in over 90% of clear cell renal cell carcinomas because VHL loss leaves the HIF pathway constitutively active, and essentially absent in normal kidney, which is why the antibody reached 85.5% sensitivity and 87.0% specificity in a 284-patient phase 3. The antibody's limitation is kinetic, not biological: a full antibody labelled with zirconium-89 requires imaging days after injection. Peptide and small-molecule ligands have already shown human uptake, and the precedent from other target classes is that the small-molecule generation displaces the antibody once accuracy is matched.","test":"A prospective multicentre study of a same-day CAIX ligand in patients with an indeterminate renal mass scheduled for resection or biopsy, with histopathology as the truth standard, powered for sensitivity and specificity against the ZIRCON benchmark of 85.5% and 87.0%, and reporting the proportion of planned operations avoided.","maturity":"being-tested-at-scale","verdict":"standalone-only","mostAdvanced":"89Zr-girentuximab (TLX250-CDx, Telix), phase 3 ZIRCON published in Lancet Oncology 2024, BLA accepted with priority review but issued a complete response letter on manufacturing in August 2025 and unapproved anywhere.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"CAIX is expressed in over 90% of clear cell renal cell carcinoma through constitutive HIF-1 activity after VHL loss, and is essentially absent from normal renal parenchyma.","source":"Nuclide CAIX target record and the ZIRCON literature","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/"},{"domain":"clinical-evidence","state":"strong","why":"A completed phase 3 of 300 dosed and 284 evaluable patients published in Lancet Oncology, the only phase 3 diagnostic dataset for any CAIX agent.","source":"ZIRCON, Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/","weighted":true},{"domain":"diagnostic-performance","state":"strong","why":"Sensitivity 85.5% (95% CI 81.5 to 89.6) and specificity 87.0% (81.0 to 93.1) for clear cell renal cell carcinoma in ZIRCON.","source":"ZIRCON, Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/","weighted":true},{"domain":"safety-dosimetry","state":"strong","why":"No safety signals in the phase 3; girentuximab whole-body effective dose is reported at 0.57 plus or minus 0.08 mSv/MBq.","source":"ZIRCON and published dosimetry","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8426244/"},{"domain":"regulatory-path","state":"moderate","why":"The pathway is proven to the point of a priority-review BLA, then blocked: the FDA issued a complete response letter on chemistry, manufacturing and controls, not on efficacy or safety, and the product is approved nowhere.","source":"Sponsor and partner disclosures","url":"https://heidelberg-pharma.com/en/research-development/other-projects"}],"flags":[{"category":"technical","flag":"amber","why":"The proven agent is a zirconium-89 antibody imaged days after injection; the same-day peptides have small cohorts and no accuracy dataset."},{"category":"unmet-need","flag":"green","why":"Up to 15 to 20% of resected small renal masses are benign and no imaging test defines subtype, so the scan prevents operations rather than selecting drugs."},{"category":"ip","flag":"red","why":"The antibody and its phase 3 dataset are owned, and several peptide and small-molecule CAIX ligands are already claimed by companies with first-in-human data; entering now means designing around a crowded space."},{"category":"commercial","flag":"green","why":"Standalone by construction: reimbursement rests on avoided surgery, not on another company's drug approval, which is the strongest commercial position a diagnostic can have."},{"category":"isotope","flag":"amber","why":"Zirconium-89 is cyclotron-made with limited distribution; a gallium-68 or fluorine-18 ligand would remove that constraint."},{"category":"competition","flag":"red","why":"A phase 3 agent sits in the regulatory queue and at least three peptide or small-molecule programmes have human data, so the field is contested at every stage."}],"competition":[{"name":"Telix Pharmaceuticals","what":"89Zr-girentuximab (TLX250-CDx, Zircaix): phase 3 ZIRCON published, BLA accepted with priority review, complete response letter on manufacturing August 2025.","stage":"filed, not approved","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/"},{"name":"ITM Isotope Technologies Munich","what":"68Ga-DPI-4452, a small peptide CAIX ligand with FDA Fast Track designation in November 2025 and a three-patient first-in-human report in the Journal of Nuclear Medicine.","stage":"early clinical","url":"https://jnm.snmjournals.org/"},{"name":"Philochem","what":"99mTc-PHC-102 with a five-patient cohort, and 68Ga-OncoCAIX with a clinical trial application submitted.","stage":"first-in-human","url":"https://www.philochem.ch/"},{"name":"Chinese academic programmes","what":"68Ga-NY104, a CAIX agent with a 47-patient cohort.","stage":"early clinical"}],"differentiation":"The alternative today is percutaneous renal mass biopsy, which is invasive, sometimes non-diagnostic and not universally offered, or surveillance, which defers the question. There is no blood test for renal cell carcinoma subtype. This is the rare imaging case where the competitor is a procedure rather than another test.","metrics":[{"label":"Sensitivity of 89Zr-girentuximab for clear cell renal cell carcinoma in ZIRCON","value":"85.5%","source":"Lancet Oncology 2024, 284 evaluable patients","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/"},{"label":"Specificity in the same trial","value":"87.0%","source":"ZIRCON, Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/39270701/"},{"label":"Surgically resected small renal masses that prove benign","value":"12.8% to 40% by size","source":"AUA guideline and published series","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2797464/"}],"risks":["The category may be closed before a second entrant arrives: if the manufacturing remediation succeeds, an approved antibody becomes the standard of care and the bar for a peptide rises to non-inferiority against an approved product.","A same-day ligand has to match an 85% and 87% benchmark set in a 284-patient phase 3, which is an expensive trial to run second.","Reimbursement for avoided surgery requires a health-economic case, not just accuracy."],"watch":["Whether the manufacturing complete response letter is resolved and TLX250-CDx is approved, which would reset the benchmark from unmet need to non-inferiority.","Accuracy data from any same-day CAIX peptide, particularly 68Ga-DPI-4452 after its Fast Track designation.","Any European filing, since no EMA submission for the antibody has been found."]},{"id":"opp-ceacam5-imaging-colorectal","kind":"opportunity","name":"CEACAM5 imaging for occult colorectal recurrence","aka":["CEA PET","CEACAM5 PET"],"tldr":"After bowel cancer surgery, a rising blood marker often signals that the cancer is back, but scans frequently cannot say where. The one scan ever approved for that exact problem was withdrawn from the market in 2005 and nothing has replaced it.","summary":"The clinical scenario is specific and common: a treated colorectal cancer patient's serum CEA rises during surveillance while CT, MRI and colonoscopy are normal or equivocal. Salvage surgery or ablation can still cure oligometastatic recurrence, but only if the disease can be localised. Arcitumomab (CEA-Scan), a technetium-99m anti-CEA antibody fragment approved for precisely this indication, was withdrawn from both the US and EU markets in 2005; clinicians now fall back on FDG PET/CT off-label, which in one referred series found recurrence in 56 of 88 such patients.\n\nMeanwhile the therapeutic side of CEACAM5 has grown: antibody-drug conjugates, T-cell engagers and CAR-T programmes target it, and the field has learned that CEA-directed therapy selection is not the same question as CEA-directed localisation. The most advanced CEACAM5-directed imaging agent in humans is not a PET tracer at all but SGM-101, a near-infrared fluorescent anti-CEA antibody for intraoperative use, now in a randomised phase 3 trial (NCT03659448, about 300 patients). For PET, the most advanced is the CEA-targeted nanobody 68Ga-HNI01 at first-in-human scale, nine patients.\n\nThe competitive picture changed independently of imaging. Tumour-informed ctDNA now detects recurrence a median of 5.9 months before radiological recurrence in GALAXY/CIRCULATE-Japan, and ctDNA-guided adjuvant therapy was non-inferior to standard management in DYNAMIC while halving chemotherapy use. ctDNA says whether and roughly when; it does not say where. That distinction is the whole of the case for a CEACAM5 tracer, and it is a stronger case now than when CEA-Scan was withdrawn, because more patients are being flagged as molecularly positive with nothing to localise.","asOf":"2026-09-23","links":[{"label":"FDG PET/CT for occult colorectal recurrence with raised CEA","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5153343/"},{"label":"NCT03659448: SGM-101 phase 3 in colorectal cancer","url":"https://clinicaltrials.gov/study/NCT03659448"},{"label":"GALAXY: ctDNA lead time over radiological recurrence, Nature Medicine 2024","url":"https://www.nature.com/articles/s41591-024-03254-6"},{"label":"DYNAMIC: ctDNA-guided adjuvant therapy in stage II colon cancer","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9701133/"},{"label":"CT nodal staging accuracy meta-analysis","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC13394594/"}],"tags":["unmet need first","colorectal","recurrence","ctDNA"],"related":["ga-68","f-18","tc-99m"],"indications":["colorectal-cancer"],"sections":[],"technologies":["immuno-pet","pet-ct","fdg-pet"],"targets":["ceacam5"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"unmet-need-first","unmetNeed":"When serum CEA or a ctDNA assay says a treated colorectal cancer has recurred but CT, MRI and colonoscopy cannot find it, no approved molecular imaging agent localises the disease well enough to plan salvage surgery.","useCase":"A colorectal multidisciplinary team would scan the patient whose CEA or ctDNA has turned positive with negative conventional imaging, to find and localise resectable recurrence, and would also use it for peritoneal and nodal mapping before an attempted curative resection. The output that matters is a lesion a surgeon can go to.","hypothesis":"A CEACAM5-specific PET agent will localise recurrent colorectal cancer in patients with rising CEA or detectable ctDNA and negative conventional imaging at a higher rate and with fewer false positives than FDG PET/CT, because it reports a lineage-specific antigen rather than glucose metabolism shared with inflammation.","rationale":"The target is expressed in the large majority of colorectal adenocarcinomas and the approach has regulatory precedent: an anti-CEA imaging agent was once approved for this indication. FDG PET/CT already works well enough in this setting to be used off-label, which establishes both that the clinical question is real and that the bar for a specific agent is a meaningful improvement over FDG rather than over nothing. The population being referred for localisation is growing because ctDNA surveillance flags molecular recurrence months before imaging, and antibody fragments and nanobodies now give same-day kinetics that arcitumomab's generation could not.","test":"A prospective study in patients with rising CEA or positive tumour-informed ctDNA and negative conventional imaging, comparing a CEACAM5 PET agent head to head with FDG PET/CT in the same patients, with histopathology or 12-month follow-up as the truth standard, and reporting the proportion of patients in whom the scan identified a resectable lesion that changed management.","maturity":"early-clinical","verdict":"standalone-and-companion","mostAdvanced":"SGM-101, a fluorescent anti-CEA antibody for intraoperative use from Surgimab, in a randomised phase 3 trial of about 300 patients; for PET specifically, the nanobody 68Ga-HNI01 at nine patients.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"CEACAM5 is a long-established colorectal lineage antigen; serum CEA is in every surveillance guideline, and an anti-CEA imaging agent was once approved for occult recurrence, so in-vivo targeting is proven in principle.","source":"Arcitumomab regulatory history","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5153343/"},{"domain":"clinical-evidence","state":"thin","why":"No CEACAM5 PET agent has gone beyond first-in-human; the nanobody 68Ga-HNI01 has nine patients. The only phase 3 CEA-directed imaging agent is a fluorescence agent for use in the operating theatre, not a tracer.","source":"NCT03659448 and first-in-human nanobody report","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC7892528/"},{"domain":"diagnostic-performance","state":"moderate","why":"The incumbent, FDG PET/CT, detected recurrence in 56 of 88 patients referred with raised CEA and negative conventional imaging, so any new agent must beat a working off-label comparator rather than fill a void.","source":"FDG PET/CT in occult colorectal recurrence","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5153343/","weighted":true},{"domain":"safety-dosimetry","state":"none","why":"No published dosimetry for a current-generation CEACAM5 PET agent at a scale worth quoting; the withdrawn technetium-99m fragment is not a guide to a gallium-68 or fluorine-18 construct."},{"domain":"regulatory-path","state":"moderate","why":"A direct precedent exists in the same indication, which is unusual: arcitumomab was approved for occult colorectal recurrence before being withdrawn in 2005, so the endpoint and claim structure have been accepted once.","source":"Arcitumomab history","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5153343/","weighted":true}],"flags":[{"category":"technical","flag":"amber","why":"Bowel and liver background is the hard part of abdominal imaging, and the antigen is shed into serum, which can blunt tumour uptake; a fragment or nanobody format is probably required."},{"category":"unmet-need","flag":"green","why":"A defined, guideline-recognised scenario with no approved agent since 2005, and a population growing because ctDNA surveillance flags recurrence earlier than imaging can localise it."},{"category":"ip","flag":"amber","why":"CEA binders are a crowded, decades-old space with many antibodies and fragments in therapeutic programmes; novelty would have to come from format and chelation rather than the binding site."},{"category":"commercial","flag":"amber","why":"The localisation use stands alone, but the scan is a one-off per recurrence episode in a surveillance population, so volume depends on how widely ctDNA surveillance is adopted."},{"category":"isotope","flag":"green","why":"Gallium-68 or fluorine-18 on a fragment gives same-day imaging; no supply constraint."},{"category":"competition","flag":"green","why":"No company has a disclosed late-stage CEACAM5 PET programme; the phase 3 activity is in fluorescence-guided surgery, which is complementary rather than competing."}],"competition":[{"name":"Surgimab","what":"SGM-101, a fluorescent anti-CEA antibody for intraoperative delineation of colorectal and peritoneal disease, in a randomised phase 3 trial of about 300 patients.","stage":"phase 3","url":"https://clinicaltrials.gov/study/NCT03659448"},{"name":"Academic nanobody programmes","what":"68Ga-HNI01, a CEA-targeted nanobody, first-in-human at nine patients.","stage":"phase 1","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC7892528/"},{"name":"ctDNA surveillance (Natera and others)","what":"Tumour-informed ctDNA detects recurrence a median of 5.91 months before radiological recurrence in GALAXY, creating the patients who need localising.","stage":"in clinical use","url":"https://www.nature.com/articles/s41591-024-03254-6"}],"differentiation":"Serum CEA misses up to 70% of recurrences and ctDNA says whether and when but not where: a positive ctDNA result with negative imaging is a management dilemma, not an answer. A CEACAM5 tracer competes with FDG PET/CT, not with the blood tests, and its case is specificity in an abdomen full of physiological FDG uptake.","metrics":[{"label":"Recurrences detected by FDG PET/CT in patients with raised CEA and negative conventional imaging","value":"56 of 88","source":"Occult recurrence series","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC5153343/"},{"label":"Lead time of tumour-informed ctDNA over radiological recurrence","value":"5.91 months median","source":"GALAXY, Nature Medicine 2024","url":"https://www.nature.com/articles/s41591-024-03254-6"},{"label":"Pooled sensitivity and specificity of CT for nodal staging in colorectal cancer","value":"69% and 66%","source":"Meta-analysis of 29 studies, 5,634 people","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC13394594/"},{"label":"Colorectal recurrences that occur without CEA elevation","value":"up to 70%","source":"Permanente Journal review","url":"https://www.thepermanentejournal.org/doi/10.7812/TPP/18-022"}],"risks":["FDG PET/CT is already good enough in this scenario for many teams, so the margin a specific agent must beat is not zero.","Shed circulating CEA can compete with tumour binding and blunt contrast, which is a formulation and format problem rather than a target problem.","If ctDNA-guided management moves toward treating molecular recurrence systemically without localising it, the surgical rationale for a localising scan narrows."],"watch":["The randomised SGM-101 phase 3 readout, which will show whether CEA-directed imaging changes surgical outcomes at all, in any modality.","Any CEACAM5 PET agent entering a trial with rising CEA or ctDNA positivity as the enrolment criterion rather than known measurable disease.","Guideline language on what to do with a positive ctDNA and a negative scan, which is where the demand for this agent will be written down."]},{"id":"opp-cldn18-2-imaging-gastric","kind":"opportunity","name":"Claudin-18.2 imaging when one biopsy says negative","aka":["CLDN18.2 PET","claudin 18.2 imaging"],"tldr":"Stomach cancer patients now get a drug only if a biopsy shows a protein called claudin-18.2. One biopsy core finds it only about six times in ten when the whole tumour has it, so patients are being refused a treatment on a test that misses.","summary":"Zolbetuximab is approved in the US, EU, Japan, China and elsewhere for CLDN18.2-positive, HER2-negative gastric and gastro-oesophageal junction adenocarcinoma, with patient selection by the VENTANA CLDN18 (43-14A) RxDx immunohistochemistry assay. Roughly 38% of screened patients in the pooled SPOTLIGHT and GLOW populations were positive at the 75%-of-tumour-cells threshold. In June 2026 China's regulator approved satricabtagene autoleucel, a CLDN18.2 CAR-T, in the same biomarker-defined population, so the number of decisions resting on this one assay is rising.\n\nThe assay's weakness is measurable. Against whole-tumour-section ground truth, a single representative biopsy gave 58.8% sensitivity for CLDN18.2, rising to 76.5% with six to eight biopsies, and a minimum of six endoscopic biopsies was needed to keep false negatives down; 18% of tumours were discordant between the primary and the matched nodal metastasis. A multi-laboratory ring trial found a 12% false-negative rate with 91% overall accuracy.\n\nThe imaging work is almost entirely Chinese and early: 68Ga-PMD22, 68Ga-NC-BCH and 124I-18B10(10L) each have a published pilot of 11 to 17 patients, and none has entered a multicentre or registration trial. The opportunity is therefore unusually well specified for a crossover case, because the incumbent test's failure rate is published and the decision it gates is binary.","asOf":"2026-09-23","links":[{"label":"Single-biopsy sensitivity for CLDN18.2, Scientific Reports 2025","url":"https://www.nature.com/articles/s41598-025-12337-4"},{"label":"CLDN18.2 positivity in pooled SPOTLIGHT and GLOW screening","url":"https://link.springer.com/article/10.1007/s10120-024-01518-1"},{"label":"First-in-human CLDN18.2 PET imaging","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC11149600/"},{"label":"Multi-laboratory ring trial of CLDN18.2 immunohistochemistry","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12647276/"},{"label":"Gastric cancer biomarker testing review, naming the approved assay","url":"https://www.cancerbiomed.org/content/22/3/212"}],"tags":["target crossover","gastric","companion diagnostic","sampling error"],"related":["ga-68","i-124"],"indications":["gastric-oesophageal-cancer"],"sections":[],"technologies":["immuno-pet","pet-ct"],"targets":["cldn18-2"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"target-crossover","unmetNeed":"When a gastric cancer biopsy reads CLDN18.2-negative, no test distinguishes a truly negative tumour from a false negative caused by sampling, so patients may be denied an approved antibody or CAR-T on a result that a single core gets right only about six times in ten.","useCase":"A gastrointestinal oncologist would order the scan for the patient whose biopsy is CLDN18.2-negative or equivocal but whose clinical situation makes the drug worth having, and for the patient whose only accessible tissue is an old primary specimen while the disease now sits in nodes and peritoneum. A positive scan would justify re-biopsy or treatment; a negative scan across all disease would close the question.","hypothesis":"Whole-body CLDN18.2 imaging will identify patients whose single-biopsy immunohistochemistry is falsely negative, at a rate consistent with the published 12% laboratory false-negative rate and the 41% single-core miss rate, and will thereby qualify patients for approved CLDN18.2-directed therapy who are currently refused it.","rationale":"Three independent Chinese groups have shown that CLDN18.2 can be imaged in patients, and the target is a tight-junction protein whose accessibility in tumour tissue is what makes the therapeutic antibody work. The incumbent test's failure mode is documented with numbers, from both a whole-section comparison and a ring trial, and 18% primary-versus-node discordance is exactly the kind of error whole-body imaging addresses. Two approved therapies now depend on this selection step, one of them a CAR-T, which raises the cost of a false negative.","test":"A prospective study in patients with gastric or junctional adenocarcinoma enrolling on the basis of a CLDN18.2-negative or equivocal biopsy, imaging all patients and then taking a protocol-mandated multi-core re-biopsy of a scan-positive lesion, with the primary endpoint being the proportion of scan-positive patients whose re-biopsy is positive at the label threshold. That design directly measures the false-negative rescue rate the case rests on.","maturity":"early-clinical","verdict":"companion-only","mostAdvanced":"Three Chinese first-in-human PET tracers (68Ga-PMD22, 68Ga-NC-BCH, 124I-18B10(10L)) with published pilots of 11 to 17 patients; none in a multicentre or registration trial.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"CLDN18.2 positivity at the 75% threshold was 38.4% across 4,507 patients screened for SPOTLIGHT and GLOW, and Astellas reports approximately 35% positivity in Chinese patients with advanced disease.","source":"Pooled screening analysis, Gastric Cancer 2024","url":"https://link.springer.com/article/10.1007/s10120-024-01518-1","weighted":true},{"domain":"clinical-evidence","state":"thin","why":"Three separate first-in-human tracer studies of 11 to 17 patients each, all single-centre and all in China; no comparative or multicentre data.","source":"Published pilot studies","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC11149600/"},{"domain":"diagnostic-performance","state":"moderate","why":"The case is built on the incumbent's measured failure: 58.8% sensitivity from one representative biopsy against whole-section truth, 76.5% with six to eight biopsies, 18% primary-versus-node discordance, and a 12% false-negative rate in a multi-laboratory ring trial.","source":"Naujoks et al., Scientific Reports 2025; ring trial","url":"https://www.nature.com/articles/s41598-025-12337-4","weighted":true},{"domain":"safety-dosimetry","state":"thin","why":"No adverse events reported in the small published cohorts; the iodine-124 construct carries a higher radiation burden than the gallium-68 ones, and no formal comparison has been published."},{"domain":"regulatory-path","state":"moderate","why":"An approved companion diagnostic already defines the claim: the VENTANA CLDN18 (43-14A) RxDx assay. An imaging agent would have to be positioned against it, most plausibly as an adjunct where tissue is inadequate rather than as a replacement.","source":"Gastric cancer biomarker review","url":"https://www.cancerbiomed.org/content/22/3/212"}],"flags":[{"category":"technical","flag":"amber","why":"Gastric wall and gastro-oesophageal junction imaging sits next to physiological uptake, and the published agents are antibody or antibody-fragment based with the kinetics that implies."},{"category":"unmet-need","flag":"green","why":"A binary treatment decision gated by a test with a published 12% laboratory false-negative rate and a 41% single-core miss rate against whole-section truth."},{"category":"ip","flag":"amber","why":"The binders come from therapeutic antibody programmes and the published imaging work sits with Chinese academic centres and their partners."},{"category":"commercial","flag":"amber","why":"Companion-only by construction, but tied to two approved therapies in a disease with an estimated 980,000 new cases a year, and the CAR-T approval raises the cost of a false negative."},{"category":"isotope","flag":"green","why":"Gallium-68 works for two of the three published agents; the iodine-124 version would be harder to distribute."},{"category":"competition","flag":"amber","why":"Three groups are already in humans, all in China, so a Western programme would be following rather than leading the science."}],"competition":[{"name":"Chinese academic PET programmes","what":"68Ga-PMD22, 68Ga-NC-BCH and 124I-18B10(10L), each with a published first-in-human pilot of 11 to 17 patients.","stage":"first-in-human","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC11149600/"},{"name":"Astellas","what":"Zolbetuximab (Vyloy), the approved CLDN18.2 antibody, selected by the VENTANA 43-14A RxDx immunohistochemistry companion diagnostic.","stage":"approved","url":"https://www.prnewswire.com/news-releases/chinas-national-medical-products-administration-nmpa-approves-vyloy-zolbetuximab-for-first-line-treatment-of-advanced-gastric-or-gastroesophageal-junction-adenocarcinoma-302342446.html"},{"name":"CARsgen Therapeutics","what":"Satricabtagene autoleucel, a CLDN18.2 CAR-T reported approved in China in June 2026 for the same biomarker-defined population.","stage":"approved in China","url":"https://chinamedwaypoint.com/resources/cancer-care/cancer-care-in-china/car-t-cell-therapy/ct041-satri-cel-cldn18-2-gastric-cancer-nmpa-approval"},{"name":"Roche Diagnostics","what":"The VENTANA CLDN18 (43-14A) RxDx assay, the incumbent companion diagnostic an imaging agent would be measured against.","stage":"approved companion diagnostic","url":"https://www.cancerbiomed.org/content/22/3/212"}],"differentiation":"The competitor is an approved immunohistochemistry companion diagnostic, not a blood test: liquid biopsy is not used clinically to determine CLDN18.2 status. Imaging does not offer a better biological measurement than histology; it offers coverage of every lesion at once, which is precisely the axis on which the tissue assay has been shown to fail.","metrics":[{"label":"Sensitivity of one representative biopsy for CLDN18.2 against whole-section truth","value":"58.8%","source":"Naujoks et al., Scientific Reports 2025","url":"https://www.nature.com/articles/s41598-025-12337-4"},{"label":"False-negative rate across laboratories in a CLDN18.2 immunohistochemistry ring trial","value":"12%","source":"Multi-laboratory ring trial","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12647276/"},{"label":"CLDN18.2 positivity at the 75% threshold in 4,507 screened patients","value":"38.4%","source":"Pooled SPOTLIGHT and GLOW screening, Gastric Cancer 2024","url":"https://link.springer.com/article/10.1007/s10120-024-01518-1"},{"label":"Tumours discordant between primary and matched nodal metastasis","value":"18%","source":"Naujoks et al., Scientific Reports 2025","url":"https://www.nature.com/articles/s41598-025-12337-4"}],"risks":["Regulators may not accept an imaging agent as an alternative route to a therapy whose label names a specific tissue assay, leaving the scan as an adjunct that nobody reimburses.","A scan threshold equivalent to the 75%-of-cells histology cut-off has not been defined, and defining it is a study in itself.","Three Chinese groups are ahead in the clinic, so a later entrant needs a better construct, not just a programme."],"watch":["Whether any of the three published tracers moves to a multicentre trial or reports agreement against the approved companion diagnostic.","Label expansions of CLDN18.2 therapies into earlier lines, which would multiply the number of selection decisions.","Any regulatory statement on non-tissue routes to establishing CLDN18.2 positivity."]},{"id":"opp-cxcr4-primary-aldosteronism","kind":"opportunity","name":"CXCR4 imaging instead of adrenal vein sampling","aka":["PentixaFor PET","CXCR4 PET in primary aldosteronism"],"tldr":"A common and curable cause of high blood pressure is almost never cured, because finding out which adrenal gland is at fault needs an invasive procedure few hospitals do well. A PET scan can answer the same question, and one is now heading into a registrational trial.","summary":"Primary aldosteronism accounts for 5 to 14% of all hypertension and 20 to 25% of treatment-resistant hypertension, and it can be cured by removing one adrenal gland if the excess comes from one side. Establishing which side requires adrenal vein sampling, an invasive procedure that the MATCH investigators describe as requiring a day off work, causing severe pain and hospitalisation in 1 to 3% of patients, available with a success rate above 50% in few hospitals. The consequence they report is stark: fewer than 1% of patients with primary aldosteronism are identified and fully investigated.\n\nThis is not a radiopharmaceutical looking for a use. It is the clearest standalone diagnostic case outside oncology, and it is already being built. 68Ga-PentixaFor from Pentixapharm holds EMA PRIME status granted in October 2024 and FDA Fast Track designation granted in July 2026, with an IND cleared and a phase 3 trial, PANDA, planned at approximately 270 patients in the United States. The academic evidence behind it is substantial: in a 100-patient prospective study, PET/CT agreed with adrenal vein sampling in 90% of patients against 54% for conventional CT, and a meta-analysis of seven studies covering 603 patients has been reported at pooled sensitivity 80% and specificity 91%.\n\nThe agent is also validated against pathology rather than just against another test: consistency between PET uptake and CXCR4 staining was 92.9%, and all 43 CYP11B2-positive functional nodules in one series were CXCR4-positive. What makes this record worth carrying is not that anything is missing, but that it is the field's best worked example of what an unmet-need-first opportunity looks like when it succeeds.","asOf":"2026-09-23","links":[{"label":"MATCH: molecular imaging against adrenal vein sampling, Nature Medicine 2023","url":"https://www.nature.com/articles/s41591-022-02114-5"},{"label":"68Ga-pentixafor against adrenal vein sampling in 100 patients, JAMA Network Open 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9936343/"},{"label":"FDA Fast Track designation for 68Ga-PentixaFor in primary aldosteronism","url":"https://www.eqs-news.com/news/corporate/pentixapharm-receives-fda-fast-track-designation-for-phase-3-diagnostic-candidate-e281b6e281b8gaga-pentixafor-in-primary-aldosteronism/239d14bc-6e9e-4077-9909-43e52edf7a09_en"},{"label":"EMA PRIME status for 68Ga-PentixaFor","url":"https://www.pentixapharm.com/news/ema-grants-prime-status-to-pentixapharms-lead-candidate-pentixafor"},{"label":"68Ga-pentixafor dosimetry, J Nucl Med 2015","url":"https://jnm.snmjournals.org/content/56/3/410"},{"label":"Endocrine Society primary aldosteronism guideline 2025","url":"https://www.endocrine.org/clinical-practice-guidelines/primary-aldosteronism-2"}],"tags":["unmet need first","standalone diagnostic","non-oncology","hypertension"],"related":["ga-68"],"indications":["primary-aldosteronism"],"sections":[],"technologies":["pet-ct","pet"],"targets":["cxcr4"],"drugs":["ga-68-pentixafor"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"unmet-need-first","unmetNeed":"A curable cause of hypertension goes untreated because the test that decides who can be cured is invasive, painful, available in few centres and therefore almost never done: fewer than 1% of patients with primary aldosteronism are fully investigated.","useCase":"An endocrinologist or hypertension specialist with a confirmed diagnosis of primary aldosteronism would use the scan to decide between adrenalectomy and lifelong medical therapy, replacing adrenal vein sampling. The value is measured in operations correctly offered, not in lesions detected.","hypothesis":"CXCR4-targeted PET will lateralise primary aldosteronism accurately enough to replace adrenal vein sampling, and by removing the invasive step will raise the proportion of patients investigated and cured well above the current figure of fewer than 1%.","rationale":"CXCR4 is expressed on aldosterone-producing tissue and tracks the pathology marker: all CYP11B2-positive functional nodules in one series were CXCR4-positive, with 92.9% consistency between PET uptake and staining. Against the invasive reference standard, PET/CT concordance was 90% against CT's 54% in 100 patients, and surgical outcomes support it, with complete biochemical and clinical success of 91.67% and 100% in 36 patients operated on the basis of PET lateralisation. The molecular-imaging approach has already been shown non-inferior to adrenal vein sampling with a different tracer in the MATCH trial, so the regulatory logic is established.","test":"The registrational design is already defined: a multicentre trial benchmarking PET lateralisation against a performance standard derived from guideline-based diagnosis, with post-adrenalectomy biochemical and clinical cure as the outcome that matters. The open question this record tracks is whether phase 3 reproduces the 90% concordance seen in single-centre studies.","maturity":"being-tested-at-scale","verdict":"standalone-only","mostAdvanced":"68Ga-PentixaFor (Pentixapharm Holding AG): EMA PRIME status October 2024, FDA Fast Track July 2026, IND cleared, phase 3 PANDA planned at approximately 270 patients in the United States with US launch targeted for 2030.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"All 43 CYP11B2-positive functional nodules in one series were CXCR4-positive, and consistency between PET uptake and CXCR4 staining was 92.9%, tying the imaging signal directly to the enzyme that makes aldosterone.","source":"Functional nodules study, PMID 36070092","url":"https://pubmed.ncbi.nlm.nih.gov/36070092/","weighted":true},{"domain":"clinical-evidence","state":"strong","why":"Multiple completed prospective studies including 100 patients against adrenal vein sampling, 120 patients with pathology correlation, and a randomised 320-patient trial recruiting in China; an approximately 270-patient US phase 3 is planned.","source":"Hu et al., JAMA Network Open 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9936343/","weighted":true},{"domain":"diagnostic-performance","state":"strong","why":"PET/CT agreed with adrenal vein sampling in 90 of 100 patients against 54 of 100 for conventional CT; a reported meta-analysis of seven studies and 603 patients gives pooled sensitivity 80% and specificity 91% with an AUC of 0.91.","source":"Hu et al., JAMA Network Open 2023; meta-analysis via a 2026 review","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9936343/","weighted":true},{"domain":"safety-dosimetry","state":"strong","why":"Effective dose from 150 MBq of 68Ga-pentixafor is 2.3 mSv, with the highest organ dose in the bladder wall at 12.2 mGy; a 2025 dosimetry paper reports 1.65 plus or minus 0.06 mSv for the same activity, both far below the 7 mSv of a standard FDG scan.","source":"Herrmann et al., J Nucl Med 2015","url":"https://jnm.snmjournals.org/content/56/3/410","weighted":true},{"domain":"regulatory-path","state":"strong","why":"EMA PRIME and FDA Fast Track are both granted for this exact indication, the IND has cleared, and written FDA minutes reportedly identified no major concerns with the phase 3 design.","source":"Pentixapharm and EQS releases","url":"https://www.eqs-news.com/news/corporate/pentixapharm-receives-fda-fast-track-designation-for-phase-3-diagnostic-candidate-e281b6e281b8gaga-pentixafor-in-primary-aldosteronism/239d14bc-6e9e-4077-9909-43e52edf7a09_en","weighted":true}],"flags":[{"category":"technical","flag":"green","why":"Gallium-68 small-molecule ligand, same-day imaging, effective dose around 2 mSv, and pathology-validated uptake."},{"category":"unmet-need","flag":"green","why":"A curable disease in 5 to 14% of all hypertension where fewer than 1% of patients are fully investigated because the deciding test is invasive."},{"category":"ip","flag":"red","why":"The ligand was patented at the University of Würzburg and exclusively licensed to Pentixapharm in 2019, so the lead chemical series is not available."},{"category":"commercial","flag":"green","why":"Purely standalone: the scan replaces a procedure and depends on no drug approval, which is the strongest commercial structure a diagnostic can have."},{"category":"isotope","flag":"green","why":"Gallium-68 from a generator; no supply constraint."},{"category":"competition","flag":"red","why":"One sponsor holds PRIME, Fast Track and a cleared IND in this indication, and the metomidate tracers are an established academic alternative; a new entrant would be third at best."}],"competition":[{"name":"Pentixapharm Holding AG","what":"68Ga-PentixaFor: EMA PRIME, FDA Fast Track, IND cleared, phase 3 PANDA planned at approximately 270 patients, US launch targeted 2030.","stage":"phase 3 planned","url":"https://www.pentixapharm.com/news/ema-grants-prime-status-to-pentixapharms-lead-candidate-pentixafor"},{"name":"National Cancer Institute and NIDDK","what":"Investigator-initiated phase 2 of 68Ga-PentixaFor in hyperaldosteronism and hypercortisolism, 80 patients estimated.","stage":"phase 2 recruiting","url":"https://clinicaltrials.gov/study/NCT06246357"},{"name":"First Affiliated Hospital of Chongqing Medical University","what":"Multicentre randomised trial of PET/CT-guided against adrenal-vein-sampling-guided treatment, 320 participants estimated.","stage":"recruiting","url":"https://classic.clinicaltrials.gov/ct2/show/NCT06238232"},{"name":"UK academic consortium (Barts, Cambridge, Guy's)","what":"[11C]metomidate and [18F]CETO, the non-CXCR4 precedent: molecular imaging reported non-inferior to adrenal vein sampling in MATCH, 146 patients.","stage":"published","url":"https://www.nature.com/articles/s41591-022-02114-5"}],"differentiation":"The aldosterone-to-renin ratio screens for the disease but does not say which side; CYP11B2 immunohistochemistry confirms the answer only after the gland has been removed; and no blood or ctDNA test lateralises the disease before surgery. The comparator here is an invasive procedure, not another scan, which is why the health-economic case is unusually direct.","metrics":[{"label":"Concordance of 68Ga-pentixafor PET/CT with adrenal vein sampling against CT","value":"90 of 100 patients against 54 of 100","source":"Hu et al., JAMA Network Open 2023","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9936343/"},{"label":"Primary aldosteronism as a share of all hypertension","value":"5 to 14%","source":"Wu et al., Nature Medicine 2023","url":"https://www.nature.com/articles/s41591-022-02114-5"},{"label":"Patients with primary aldosteronism identified and fully investigated","value":"fewer than 1%","source":"Wu et al., Nature Medicine 2023","url":"https://www.nature.com/articles/s41591-022-02114-5"},{"label":"Post-adrenalectomy complete biochemical and clinical success after PET-guided surgery in bilateral lesions","value":"91.67% and 100% of 36 patients","source":"EJNMMI Research 2025","url":"https://link.springer.com/article/10.1186/s13550-025-01309-4"},{"label":"Effective dose from 150 MBq of 68Ga-pentixafor","value":"2.3 mSv","source":"Herrmann et al., J Nucl Med 2015","url":"https://jnm.snmjournals.org/content/56/3/410"}],"risks":["Single-centre concordance of 90% may not survive a multicentre phase 3 with central reading.","The indication sits with endocrinologists and hypertension specialists who do not routinely order PET, so adoption is a referral-pathway problem as much as an accuracy one.","The chemical series is exclusively licensed, so this is a record to learn the method from rather than an opening to enter."],"watch":["Registration of PANDA on ClinicalTrials.gov and its first patient enrolled, expected in the second half of 2026 per the sponsor.","The Chongqing randomised trial, which is the only design that tests whether PET-guided treatment produces the same cures as sampling-guided treatment.","Whether guideline bodies begin to name molecular imaging as an alternative to adrenal vein sampling."]},{"id":"opp-dll3-imaging-sclc","kind":"opportunity","name":"DLL3 imaging for small-cell lung cancer","aka":["DLL3 PET","delta-like ligand 3 imaging"],"tldr":"A drug that attacks small-cell lung cancer through a protein called DLL3 is already approved, but there is no approved scan that shows whether a patient's tumours still carry that protein. Doctors decide from a single biopsy taken from one place, which cannot show what the rest of the disease is doing.","summary":"Tarlatamab, a DLL3-directed bispecific T-cell engager, received accelerated FDA approval on 16 May 2024 and traditional approval on 19 November 2025, and DLL3-directed antibody-drug conjugates, CAR-T cells and a second T-cell engager (obrixtamig) are in trials. Patient selection rests on tissue immunohistochemistry from one archival or fresh biopsy. DLL3 is expressed in 85% of small-cell lung cancers at a 25% cut-off in the largest real-world series (895 of 1,050 patients), so most patients qualify on a single sample, but nothing in routine practice shows whether every metastatic site still expresses the target.\n\nOne imaging agent has human data. The zirconium-89-labelled anti-DLL3 antibody 89Zr-DFO-SC16.56, run investigator-initiated at Memorial Sloan Kettering under NCT04199741, was reported in Lancet Oncology in 2024: 18 patients, DLL3-avid tumours delineated on a single scan in 12 of 15 patients in the expansion cohort, uptake congruent with DLL3 immunohistochemistry in 15 of 16 patients with evaluable tissue, mean effective dose 0.49 mSv/MBq, one grade 1 allergic reaction and no grade 2 or worse adverse events. The trial is still recruiting with an estimated 105 patients. A gallium-68 DLL3 tracer opened in China in May 2026 (NCT07677787, 20 patients planned) and has not reported. A next-generation MSK construct, 89Zr-DFO-TDI-Y-010, with a lutetium-177 therapeutic pair, is preclinical.\n\nThe gap is therefore not biological plausibility, which a published 94% concordance with immunohistochemistry supports, but the absence of any industry-sponsored development path: the only clinical agent is an academic antibody with multi-day imaging kinetics, and no DLL3 imaging agent has been filed with any regulator.","asOf":"2026-09-23","links":[{"label":"First-in-human DLL3 immuno-PET, Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38950555/"},{"label":"NCT04199741: 89Zr-DFO-SC16.56 immuno-PET of neuroendocrine tumours","url":"https://clinicaltrials.gov/study/NCT04199741"},{"label":"NCT07677787: DLL3-targeted PET/CT in small-cell lung cancer (gallium-68)","url":"https://clinicaltrials.gov/study/NCT07677787"},{"label":"DLL3 expression in 1,050 patients, Lung Cancer 2020","url":"https://pubmed.ncbi.nlm.nih.gov/32745892/"},{"label":"FDA: accelerated approval of tarlatamab, May 2024","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-tarlatamab-extensive-stage-small-cell-lung-cancer"}],"tags":["theranostic gap","companion diagnostic","lung","neuroendocrine"],"related":["zr-89","ga-68","lu-177"],"indications":["sclc"],"sections":[],"technologies":["immuno-pet","pet-ct"],"targets":["dll3"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"theranostic-gap","unmetNeed":"Before starting a DLL3-directed T-cell engager, no test shows whether every metastatic site in a patient with small-cell lung cancer still expresses DLL3, or whether some lesions have lost it; the decision rests on one biopsy from one place.","useCase":"A medical oncologist or nuclear medicine physician would scan a patient with extensive-stage small-cell lung cancer, or a patient with suspected neuroendocrine transformation of a lung or prostate adenocarcinoma, before committing to a DLL3-directed therapy. A whole-body map of DLL3-avid and DLL3-negative disease would either confirm the target or redirect the patient to another line, and would give a baseline for judging loss of target at progression.","hypothesis":"A same-day DLL3 imaging agent, built on a small molecule, peptide or antibody fragment rather than a full antibody, would agree with tissue immunohistochemistry at least as well as the published antibody tracer while capturing between-lesion heterogeneity that a single biopsy misses, and would identify the minority of patients whose disease has lost DLL3 before they are exposed to a T-cell engager.","rationale":"The published first-in-human antibody data already show target-specific uptake that tracks immunohistochemistry in 15 of 16 evaluable patients, so the target is reachable in vivo. DLL3 is expressed in the large majority of small-cell lung cancers but not uniformly, and DLL3-directed therapy carries a cytokine-release and neurotoxicity burden that makes treating a target-negative patient costly. The limitation of the existing agent is pharmacokinetic rather than biological: a zirconium-89 antibody requires imaging three to six days after injection, which no routine oncology service can absorb at scale.","test":"A prospective study of a same-day DLL3 tracer in patients starting a DLL3-directed T-cell engager, powered on the agreement between scan-positive and immunohistochemistry-positive disease on a per-lesion basis with biopsy as the truth standard in accessible lesions, and reporting how often the scan finds a target-negative lesion in a patient whose biopsy was target-positive. The response rate of scan-positive against scan-negative patients would be the secondary endpoint that decides whether the scan should gate treatment.","maturity":"early-clinical","verdict":"companion-only","mostAdvanced":"89Zr-DFO-SC16.56, an academic anti-DLL3 antibody tracer at Memorial Sloan Kettering, phase 1/2 and still recruiting under NCT04199741, with 18 patients published in Lancet Oncology in 2024.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"DLL3 is expressed in 895 of 1,050 small-cell lung cancers (85%) at a 25% tumour-cell cut-off, and in 68% at a 75% cut-off, in the largest international real-world immunohistochemistry series.","source":"Rojo et al., Lung Cancer 2020;147:237-243","url":"https://pubmed.ncbi.nlm.nih.gov/32745892/","weighted":true},{"domain":"clinical-evidence","state":"thin","why":"One published first-in-human cohort of 18 patients with an antibody tracer; the trial continues to an estimated 105 patients. No second agent has reported human data.","source":"Tendler et al., Lancet Oncology 2024;25:1015-1024","url":"https://pubmed.ncbi.nlm.nih.gov/38950555/"},{"domain":"diagnostic-performance","state":"moderate","why":"A single scan delineated DLL3-avid tumour in 12 of 15 patients, and uptake agreed with tissue immunohistochemistry in 15 of 16 patients with evaluable tissue. No study yet relates scan findings to response on DLL3-directed therapy.","source":"Tendler et al., Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38950555/","weighted":true},{"domain":"safety-dosimetry","state":"moderate","why":"Mean effective dose 0.49 mSv/MBq with the highest absorbed organ dose in liver at 1.83 mGy/MBq; one grade 1 allergic reaction in 18 patients and no grade 2 or worse events.","source":"Tendler et al., Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38950555/"},{"domain":"regulatory-path","state":"thin","why":"No DLL3 imaging agent has been filed anywhere. The nearest precedent for a receptor-status tracer is 68Ga-DOTATATE, approved in 2016 on localisation performance against a reference standard rather than an outcome endpoint.","source":"NETSPOT FDA label","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/208547lbl.pdf"}],"flags":[{"category":"technical","flag":"amber","why":"The only clinical agent is a full antibody needing imaging three to six days after injection, which does not fit a routine service. A same-day construct exists only preclinically."},{"category":"unmet-need","flag":"amber","why":"Real but narrow: because DLL3 is expressed in most small-cell lung cancers, a scan changes management mainly in the minority with heterogeneous or lost expression, and that fraction has not been measured prospectively."},{"category":"ip","flag":"amber","why":"The lead antibody and its next-generation successor are institutionally owned at Memorial Sloan Kettering; freedom to operate for an independent construct is unexamined in public sources."},{"category":"commercial","flag":"red","why":"Sales would depend on the DLL3 therapy market, and small-cell lung cancer is a small, short-lived population with no standalone diagnostic question of its own."},{"category":"isotope","flag":"green","why":"Any of gallium-68, fluorine-18 or copper-64 would suit a small-molecule or fragment construct; the published antibody uses zirconium-89, which is cyclotron-made but established."},{"category":"competition","flag":"green","why":"Only one academic agent has human data and one Chinese tracer has just opened; no company has a disclosed clinical DLL3 imaging programme."}],"competition":[{"name":"Memorial Sloan Kettering Cancer Center","what":"89Zr-DFO-SC16.56, the only DLL3 tracer with published human data, and a preclinical successor pair 89Zr-DFO-TDI-Y-010 with 177Lu therapy.","stage":"phase 1/2 recruiting","url":"https://clinicaltrials.gov/study/NCT04199741"},{"name":"First Affiliated Hospital of Xiamen University","what":"A gallium-68 DLL3-targeted PET tracer; 20 patients planned, opened May 2026, no results published.","stage":"recruiting","url":"https://clinicaltrials.gov/study/NCT07677787"},{"name":"Amgen","what":"Tarlatamab, the approved DLL3 T-cell engager that creates the demand; selection is by tissue immunohistochemistry, not imaging.","stage":"approved","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-tarlatamab-extensive-stage-small-cell-lung-cancer"},{"name":"Boehringer Ingelheim","what":"Obrixtamig, a second DLL3 T-cell engager in DLL3-positive small-cell lung cancer and other neuroendocrine tumours.","stage":"active, not recruiting","url":"https://clinicaltrials.gov/study/NCT04429087"}],"differentiation":"The competing test is DLL3 immunohistochemistry on tissue, which is already used to enrol patients in trials. No blood or ctDNA test for DLL3 status exists. Imaging would add whole-body coverage and repeatability rather than a new biological readout, which is exactly why its value depends on how often lesions within one patient disagree.","metrics":[{"label":"Small-cell lung cancers expressing DLL3 in at least 25% of tumour cells","value":"85%","source":"Rojo et al., Lung Cancer 2020 (895 of 1,050)","url":"https://pubmed.ncbi.nlm.nih.gov/32745892/"},{"label":"Patients in whom one scan delineated DLL3-avid tumour","value":"12 of 15","source":"Tendler et al., Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38950555/"},{"label":"Agreement between tracer uptake and tissue immunohistochemistry","value":"15 of 16","source":"Tendler et al., Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38950555/"}],"risks":["If almost every patient is DLL3-positive on biopsy, a scan that confirms it adds cost without changing management; the case rests on heterogeneity that has not been quantified prospectively.","The market is tied to one therapy class in one small indication, so a companion-only agent carries the therapy's commercial risk without any standalone use to fall back on.","A full antibody cannot be delivered at service scale; whoever wants this needs a same-day construct, and the published work does not provide one."],"watch":["Readout of the expansion cohort of NCT04199741, which would take the published series from 18 to a larger number of patients.","First results from the gallium-68 DLL3 tracer at Xiamen (NCT07677787), the first non-antibody agent in humans.","Any registered trial of the MSK next-generation 89Zr-DFO-TDI-Y-010 or its lutetium-177 pair, which would signal the field moving to a theranostic construct."]},{"id":"opp-fap-pancreatic-staging","kind":"opportunity","name":"FAP imaging to stop futile pancreatic surgery","aka":["FAPI PET in PDAC"],"tldr":"Four in ten pancreatic cancer patients whose scans say the tumour can be removed turn out, once opened up, to have disease that cannot be removed. A scan that lights up the scar tissue around tumour deposits sees more of that hidden disease than the standard one.","summary":"The number that defines this opportunity comes from a Cochrane review: the median pre-test probability of unresectable disease after CT was 41.4%, meaning 41 of 100 participants whose cancer looked resectable on CT were found unresectable at laparotomy. The operation that follows is major surgery with no curative benefit.\n\nFAP imaging attacks that gap directly, because pancreatic ductal adenocarcinoma is a stroma-rich tumour and the tracer reports the fibroblast compartment rather than glucose uptake. A 62-patient prospective study of 18F-FAPI-04 against FDG upgraded the TNM stage in 14 patients, with higher uptake in primary tumours, nodes, liver and peritoneal deposits, and FDG missed one patient with cancer that FAPI found. A PDAC-specific meta-analysis of 7 studies and 322 patients gives pooled sensitivity of 0.99 against 0.84 for FDG with comparable specificity. A 20-patient Korean study found FAPI-74 detected metastatic nodes in 50% of cases against 0% for FDG.\n\nThe gap in the evidence is precise and worth stating: no trial has yet reported that FAPI-based selection reduces the non-curative laparotomy rate. The completed SOFIE phase 2 (NCT05262855, 63 patients) measured sensitivity against histopathology, not operations avoided. On the therapy side the picture is discouraging — FRONTIER was terminated early for rapid clearance and low tumour doses, and across eight compassionate-use patients the predominant outcome was radiological progression — which strengthens the case for treating this as a diagnostic opportunity rather than a theranostic one.","asOf":"2026-09-23","links":[{"label":"Cochrane review: unresectable disease found at laparotomy after CT","url":"https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.cd009323.pub3/full"},{"label":"18F-FAPI-04 against FDG in 62 patients, J Nucl Med 2024","url":"https://jnm.snmjournals.org/content/jnumed/65/2/206.full.pdf"},{"label":"NCT05262855: [68Ga]FAPI-46 phase 2 in pancreatic cancer","url":"https://clinicaltrials.gov/study/NCT05262855"},{"label":"[18F]AlF-FAPI-74 in potentially resectable pancreatic cancer","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC11634952/"},{"label":"FRONTIER terminated early for rapid clearance","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12607575/"}],"tags":["unmet need first","pancreas","surgical selection","stroma"],"related":["ga-68","f-18","lu-177"],"indications":["pancreatic-cancer"],"sections":[],"technologies":["fapi-pet","pet-ct","fdg-pet"],"targets":["fap"],"drugs":["ga-68-fapi-46","fap-2286"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"unmet-need-first","unmetNeed":"No validated test tells a pancreatic tumour board, before operating, whether a CT-resectable tumour hides peritoneal or small liver metastases, and 41.4% of CT-resectable patients are found unresectable at laparotomy.","useCase":"A hepatobiliary surgeon and tumour board would scan every patient considered for resection or for neoadjuvant therapy, and would cancel or defer surgery on the strength of peritoneal or hepatic deposits that CT cannot see. The endpoint that matters is operations not performed.","hypothesis":"FAP-directed PET before pancreatic resection will identify CT-occult peritoneal and hepatic metastases often enough to reduce the non-curative laparotomy rate below the 41.4% that follows CT staging alone.","rationale":"Pancreatic ductal adenocarcinoma is defined by its fibroblast-rich stroma, which is why a tracer aimed at fibroblast activation protein has repeatedly outperformed FDG in this disease specifically: pooled sensitivity 0.99 against 0.84 across 322 patients, stage upgraded in 14 of 62 patients in a prospective head-to-head, and peritoneal disease visible where FDG showed nothing. Multiple isotopes and constructs work, including fluorine-18 versions that can be distributed. The missing step is not proof of detection but proof of consequence.","test":"A prospective study in patients deemed resectable on CT, imaging all of them with a FAP tracer, with a pre-specified rule for when a FAPI-positive extra-pancreatic finding cancels or alters surgery, and the primary endpoint being the non-curative laparotomy rate against the 41.4% historical benchmark. Histology or laparoscopy must confirm every scan-positive finding that changes management.","maturity":"being-tested-at-scale","verdict":"standalone-and-companion","mostAdvanced":"[68Ga]FAPI-46 from SOFIE: a completed prospective multicentre phase 2 in resectable or borderline resectable pancreatic ductal adenocarcinoma, 63 patients, with histopathology as truth standard (NCT05262855). On the therapy side, 177Lu-FAP-2286 in Novartis's LuMIERE phase 1/2 (NCT04939610).","dueDiligence":[{"domain":"target-biology","state":"strong","why":"Pancreatic ductal adenocarcinoma is stroma-rich and fibroblast activation protein is expressed in the tumour stroma rather than the tumour cells, which is why uptake exceeds FDG in primary tumours, nodes and peritoneal deposits.","source":"Wang et al., J Nucl Med 2024","url":"https://jnm.snmjournals.org/content/jnumed/65/2/206.full.pdf","weighted":true},{"domain":"clinical-evidence","state":"strong","why":"A completed prospective multicentre phase 2 of 63 patients with histopathology truth standard, a 62-patient prospective head-to-head against FDG, a 20-patient resectability cohort, and a PDAC-specific meta-analysis of 7 studies and 322 patients.","source":"NCT05262855 and Hu et al. meta-analysis","url":"https://clinicaltrials.gov/study/NCT05262855","weighted":true},{"domain":"diagnostic-performance","state":"strong","why":"Pooled sensitivity 0.99 (0.97 to 1.00) for FAPI against 0.84 (0.70 to 0.92) for FDG with comparable specificity across 322 patients; stage upgraded in 14 of 62 patients in a prospective comparison.","source":"PDAC-specific meta-analysis, Academic Radiology 2025","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12890629/","weighted":true},{"domain":"safety-dosimetry","state":"moderate","why":"Diagnostic FAPI agents have been used across many published cohorts without reported safety signals; on the therapeutic side whole-body effective dose for 177Lu-FAPI-XT was 0.039 plus or minus 0.013 Sv/GBq.","source":"Phase 1 dose escalation report","url":"https://pubmed.ncbi.nlm.nih.gov/41087606/"},{"domain":"regulatory-path","state":"thin","why":"No FAP imaging agent is approved anywhere, and no trial has yet used a management endpoint such as avoided laparotomy, which is the claim this opportunity actually needs.","source":"NCT05262855 primary outcome","url":"https://clinicaltrials.gov/study/NCT05262855"}],"flags":[{"category":"technical","flag":"green","why":"Works with both gallium-68 and fluorine-18 constructs, same-day imaging, and repeatedly reproduced across independent centres."},{"category":"unmet-need","flag":"green","why":"A 41.4% futile-laparotomy rate after CT staging is a large, quantified, guideline-recognised failure of current imaging."},{"category":"ip","flag":"red","why":"The FAPI chemical space is crowded with FAPI-04, FAPI-46, FAPI-74, FAP-2286 and numerous derivatives across multiple sponsors and academic groups."},{"category":"commercial","flag":"green","why":"Standalone: the value is surgery avoided, which needs no drug approval, and a FAP-directed therapy would be an additional rather than a necessary use."},{"category":"isotope","flag":"green","why":"Gallium-68 and fluorine-18 both established; the therapeutic side would need lutetium-177 or an alpha emitter."},{"category":"competition","flag":"red","why":"A completed multicentre phase 2 exists, Novartis holds the leading therapeutic, and numerous academic groups publish in this space."}],"competition":[{"name":"SOFIE Biosciences","what":"[68Ga]FAPI-46 phase 2 in resectable and borderline resectable pancreatic ductal adenocarcinoma, 63 patients, completed, histopathology truth standard.","stage":"phase 2 complete","url":"https://clinicaltrials.gov/study/NCT05262855"},{"name":"Novartis","what":"177Lu-FAP-2286 in LuMIERE, phase 1/2, 222 planned; phase 1 had 27 patients including 9 with pancreatic cancer, with one partial response and nine stable.","stage":"phase 1/2","url":"https://clinicaltrials.gov/study/NCT04939610"},{"name":"Chinese and Korean academic groups","what":"18F-FAPI-04 in 62 patients prospectively against FDG, and [18F]AlF-FAPI-74 in 20 potentially resectable patients.","stage":"published prospective studies","url":"https://jnm.snmjournals.org/content/jnumed/65/2/206.full.pdf"},{"name":"POINT Biopharma","what":"177Lu-PNT6555 in FRONTIER, terminated early because rapid clearance gave low tumour absorbed doses and limited efficacy.","stage":"terminated","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12607575/"}],"differentiation":"The comparators are CT, which leaves a 41.4% futile-laparotomy rate, and staging laparoscopy, which is itself an operation. CA 19-9 is neither sensitive nor specific enough to decide resectability, and FDG PET is not standard in this disease. FAP imaging is differentiated because pancreatic cancer is the tumour where the stromal target is most abundant and FDG performs worst.","metrics":[{"label":"CT-resectable patients found unresectable at laparotomy","value":"41.4% median pre-test probability","source":"Cochrane review, Allen et al. 2016","url":"https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.cd009323.pub3/full"},{"label":"Pooled sensitivity of FAPI against FDG in pancreatic ductal adenocarcinoma","value":"0.99 against 0.84 across 7 studies and 322 patients","source":"Hu et al., Academic Radiology 2025, via review","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12890629/"},{"label":"Patients whose TNM stage was upgraded by 18F-FAPI-04 against FDG","value":"14 of 62","source":"Wang et al., J Nucl Med 2024","url":"https://jnm.snmjournals.org/content/jnumed/65/2/206.full.pdf"},{"label":"Metastatic lymph node detection, FAPI-74 against FDG","value":"50% against 0% of 10","source":"20-patient prospective cohort","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC11634952/"}],"risks":["FAP is expressed in wound healing, pancreatitis and other fibrotic conditions, so specificity in a chronically inflamed pancreas is the obvious failure mode and needs its own dataset.","Detection superiority does not automatically translate into fewer futile operations; a surgeon will not cancel an operation on an unbiopsied peritoneal signal without prospective evidence.","The therapeutic side of FAP is going badly, with one terminated trial and mostly progression in compassionate use, so a theranostic pitch would be weak."],"watch":["Publication of the SOFIE phase 2 results and whether any follow-on trial adopts avoided laparotomy as an endpoint.","Specificity data in chronic pancreatitis and post-treatment fibrosis, which is where this agent will either hold up or fail.","Whether FAP-directed therapy recovers after FRONTIER, which determines if a companion use ever exists."]},{"id":"opp-gpc3-hcc-china","kind":"opportunity","name":"GPC3 imaging of the indeterminate liver nodule, led from China","aka":["GPC3 PET","glypican-3 imaging"],"tldr":"Cirrhotic livers throw up nodules that scans cannot classify, and the usual answer is to wait three to six months to see if they grow. Several Chinese hospital programmes are testing tracers that recognise a protein carried by most liver cancers, and almost none of that work appears in Western pipeline reviews.","summary":"This record exists partly to demonstrate the non-US-registry lens. The clinical problem is well defined: using the CT/MRI LI-RADS algorithm, the pooled proportion of hepatocellular carcinoma is 31% for LR-3 and 64% for LR-4 observations, so a large share of nodules sit in categories that neither confirm nor exclude cancer, and the management default is serial imaging. Glypican-3 is overexpressed in 70 to 80% of hepatocellular carcinomas and virtually absent in normal adult liver and benign hepatic lesions, which is an unusually clean contrast for a liver target.\n\nThe programmes divide along geography. The most mature single dataset is Western: [68Ga]Ga-RAYZ-8009 from RayzeBio, now part of Bristol Myers Squibb, with a 24-patient first-in-human case series run in the Netherlands and Germany, no adverse events, and tumour-to-liver ratios averaging 8.3 at about an hour. A related investigator-initiated cohort in India reported 64 patients scanned with 92% showing at least one positive lesion. But the deepest programme is at Wuhan Union Hospital: 68Ga-XH06, an antibody-fragment immunoPET agent registered as NCT06383520 with 100 patients estimated, published as a 5-patient pilot in EJNMMI and an 8-patient first-in-human study in Clinical Cancer Research, with conference cohorts of 30 and 36 patients reporting sensitivity of 90.63% and specificity of 100% against pathology in one data cut and 91.7% and 83.3% in another. A head-to-head against enhanced MRI is registered at 150 patients, and a further 40-patient study is recruiting at Xiamen.\n\nNo GPC3 imaging agent has FDA, EMA or NMPA marketing approval. The point of the record is that a landscape review built only on ClinicalTrials.gov Western entries would see the 24-patient case series and miss the registered 100- and 150-patient Chinese studies behind it.","asOf":"2026-09-23","links":[{"label":"LI-RADS: pooled proportion of hepatocellular carcinoma by category, Radiology 2023","url":"https://pubs.rsna.org/doi/full/10.1148/radiol.222801"},{"label":"[68Ga]Ga-RAYZ-8009 first-in-human case series, J Nucl Med 2024","url":"https://pubmed.ncbi.nlm.nih.gov/39362766/"},{"label":"NCT06383520: GPC3-targeted PET imaging in hepatocellular carcinoma, Wuhan","url":"https://clinicaltrials.gov/study/NCT06383520"},{"label":"NCT07352345: GPC3 PET against enhanced MRI, 150 patients","url":"https://clinicaltrials.gov/study/NCT07352345"},{"label":"GPC3-targeted immunoPET translational study, EJNMMI 2026","url":"https://pubmed.ncbi.nlm.nih.gov/41688850/"}],"tags":["non-US registry","liver","China","indeterminate nodule"],"related":["ga-68"],"indications":["hcc"],"sections":[],"technologies":["immuno-pet","pet-ct","pet-mri"],"targets":["gpc3"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"non-us-registry","unmetNeed":"When a nodule in a cirrhotic liver is categorised LR-3 or LR-4, no test says whether it is cancer now, and the default is three to six months of serial imaging in a disease where delay costs the chance of curative treatment.","useCase":"A hepatologist or liver multidisciplinary team would scan the indeterminate nodule, or the patient with a rising suspicion and a normal alpha-fetoprotein, to decide immediately between ablation, resection, transplant listing and surveillance, rather than waiting for interval growth.","hypothesis":"A GPC3-directed PET agent will classify LR-3 and LR-4 liver observations correctly enough to replace the interval-growth wait, because the target is present in 70 to 80% of hepatocellular carcinomas and effectively absent from normal liver and benign lesions.","rationale":"The target contrast is the strongest part of the case: overexpression in 70 to 80% of tumours against virtual absence in normal adult liver and benign hepatic lesions, and published tumour-to-liver ratios averaging 8.3. Multiple independent groups have already imaged patients safely, one agent has detected roughly 1 cm intrahepatic metastases that MRI missed, and a registered head-to-head against enhanced MRI at 150 patients is the right comparator study. The pathology-referenced sensitivity figures from Wuhan, 90.63% with 100% specificity in one cut, are conference-level and need peer-reviewed publication before they can be relied on.","test":"A prospective study restricted to LI-RADS LR-3 and LR-4 observations, imaging each with a GPC3 tracer and following every patient to a definitive diagnosis by histology or 12-month imaging, with the primary endpoint being the proportion of indeterminate nodules correctly reclassified and the time to definitive management compared with the surveillance default. The registered 150-patient head-to-head against enhanced MRI is close to this design.","maturity":"early-clinical","verdict":"standalone-only","mostAdvanced":"[68Ga]Ga-RAYZ-8009 (RayzeBio, Bristol Myers Squibb) with a 24-patient first-in-human series in the Netherlands and Germany; the deepest programme is 68Ga-XH06 at Wuhan Union Hospital, registered as NCT06383520 at 100 patients with a 150-patient head-to-head against MRI registered as NCT07352345.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"Glypican-3 is a cell-surface heparan sulfate proteoglycan overexpressed in 70 to 80% of hepatocellular carcinomas yet virtually absent in normal adult liver and benign hepatic lesions.","source":"Filippi et al., Cancers 2025","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12292357/","weighted":true},{"domain":"clinical-evidence","state":"moderate","why":"A 24-patient first-in-human series, a 64-patient investigator-initiated cohort in India, a peer-reviewed 5-patient and 8-patient Chinese series, and registered Chinese studies of 100 and 150 patients; none is registrational.","source":"Poot et al., J Nucl Med 2024; NCT06383520","url":"https://clinicaltrials.gov/study/NCT06383520","weighted":true},{"domain":"diagnostic-performance","state":"moderate","why":"Tumour-to-liver ratio averaged 8.3 at about one hour in the first-in-human series; conference cohorts report sensitivity 90.63% with specificity 100% in 36 patients and 91.7% with 83.3% in 30, both against pathology and both unpublished in full.","source":"SNMMI 2025 press release and J Nucl Med supplement","url":"https://snmmi.org/Web/Web/News/Articles/ImmunoPET-Tracer-Enhances-Early-Detection-of-Liver-Cancer.aspx","weighted":true},{"domain":"safety-dosimetry","state":"thin","why":"No adverse events reported across the published cohorts, but no dosimetry in mSv or cGy/MBq was found for any of the newer gallium-68 GPC3 probes."},{"domain":"regulatory-path","state":"thin","why":"No GPC3-targeted imaging agent has received FDA, EMA or NMPA marketing approval, and no filing has been identified in any jurisdiction.","source":"Research review of approvals","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12292357/"}],"flags":[{"category":"technical","flag":"amber","why":"The Chinese lead is an antibody-fragment immunoPET agent and the Western lead a synthetic peptide; both image within about an hour, but liver background is the hardest part of this anatomy and the constructs differ in kinetics."},{"category":"unmet-need","flag":"green","why":"31% of LR-3 and 64% of LR-4 observations prove to be cancer, and the alternative to a decisive test is months of watching."},{"category":"ip","flag":"amber","why":"The peptide lead sits inside Bristol Myers Squibb after the RayzeBio acquisition and the antibody-fragment lead with a Chinese academic hospital; several other constructs are in early trials."},{"category":"commercial","flag":"green","why":"Standalone: the scan resolves a management dilemma by itself, in a disease that is a leading cause of cancer death worldwide, with the largest patient population in China."},{"category":"isotope","flag":"green","why":"Gallium-68 across all the leading agents."},{"category":"competition","flag":"amber","why":"At least five separate programmes have human data, split between Western peptide and Chinese antibody-fragment approaches, and none is close to filing."}],"competition":[{"name":"RayzeBio (Bristol Myers Squibb)","what":"[68Ga]Ga-RAYZ-8009, 24-patient first-in-human series in the Netherlands and Germany, no adverse events, mean tumour-to-liver ratio 8.3.","stage":"first-in-human","url":"https://pubmed.ncbi.nlm.nih.gov/39362766/"},{"name":"Union Hospital, Tongji Medical College (Wuhan)","what":"68Ga-XH06 immunoPET: NCT06383520 at 100 patients estimated, a registered 150-patient head-to-head against enhanced MRI, and published pilots of 5 and 8 patients.","stage":"early phase 1, recruiting","url":"https://clinicaltrials.gov/study/NCT06383520"},{"name":"All India Institute of Medical Sciences","what":"[68Ga]Ga-RYZ-GPC3 in 64 patients, with 92% showing at least one positive lesion.","stage":"investigator-initiated","url":"https://aacrjournals.org/cancerres/article/84/6_Supplement/2585/740458/"},{"name":"First Affiliated Hospital of Xiamen University","what":"68Ga-GPC3 PET/CT against contrast-enhanced MRI, 40 patients estimated, recruiting.","stage":"recruiting","url":"https://clinicaltrials.gov/study/NCT07677774"}],"differentiation":"Alpha-fetoprotein misses a substantial share of hepatocellular carcinoma and does not localise; contrast-enhanced MRI is the incumbent and is exactly what leaves LR-3 and LR-4 undecided; biopsy of a small nodule in a cirrhotic liver carries bleeding and seeding risk and is often deferred. A GPC3 tracer competes with the decision to wait.","metrics":[{"label":"Proportion of LI-RADS observations that prove to be hepatocellular carcinoma","value":"31% of LR-3 and 64% of LR-4","source":"Cerny et al., Radiology 2023","url":"https://pubs.rsna.org/doi/full/10.1148/radiol.222801"},{"label":"Hepatocellular carcinomas overexpressing glypican-3","value":"70 to 80%","source":"Filippi et al., Cancers 2025","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12292357/"},{"label":"Patients in the first-in-human [68Ga]Ga-RAYZ-8009 series","value":"24, no adverse events","source":"Poot et al., J Nucl Med 2024","url":"https://pubmed.ncbi.nlm.nih.gov/39362766/"},{"label":"Sensitivity and specificity of 68Ga-XH06 against pathology in the 36-patient conference cohort","value":"90.63% and 100%","source":"SNMMI 2025 abstract 252173, reported in a society press release","url":"https://snmmi.org/Web/Web/News/Articles/ImmunoPET-Tracer-Enhances-Early-Detection-of-Liver-Cancer.aspx"}],"risks":["The strongest accuracy figures are conference abstracts from overlapping cohorts at one hospital, and the exact patient overlap between the 5, 8, 30 and 36-patient reports is not stated in any source.","Around 20 to 30% of hepatocellular carcinomas do not overexpress glypican-3, so a negative scan cannot exclude cancer and the test would have to be positioned as a rule-in test only.","No dosimetry has been published for the newer gallium-68 constructs."],"watch":["Results from the registered 150-patient head-to-head against enhanced MRI, which is the study that would establish a clinical claim.","Whether Bristol Myers Squibb advances RAYZ-8009 beyond a case series, which would signal industry conviction.","Peer-reviewed publication of the 30 and 36-patient Wuhan cohorts, which currently exist only as conference abstracts."]},{"id":"opp-grpr-psma-negative-prostate","kind":"opportunity","name":"GRPR imaging when the PSMA scan is negative","aka":["GRPR PET","bombesin receptor imaging"],"tldr":"Prostate cancer imaging and treatment both rely on one protein, PSMA. In a minority of men the tumour does not carry it, and for those men a negative scan is a dead end. A second receptor, GRPR, is the best-studied alternative, and the honest reading of the head-to-head studies is that it finds fewer lesions overall but different ones.","summary":"PSMA has become the single axis of prostate cancer molecular imaging and radioligand therapy, which means the patient whose tumour does not express it has nowhere to go. The published estimates of how large that group is vary by how it is measured: around 5 to 10% of primary tumours are PSMA-negative on immunohistochemistry and around 10% are negative on PSMA PET despite a high PSA, while a commentary puts the figure at 15 to 25% of metastatic castration-resistant patients whose tumours do not significantly express PSMA.\n\nGRPR is the most clinically mature alternative. 68Ga-RM2 has a completed phase 2/3 imaging trial published in Lancet Oncology in 2024: of 209 men screened, 100 were analysed, and RM2 PET-MRI was positive in 69% against 40% for MRI alone, with no grade 1 or worse events. But the head-to-head studies are not a story of superiority. At Stanford, in 50 patients imaged with both, PSMA-directed tracers found 36 extra lesions in 13 patients while RM2 found 7 extra in 4 patients. In a Chilean mCRPC cohort of 17 patients referred for radioligand therapy, PSMA detected 23% more lesions, though in 4 of 17 the two distributions were comparable. A Bordeaux study found the two discordant in 18.8% of lesions, with RM2 better at low-ISUP tumours and PSMA better at clinically significant ones.\n\nThat is the shape of the real opportunity: not a replacement for PSMA PET but a second-look agent for the specific patient in whom PSMA imaging has failed, and a selection test for GRPR-directed therapy. 177Lu-NeoB from Advanced Accelerator Applications has completed phase 1 in NeoRay with a maximum tolerated dose of 9.25 GBq in 17 patients, and 177Lu-RM2 has first-in-human dosimetry in 4 mCRPC patients selected precisely because they had insufficient PSMA expression.","asOf":"2026-09-23","links":[{"label":"68Ga-RM2 phase 2/3, Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38423030/"},{"label":"68Ga-RM2 against PSMA tracers head to head, J Nucl Med 2021","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8612333/"},{"label":"177Lu-RM2 first-in-human dosimetry in PSMA-insufficient patients","url":"https://pubmed.ncbi.nlm.nih.gov/31482426/"},{"label":"NCT03872778: NeoRay, 177Lu-NeoB","url":"https://clinicaltrials.gov/study/NCT03872778"},{"label":"GRPR distribution in cancer, J Nucl Med 2020","url":"https://jnm.snmjournals.org/content/61/6/792"}],"tags":["unmet need first","prostate","PSMA-negative","second-look imaging"],"related":["ga-68","lu-177"],"indications":["prostate-mcrpc","prostate-bcr"],"sections":[],"technologies":["psma-pet","pet-ct","radioligand-therapy","peptide-drug-conjugate"],"targets":["grpr","psma"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"unmet-need-first","unmetNeed":"When a man with clinically obvious prostate cancer has a negative or low-uptake PSMA PET, nothing tells his clinician whether the disease is genuinely small-volume, PSMA-negative but targetable through another receptor, or dedifferentiated and beyond either.","useCase":"A prostate multidisciplinary team would order a GRPR scan as a second look after a negative or discordant PSMA PET in a man whose PSA says the disease is there, and as the selection test before GRPR-directed radioligand therapy in a patient who has exhausted PSMA-directed options.","hypothesis":"In the subgroup defined by a negative or low-uptake PSMA PET, GRPR imaging will identify disease that PSMA imaging missed at a rate high enough to change management, even though in unselected patients it detects fewer lesions than PSMA imaging does.","rationale":"GRPR overexpression has been reported in 63 to 100% of prostate cancers, and the receptor is inversely related to PSMA in part of the disease, which is why the first patients treated with 177Lu-RM2 were chosen for insufficient PSMA expression. The imaging agent has the largest dataset of any non-PSMA prostate tracer, including a completed phase 2/3 trial, and the therapeutic pair exists with a defined phase 2 dose. The lesion-level studies that look unfavourable to GRPR were all run in unselected patients, which is the wrong population for this hypothesis.","test":"A prospective study enrolling only men with a negative or equivocal PSMA PET and biochemical or clinical evidence of disease, imaging them with a GRPR tracer, with histology or subsequent conventional imaging as the truth standard, and reporting the proportion in whom a management-changing lesion was found. Enrolment on the PSMA-negative criterion is the whole design; the existing unselected head-to-heads have already answered the other question.","maturity":"being-tested-at-scale","verdict":"standalone-and-companion","mostAdvanced":"68Ga-RM2 for imaging, with a completed phase 2/3 trial (NCT02624518, 100 patients analysed) published in Lancet Oncology 2024; on the therapy side 177Lu-NeoB from Advanced Accelerator Applications, phase 1 complete in NeoRay (NCT03872778) with a maximum tolerated dose of 9.25 GBq.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"GRPR overexpression has been reported in 63 to 100% of prostate cancers, and preclinical work found high 177Lu-NeoB binding in PSMA-negative castration-resistant samples, which is the inverse relationship the whole case depends on.","source":"Frontiers in Oncology 2023 review","url":"https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1199432/full","weighted":true},{"domain":"clinical-evidence","state":"strong","why":"A completed phase 2/3 imaging trial of 100 analysed patients published in Lancet Oncology, plus three published head-to-head comparisons against PSMA tracers and a phase 1 therapy dataset.","source":"Duan et al., Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38423030/","weighted":true},{"domain":"diagnostic-performance","state":"moderate","why":"68Ga-RM2 PET-MRI was positive in 69% of patients against 40% for MRI alone, but against PSMA tracers it detected fewer lesions: 7 extra in 4 patients versus 36 extra in 13 patients across 50 men imaged with both.","source":"Baratto et al., J Nucl Med 2021","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8612333/","weighted":true},{"domain":"safety-dosimetry","state":"strong","why":"No grade 1 or worse events were reported in the 100-patient imaging trial; on the therapy side mean absorbed dose was 1.08 plus or minus 0.44 Gy/GBq in the pancreas and 6.20 plus or minus 3.00 Gy/GBq in tumour lesions, with no side effects observed in four treated patients.","source":"Kurth et al., EJNMMI 2020","url":"https://pubmed.ncbi.nlm.nih.gov/31482426/"},{"domain":"regulatory-path","state":"moderate","why":"Receptor-targeted PET has an accepted non-inferiority route: NETSPOT was approved in June 2016 on non-inferiority of performance characteristics against OctreoScan, without an advisory committee. No GRPR imaging agent has been filed anywhere.","source":"FDA approval package, NETSPOT","url":"https://www.accessdata.fda.gov/drugsatfda_docs/nda/2016/208547Orig1s000Approv.pdf"}],"flags":[{"category":"technical","flag":"green","why":"Gallium-68 labelled antagonist peptides with same-day imaging and a published clean safety record; the chemistry is not the problem here."},{"category":"unmet-need","flag":"green","why":"A PSMA-negative scan currently ends the pathway, and the population is somewhere between 10% on PET and a reported 15 to 25% of metastatic castration-resistant disease."},{"category":"ip","flag":"amber","why":"RM2 originated at Bayer and is developed academically at Stanford; NeoB belongs to Advanced Accelerator Applications; a new entrant would need its own antagonist scaffold."},{"category":"commercial","flag":"amber","why":"Standalone as a second-look scan and a companion for GRPR therapy, but the addressable group is defined by another test's failure, which makes volume a function of PSMA PET throughput."},{"category":"isotope","flag":"green","why":"Gallium-68 for imaging and lutetium-177 for therapy; both established supply chains."},{"category":"competition","flag":"amber","why":"Novartis through Advanced Accelerator Applications holds the most advanced therapy and its companion tracer, so the therapeutic pairing is largely taken."}],"competition":[{"name":"Stanford University","what":"68Ga-RM2, completed phase 2/3 imaging trial in biochemical recurrence, 100 patients analysed, published in Lancet Oncology 2024.","stage":"phase 2/3 complete","url":"https://clinicaltrials.gov/study/NCT02624518"},{"name":"Advanced Accelerator Applications (Novartis)","what":"177Lu-NeoB with its 68Ga-NeoB companion; NeoRay phase 1 complete, maximum tolerated dose 9.25 GBq, 35-patient target enrolment across 18 sites in 6 countries.","stage":"phase 1/2a","url":"https://clinicaltrials.gov/study/NCT03872778"},{"name":"Rostock University Medical Center","what":"177Lu-RM2 and 177Lu-AMTG first-in-human dosimetry, four patients treated after screening 35 with 68Ga-RM2 PET/CT.","stage":"first-in-human","url":"https://pubmed.ncbi.nlm.nih.gov/31482426/"}],"differentiation":"The percentage of PSMA-negative tumour area on immunohistochemistry is reported as an independent prognostic factor but is not a clinical decision tool, and no ctDNA or blood test identifies a GRPR-positive compartment. Imaging is the only way to establish target expression at every lesion at once, which is exactly what a patient with a discordant PSMA scan needs.","metrics":[{"label":"68Ga-RM2 PET-MRI positive rate against MRI alone in biochemical recurrence","value":"69% against 40% of 100 patients","source":"Duan et al., Lancet Oncology 2024","url":"https://pubmed.ncbi.nlm.nih.gov/38423030/"},{"label":"Extra lesions found by each tracer in 50 patients imaged with both","value":"PSMA 36 lesions in 13 patients; RM2 7 lesions in 4 patients","source":"Baratto et al., J Nucl Med 2021","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8612333/"},{"label":"Primary prostate cancers negative on PSMA PET despite high PSA","value":"around 10%","source":"Published review","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC7255040/"},{"label":"Maximum tolerated dose of 177Lu-NeoB in phase 1","value":"9.25 GBq","source":"Phase 1 NeoRay report","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12866383/"}],"risks":["In unselected patients GRPR imaging detects fewer lesions than PSMA imaging, so the agent only makes sense in a narrow, test-defined subgroup and must be trialled that way.","There is no agreed definition of a PSMA-negative scan, so the enrolment criterion for the pivotal study has to be constructed before the study can run.","The most advanced therapeutic pairing sits inside Novartis, which limits partnering options for an independent imaging agent."],"watch":["Any trial that enrols on PSMA-negativity rather than on known measurable disease, which would be the first real test of this hypothesis.","Phase 2a efficacy from NeoRay in the prostate cohort, which determines whether a companion diagnostic has a therapy to serve.","Whether the 15 to 25% mCRPC figure is ever established by a primary dataset rather than commentary; the size of the opportunity turns on it."]},{"id":"opp-her3-imaging-crossover","kind":"opportunity","name":"HER3 imaging, and why three tracers stalled","aka":["HER3 PET"],"tldr":"HER3 sits on most lung cancers and there are drugs aimed at it, so a scan showing which tumours carry it looks obvious. Three attempts were made and all three stopped, largely because the drug's own trials could not show that how much HER3 a tumour has predicts whether the drug works.","summary":"HER3 is the textbook crossover case: expressed in around 80% of non-small cell lung cancers, targeted by patritumab deruxtecan and other antibody-drug conjugates, with no radioligand in routine use. Three antibody PET tracers were built (64Cu-patritumab, 89Zr-GSK2849330, 89Zr-lumretuzumab) and all three belong to drug programmes that lost momentum or were discontinued. Only one HER3 imaging trial is currently recruiting: 89Zr-patritumab deruxtecan at the Netherlands Cancer Institute with Daiichi Sankyo as collaborator, 16 patients, on the explicit rationale that HER3 expression can be assessed non-invasively including at sites that are difficult to biopsy.\n\nThe honest problem is not the tracer. Patritumab deruxtecan's own biomarker analyses report no relationship between efficacy and HER3 protein expression by immunohistochemistry, and the SOLTI TOT-HER3 work found activity across a wide range of ERBB3 mRNA and HER3 protein levels, suggesting limited predictive value. One published tracer study could determine no correlation between tumour uptake and ex-vivo immunohistochemistry. The drug itself received a complete response letter in June 2024 on a third-party manufacturing finding, and the BLA was withdrawn in May 2025 after HERTHENA-Lung02 missed its overall survival endpoint.\n\nThis record exists as a worked negative: the crossover lens will keep producing targets like this, and the discipline it needs is to ask whether expression predicts benefit before assuming a companion diagnostic has a market.","asOf":"2026-09-23","links":[{"label":"NCT06222489: 89Zr-patritumab deruxtecan PET/CT","url":"https://clinicaltrials.gov/study/NCT06222489"},{"label":"No relationship between HER3-DXd efficacy and HER3 immunohistochemistry, Nature Communications 2024","url":"https://www.nature.com/articles/s41467-024-50056-y"},{"label":"Complete response letter for patritumab deruxtecan, June 2024","url":"https://daiichisankyo.us/press-releases/-/article/patritumab-deruxtecan-bla-submission-receives-complete-response-letter-from-fda-due-to-inspection-findings-at-third-party-manufacturer"},{"label":"No validated HER3 immunohistochemistry assays or thresholds (review)","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12758208/"},{"label":"Fluoroestradiol F-18 label, the receptor-imaging precedent","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/212155s000lbl.pdf"}],"tags":["target crossover","worked negative","lung","companion diagnostic"],"related":["zr-89","cu-64"],"indications":["nsclc"],"sections":[],"technologies":["immuno-pet","pet-ct"],"targets":["her3"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"target-crossover","unmetNeed":"There is no non-invasive way to measure HER3 across all of a patient's disease, including its rise after EGFR-inhibitor therapy, but it is also not established that knowing HER3 expression changes who benefits from a HER3-directed drug.","useCase":"In its plausible form, a HER3 tracer is a pharmacodynamic and trial-enrichment tool rather than a clinical test: measuring target engagement and the change in HER3 after EGFR-inhibitor therapy inside a drug-development programme. A clinical selection use would require a predictive relationship that the drug's own trials have so far failed to demonstrate.","hypothesis":"Whole-body HER3 quantification will predict response to a HER3-directed antibody-drug conjugate where single-site immunohistochemistry does not, because the failure of tissue testing reflects sampling and assay variability rather than the absence of a true dose-response relationship.","rationale":"HER3 is expressed in the great majority of lung cancers and rises after EGFR-inhibitor treatment, so there is a real biological signal to measure, and imaging is the only way to measure it everywhere at once. Against that, the published record is discouraging in a specific and informative way: there are no validated HER3 immunohistochemistry assays and no standardised scoring thresholds, the sponsor found no relationship between expression and efficacy, and one tracer study could not correlate uptake with tissue staining. The hypothesis above is testable but currently unsupported.","test":"A trial-embedded study in patients receiving a HER3-directed antibody-drug conjugate, imaging before treatment and after one cycle, powered to relate baseline tracer uptake and its change to objective response. The question it must answer is not whether the tracer binds HER3 but whether tracer uptake separates responders from non-responders where immunohistochemistry did not.","maturity":"early-clinical","verdict":"companion-only","mostAdvanced":"89Zr-patritumab deruxtecan PET/CT at the Netherlands Cancer Institute with Daiichi Sankyo, 16 patients, recruiting under NCT06222489; the only active HER3 imaging trial found.","dueDiligence":[{"domain":"target-biology","state":"strong","why":"HER3 has been reported in 83% of non-small cell lung cancers and estimated at up to 80% depending on stage; overexpression occurred in 42% of a 45-patient cohort, more often than HER2.","source":"Published NSCLC series","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12393064/"},{"domain":"clinical-evidence","state":"thin","why":"Three antibody tracers were built and all sit in stalled or discontinued drug programmes; one active trial of 16 patients is recruiting. No imaging agent has reported a relationship to outcome.","source":"NCT06222489","url":"https://clinicaltrials.gov/study/NCT06222489"},{"domain":"diagnostic-performance","state":"none","why":"For 64Cu-patritumab, no correlation between tumour uptake and ex-vivo immunohistochemistry could be determined, and the drug's own analyses report no relationship between HER3 protein expression and efficacy.","source":"Sponsor biomarker analyses and tracer report","url":"https://www.nature.com/articles/s41467-024-50056-y","weighted":true},{"domain":"safety-dosimetry","state":"thin","why":"Antibody-based HER3 tracers have been given to humans without reported safety signals in small series, but no dosimetry figure worth quoting has been published for the current agent."},{"domain":"regulatory-path","state":"moderate","why":"Receptor-status PET has a precedent: fluoroestradiol F-18 was approved in May 2020 as an adjunct to biopsy for detecting oestrogen-receptor-positive lesions, judged on reader concordance against biopsy rather than a drug-selection claim.","source":"FDA review, fluoroestradiol F-18","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/212155s000lbl.pdf"}],"flags":[{"category":"technical","flag":"amber","why":"Antibody kinetics again: the only active agent is a zirconium-89 labelled antibody-drug conjugate, which images days after injection."},{"category":"unmet-need","flag":"red","why":"The clinical need is unproven, not merely unmet: the sponsor's own trials found no relationship between HER3 expression and benefit, so a test that measures expression may change nothing."},{"category":"ip","flag":"red","why":"Every clinical HER3 tracer is derived from a specific therapeutic antibody owned by its sponsor, so an independent programme would need a new binder."},{"category":"commercial","flag":"red","why":"Companion-only, and the lead therapy's BLA was withdrawn in May 2025 after a failed overall-survival endpoint, so the market it would serve is not currently approved."},{"category":"isotope","flag":"amber","why":"Zirconium-89 and copper-64 are available but cyclotron-dependent and less widely distributed than gallium-68 or fluorine-18."},{"category":"competition","flag":"green","why":"Nobody is competing, which in this case reflects the weak predictive case rather than an opening."}],"competition":[{"name":"Netherlands Cancer Institute with Daiichi Sankyo","what":"89Zr-patritumab deruxtecan PET/CT, 16 patients, recruiting; the only active HER3 imaging trial found.","stage":"recruiting","url":"https://clinicaltrials.gov/study/NCT06222489"},{"name":"Historical programmes","what":"64Cu-patritumab, 89Zr-GSK2849330 and 89Zr-lumretuzumab, all attached to drug programmes that were discontinued or lost momentum.","stage":"discontinued","url":"https://apps.dtic.mil/sti/pdfs/AD1050824.pdf"}],"differentiation":"HER3 immunohistochemistry exists but is unvalidated: reviews state there are no validated assays and no standardised scoring thresholds for predicting benefit, and an mRNA alternative developed by the SOLTI group was also not predictive. Imaging would differ by sampling every lesion, but it inherits the underlying problem that no measure of HER3 has yet predicted response.","metrics":[{"label":"Non-small cell lung cancers reported to express HER3","value":"83%","source":"Published NSCLC series","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12393064/"},{"label":"Patients randomised in HERTHENA-Lung02, whose overall-survival miss preceded BLA withdrawal","value":"586","source":"HERTHENA-Lung02 reporting","url":"https://www.nature.com/articles/s41467-024-50056-y"}],"risks":["The predictive premise may simply be false: if HER3 level does not determine benefit, no measurement of it will.","The tracer is tied to a therapeutic asset whose regulatory path has already failed once.","Antibody format and isotope choice make routine delivery expensive relative to the information gained."],"watch":["Results from NCT06222489, especially any relationship between uptake and response rather than uptake and staining.","Whether any HER3 drug programme re-files and, if so, whether a selection biomarker appears on its label.","Publication of a validated, standardised HER3 tissue assay, which would either remove the need for imaging or give it a comparator worth beating."]},{"id":"opp-trop2-imaging-heterogeneity","kind":"opportunity","name":"TROP2 imaging where no tissue test is required","aka":["TROP2 PET","Trop-2 imaging"],"tldr":"Two approved breast cancer drugs work through a protein called TROP2, and neither requires any test for it before use. Tumours vary a lot in how much they carry, and a quarter of patients lose it over time, so nobody currently knows who is being treated for a target that is no longer there.","summary":"Sacituzumab govitecan and datopotamab deruxtecan are both approved TROP2-directed antibody-drug conjugates, and neither label requires a TROP2 assay. That is not because expression is irrelevant: in the ASCENT biomarker analysis, patients with high TROP2 expression had an objective response rate of 44% against 22% in the low group, with progression-free survival of 6.9 against 2.7 months. It is because the tissue test does not work well enough to gate treatment. A comparison of three immunohistochemistry assays found only fair-to-moderate concordance, there is no validated plasma or ctDNA assay, and a study of circulating tumour cells found no concordance between cell-based and tissue TROP2 status.\n\nHeterogeneity is documented in both space and time: in paired primary and brain-metastasis samples, 21.4% of cases were discordant, and in a longitudinal biopsy series 27.6% of patients showed a marked fall in TROP2 H-score between consecutive time points. Bone metastases showed lower TROP2 than other sites in a post-mortem multi-metastasis study.\n\nThe imaging programmes are Chinese, academic and moving quickly. The nanobody tracer 68Ga-MY6349 completed a 90-patient multi-tumour feasibility study and then a 73-patient breast-specific study published in Theranostics in 2026. Nobody has filed anywhere. Because no companion diagnostic exists to be displaced, an imaging agent here would not be competing with an approved assay but filling a space that both drug labels leave open.","asOf":"2026-09-23","links":[{"label":"68Ga-MY6349 in breast cancer, Theranostics 2026","url":"https://www.thno.org/v16p8117.htm"},{"label":"ASCENT TROP2 biomarker analysis","url":"https://pubmed.ncbi.nlm.nih.gov/34116144/"},{"label":"TROP2 biomarker review: no companion diagnostic, no validated plasma assay","url":"https://biomarker.onclive.com/breast-cancer/triple-negative-tnbc/biomarkers/trop2"},{"label":"Longitudinal fall in TROP2 expression during treatment","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC13379550/"},{"label":"FDA approval of datopotamab deruxtecan, January 2025","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-datopotamab-deruxtecan-dlnk-unresectable-or-metastatic-hr-positive-her2-negative-breast"}],"tags":["target crossover","breast","heterogeneity","nanobody"],"related":["ga-68"],"indications":["breast-triple-negative"],"sections":[],"technologies":["trop2-pet","immuno-pet","pet-ct"],"targets":["trop2"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"lens":"target-crossover","unmetNeed":"Neither approved TROP2 antibody-drug conjugate requires a test for TROP2, and no validated blood or tissue assay exists, so when a patient stops responding nobody can tell whether the target has been lost or the payload has failed.","useCase":"A breast oncologist would scan before starting a TROP2 antibody-drug conjugate in a patient with several metastatic sites including bone, and again at progression, to distinguish loss of target from resistance to the payload. In practice the first real use is inside trials, deciding whether target level predicts benefit well enough to justify a clinical test at all.","hypothesis":"Whole-body TROP2 quantification will predict benefit from TROP2-directed antibody-drug conjugates better than tissue immunohistochemistry, because the observed 21% primary-to-metastasis discordance and the 28% of patients with a marked longitudinal fall in expression are exactly the errors a single biopsy cannot avoid and imaging can.","rationale":"Unlike HER3, there is already a published expression-response gradient for a TROP2 drug: 44% against 22% objective response by expression level in ASCENT. The reason that gradient has not become a test is assay failure rather than absent biology, and the failures are specifically of sampling and standardisation, which is the class of problem imaging addresses. Nanobody constructs give same-day imaging, and one has already been through 90 patients across tumour types and then a 73-patient disease-specific study.","test":"A study embedded in a TROP2 antibody-drug conjugate trial: image before treatment, relate uptake to objective response and progression-free survival, and re-image at progression in a subset to measure change in target. The primary question is whether an imaging threshold separates responders better than the published immunohistochemistry cut-offs did in ASCENT.","maturity":"early-clinical","verdict":"companion-only","mostAdvanced":"68Ga-MY6349, a TROP2 nanobody tracer from Shanghai Novamab studied at Xiamen and Fudan, with a completed 90-patient multi-tumour study and a 73-patient breast-cancer study published in Theranostics in 2026.","dueDiligence":[{"domain":"target-biology","state":"moderate","why":"TROP2 is widely expressed in breast cancer but with marked intratumoral heterogeneity and discordance between primary and metastatic sites; membranous rather than cytoplasmic localisation appears to matter more than total intensity.","source":"TROP2 biomarker review","url":"https://biomarker.onclive.com/breast-cancer/triple-negative-tnbc/biomarkers/trop2","weighted":true},{"domain":"clinical-evidence","state":"moderate","why":"One nanobody tracer has a completed 90-patient feasibility study and a published 73-patient breast-specific study; all of it academic, single-country and not registrational.","source":"Theranostics 2026","url":"https://www.thno.org/v16p8117.htm"},{"domain":"diagnostic-performance","state":"thin","why":"No study relates tracer uptake to antibody-drug conjugate response. The comparator's performance is the strongest published signal: ASCENT reported 44% against 22% objective response by TROP2 expression level.","source":"ASCENT biomarker analysis","url":"https://pubmed.ncbi.nlm.nih.gov/34116144/","weighted":true},{"domain":"safety-dosimetry","state":"thin","why":"No adverse events reported in the published nanobody cohorts, but no formal dosimetry figure has been published that is worth quoting."},{"domain":"regulatory-path","state":"thin","why":"There is no TROP2 companion diagnostic to anchor a claim, and neither drug label requires testing, so an imaging agent would have to define its own indication, most plausibly as an adjunct rather than a selection gate.","source":"TROP2 biomarker review","url":"https://biomarker.onclive.com/breast-cancer/triple-negative-tnbc/biomarkers/trop2"}],"flags":[{"category":"technical","flag":"green","why":"A nanobody construct labelled with gallium-68 already images in humans with same-day kinetics, which is the format this kind of agent needs."},{"category":"unmet-need","flag":"amber","why":"Real heterogeneity and a published expression-response gradient, but both drugs are prescribed today without any test, so the clinical pull is weaker than the biology suggests."},{"category":"ip","flag":"amber","why":"The leading construct is owned by a Chinese biotech and studied with academic partners; no Western clinical programme is disclosed."},{"category":"commercial","flag":"amber","why":"Two approved drugs and expanding indications make the addressable population large, but a test that neither label requires has to earn reimbursement on its own evidence."},{"category":"isotope","flag":"green","why":"Gallium-68 on a nanobody; nothing scarce."},{"category":"competition","flag":"amber","why":"The Chinese programme is several years and roughly 160 patients ahead of anyone else."}],"competition":[{"name":"Shanghai Novamab with Xiamen and Fudan centres","what":"68Ga-MY6349 nanobody PET; completed 90-patient multi-tumour study and a published 73-patient breast-cancer study.","stage":"early clinical","url":"https://www.thno.org/v16p8117.htm"},{"name":"Gilead","what":"Sacituzumab govitecan, approved since 2020 across triple-negative and HR-positive breast cancer; no TROP2 test required.","stage":"approved","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-sacituzumab-govitecan-hziy-metastatic-triple-negative-breast-cancer"},{"name":"Daiichi Sankyo and AstraZeneca","what":"Datopotamab deruxtecan, approved January 2025 for HR-positive disease and later in triple-negative disease; no TROP2 test required.","stage":"approved","url":"https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-datopotamab-deruxtecan-dlnk-unresectable-or-metastatic-hr-positive-her2-negative-breast"}],"differentiation":"There is no approved companion diagnostic, no validated plasma or ctDNA assay, and circulating-tumour-cell TROP2 does not agree with tissue. A quantitative digital-pathology score has separated responders in lung cancer but remains investigational and has no role in breast cancer today. An imaging agent would therefore be competing against nothing, which is both the opportunity and the reason reimbursement would be hard.","metrics":[{"label":"Objective response rate, high against low TROP2 expression in ASCENT","value":"44% against 22%","source":"ASCENT biomarker analysis","url":"https://pubmed.ncbi.nlm.nih.gov/34116144/"},{"label":"Paired primary and brain-metastasis samples discordant for TROP2","value":"21.4% of 14","source":"Paired-sample immunohistochemistry study","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12531291/"},{"label":"Patients with a marked longitudinal fall in TROP2 H-score","value":"27.6%","source":"Longitudinal biopsy series","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC13379550/"},{"label":"Concordance between three TROP2 immunohistochemistry assays","value":"fair to moderate (AC2 0.35)","source":"Assay comparison study","url":"https://ngdc.cncb.ac.cn/openlb/publication/OLB-PM-40914741"}],"risks":["Neither drug label requires a test, so oncologists have no workflow reason to order a scan and payers have no reason to fund it.","If the expression-response gradient does not reproduce in the datopotamab deruxtecan datasets, the predictive premise weakens.","The leading construct is already in a second disease-specific study, so a new entrant starts well behind."],"watch":["Any published relationship between TROP2 tracer uptake and antibody-drug conjugate response, which is the missing link in the whole case.","Whether a quantitative digital-pathology score reaches the breast cancer label, which would make a tissue test the standard and box in the scan.","Registration of a TROP2 imaging trial outside China, which would be the first sign of industry interest."]}]