PSMA theranostics roadmap: antigen discovery → PSMA PET → 177Lu-PSMA-617 → earlier lines and alpha
Prostate-specific membrane antigen was found on prostate cancer cells in 1987. It took until 2020-2022 for scans and treatments that target it to reach approval, but once they did, PSMA PET and Pluvicto changed how metastatic prostate cancer is staged and treated, and the same target is now being tried earlier in the disease and with more powerful alpha particles.
Overview
Prostate-specific membrane antigen (PSMA) was first identified in 1987 when Horoszewicz and Murphy raised the monoclonal antibody 7E11-C5 against the LNCaP prostate cancer cell line; Heston and Fair's group at Memorial Sloan Kettering cloned the PSMA gene in 1993. The first PSMA-targeted imaging agent to reach approval, indium-111 capromab pendetide (ProstaScint), was approved by the FDA on 28 October 1996, but bound only an intracellular epitope and had limited clinical impact.
The modern era begins with small-molecule PSMA ligands: Eder and colleagues at the German Cancer Research Center (DKFZ) Heidelberg synthesised the gallium-68-labelled HBED-CC compound that became PSMA-11 in 2012, building on first-in-human work from 2011. It took until 1 December 2020 for the FDA to approve 68Ga-PSMA-11 (jointly, as separate applications from UCSF and UCLA), the first PSMA PET agent approved in the US, followed by the first commercially distributable PSMA PET agent, Pylarify (piflufolastat F 18), on 26 May 2021. On the therapy side, Kratochwil's Heidelberg group had already shown in 2016 that the corresponding alpha-emitting ligand, 225Ac-PSMA-617, could produce complete responses; the beta-emitting version, 177Lu-PSMA-617 (Pluvicto), was approved by the FDA on 23 March 2022 for post-chemotherapy mCRPC, based on the VISION trial (a 38% reduction in risk of death).
The label then moved earlier: on 28 March 2025 the FDA expanded Pluvicto's indication, based on the PSMAfore trial, to PSMA-positive mCRPC patients who have progressed on one androgen receptor pathway inhibitor and are considered appropriate to delay chemotherapy, removing the prior-taxane requirement and roughly tripling the eligible US population. The alpha-emitting analogue of Pluvicto, 225Ac-PSMA-617 (AAA817, Novartis), and a second alpha PSMA ligand, FPI-2265 (225Ac-PSMA-I&T, Fusion Pharmaceuticals), are both now in phase 3 programmes for patients whose disease has progressed on 177Lu-PSMA, the next planned step in the sequence.
- 1987-1996historic
PSMA discovered; first imaging agent approved
Horoszewicz, Kawinski and Murphy raise the 7E11-C5 monoclonal antibody against PSMA in 1987; Heston and Fair's group at Memorial Sloan Kettering clone the PSMA gene in 1993. The FDA approves the first PSMA-targeted imaging agent, indium-111 capromab pendetide (ProstaScint, Cytogen), on 28 October 1996, though the antibody binds an intracellular epitope and offers limited sensitivity.
- 2011-2012historic
Small-molecule PSMA ligands and first-in-human PET
The Heidelberg group at the German Cancer Research Center (DKFZ) reports first-in-human imaging with a gallium-68-labelled small-molecule PSMA inhibitor in 2011; Eder and colleagues publish the synthesis of the HBED-CC-chelated compound that becomes PSMA-11 in 2012, replacing antibody-based imaging with fast, high-contrast small-molecule PET.
- 2016historic
225Ac-PSMA-617: alpha therapy proof of concept
Kratochwil, Bruchertseifer and colleagues report complete biochemical and imaging responses with 225Ac-PSMA-617 in two heavily pretreated patients with mCRPC (J Nucl Med, 2016), the first demonstration that a PSMA-targeted alpha emitter could produce deep responses where beta therapy and other options had failed.
- 2020-2022historic
PSMA PET and Pluvicto reach approval
The FDA approves 68Ga-PSMA-11 on 1 December 2020 (UCSF and UCLA applications), the first PSMA PET agent approved in the US; Pylarify (piflufolastat F 18, Lantheus) follows on 26 May 2021 as the first commercially distributed PSMA PET agent. Pluvicto (177Lu-PSMA-617, Novartis) is approved 23 March 2022 for PSMA-positive mCRPC after androgen receptor pathway inhibition and taxane chemotherapy, based on VISION (38% reduction in risk of death), the first FDA-approved targeted radioligand therapy for prostate cancer.
- 2025current
Pluvicto moves to an earlier line
The FDA expands the Pluvicto label on 28 March 2025, based on the PSMAfore trial, to adults with PSMA-positive mCRPC who have progressed on at least one androgen receptor pathway inhibitor and are considered appropriate to delay taxane chemotherapy, removing the prior-taxane requirement and roughly tripling the eligible US patient population.
- 2024-2028emerging
Alpha-emitting PSMA ligands after 177Lu-PSMA
Two alpha-emitting PSMA ligands are in phase 2/3 development for patients progressing after 177Lu-PSMA therapy: FPI-2265 (225Ac-PSMA-I&T, Fusion Pharmaceuticals/AstraZeneca) in AlphaBreak, and AAA817 (225Ac-PSMA-617, Novartis) in a phase 3 programme including PSMAcTION (NCT06780670) and a combination trial with an androgen receptor pathway inhibitor (NCT06855277).
- 2028+speculative
Speculative: PSMA-directed therapy at diagnosis
Ideas under discussion include PSMA-PET-guided metastasis-directed therapy as a curative strategy in oligorecurrent disease, alpha-emitting PSMA therapy at first metastatic diagnosis rather than after multiple prior lines, and using PSMA PET tumour volume as a formally qualified imaging biomarker for trials.
Probability ranges are named estimates that the claim is borne out on roughly a five-year horizon. They are meant to be argued with: propose a revision with your name and reasoning via a pull request to src/data/confidence.ts.
What to watch
Readouts, decisions and registry completion dates ahead. Each date is quoted from its source, not inferred; a missing date means no source states one.
- Primary Completion (Estimated): 2028-09-29
- Primary completion date: Jun 27, 2028 (Anticipated)
- Estimated Completion: July 23, 2026AlphaBreak (FPI-2265) phase 2 primary completion source
Story
topPSMA discovered; first imaging agent approved
Horoszewicz, Kawinski and Murphy raise the 7E11-C5 monoclonal antibody against PSMA in 1987; Heston and Fair's group at Memorial Sloan Kettering clone the PSMA gene in 1993. The FDA approves the first PSMA-targeted imaging agent, indium-111 capromab pendetide (ProstaScint, Cytogen), on 28 October 1996, though the antibody binds an intracellular epitope and offers limited sensitivity.
Small-molecule PSMA ligands and first-in-human PET
The Heidelberg group at the German Cancer Research Center (DKFZ) reports first-in-human imaging with a gallium-68-labelled small-molecule PSMA inhibitor in 2011; Eder and colleagues publish the synthesis of the HBED-CC-chelated compound that becomes PSMA-11 in 2012, replacing antibody-based imaging with fast, high-contrast small-molecule PET.
A prostate-cancer-specific PET scan that finds spread far earlier than CT or bone scan, and tells you whether a matched radioactive drug will work.
Nuclear medicine physician whose group invented FAPI PET tracers and pioneered PSMA and FAP radioligand therapy.
225Ac-PSMA-617: alpha therapy proof of concept
Kratochwil, Bruchertseifer and colleagues report complete biochemical and imaging responses with 225Ac-PSMA-617 in two heavily pretreated patients with mCRPC (J Nucl Med, 2016), the first demonstration that a PSMA-targeted alpha emitter could produce deep responses where beta therapy and other options had failed.
PSMA PET and Pluvicto reach approval
The FDA approves 68Ga-PSMA-11 on 1 December 2020 (UCSF and UCLA applications), the first PSMA PET agent approved in the US; Pylarify (piflufolastat F 18, Lantheus) follows on 26 May 2021 as the first commercially distributed PSMA PET agent. Pluvicto (177Lu-PSMA-617, Novartis) is approved 23 March 2022 for PSMA-positive mCRPC after androgen receptor pathway inhibition and taxane chemotherapy, based on VISION (38% reduction in risk of death), the first FDA-approved targeted radioligand therapy for prostate cancer.
Gallium-68 PSMA-11 was the first PSMA PET tracer approved in the US (2020), and is made on site from a generator or cyclotron.
Piflufolastat F-18 (Pylarify) is the leading PSMA PET tracer for prostate cancer, with a new formulation approved in March 2026.
A radioactive drug that seeks out PSMA on prostate cancer cells; the best-selling radiopharmaceutical ever.
VISION was the trial that established radioligand therapy in prostate cancer.
A radioactive drug that homes to the PSMA protein on prostate cancer cells helped men with heavily pretreated metastatic prostate cancer live about four months longer, launching radioligand therapy as a mainstream treatment.
Pluvicto moves to an earlier line
The FDA expands the Pluvicto label on 28 March 2025, based on the PSMAfore trial, to adults with PSMA-positive mCRPC who have progressed on at least one androgen receptor pathway inhibitor and are considered appropriate to delay taxane chemotherapy, removing the prior-taxane requirement and roughly tripling the eligible US patient population.
Alpha-emitting PSMA ligands after 177Lu-PSMA
Two alpha-emitting PSMA ligands are in phase 2/3 development for patients progressing after 177Lu-PSMA therapy: FPI-2265 (225Ac-PSMA-I&T, Fusion Pharmaceuticals/AstraZeneca) in AlphaBreak, and AAA817 (225Ac-PSMA-617, Novartis) in a phase 3 programme including PSMAcTION (NCT06780670) and a combination trial with an androgen receptor pathway inhibitor (NCT06855277).
The actinium-225 PSMA trials that will help decide whether alpha-emitting PSMA drugs become the next step after Pluvicto.
Alpha-emitting PSMA drugs that produce responses even after Pluvicto fails, held back mainly by isotope supply.
Speculative: PSMA-directed therapy at diagnosis
Ideas under discussion include PSMA-PET-guided metastasis-directed therapy as a curative strategy in oligorecurrent disease, alpha-emitting PSMA therapy at first metastatic diagnosis rather than after multiple prior lines, and using PSMA PET tumour volume as a formally qualified imaging biomarker for trials.
When PSMA PET finds only a few spots after surgery, zap each spot with focused radiation and delay or avoid lifelong hormone therapy.
If Pluvicto helps at first diagnosis, an alpha version might do more against microscopic disease, when tumour burden is smallest.
PSMA scans could measure prostate cancer burden and response far better than PSA, but no one has done the standardisation work to make the measurement trustworthy across scanners.
Men with metastatic castration-resistant prostate cancer that has progressed after hormonal therapy and chemotherapy, and whose tumours show PSMA on a PET scan, can now receive lutetium-PSMA, which extends life, controls pain and is usually better tolerated than further chemotherapy. It has established a new treatment class in which a scan decides who gets the matching radioactive drug, and it is now being tested earlier in the disease (PSMAfore, PSMAddition).
PSMA PET-CT is the preferred staging investigation for high-risk prostate cancer and for biochemical recurrence, though most treatment trials were designed with conventional imaging.
Similar pages
not linked directly; found by shared links- Pairing177Lu-PSMA-617 then 225Ac-PSMA rescue therapy
Shares Clemens Kratochwil, Uwe Haberkorn, Actinium-225 PSMA agents, Metastatic castration-resistant prostate cancer.
- TermPSMA-RADS (PSMA reporting and data system)
Shares Piflufolastat F-18 / Pylarify TruVu, Gallium-68 gozetotide (PSMA-11), VISION, Metastatic castration-resistant prostate cancer.
- Key paper225Ac-PSMA-617 for PSMA-targeted alpha-radiation therapy of metastatic castration-resistant prostate cancer
Shares Clemens Kratochwil, Uwe Haberkorn, Actinium-225 PSMA agents, Metastatic castration-resistant prostate cancer.
- PairingPSMA PET → PSMA radioligand therapy
Shares Qualify PSMA PET tumour volume as a validated imaging biomarker, Piflufolastat F-18 / Pylarify TruVu, VISION: lutetium-177 PSMA-617 radioligand therapy extends survival in advanced prostate cancer, PSMA.
- Key paperTheraP: [177Lu]Lu-PSMA-617 versus cabazitaxel in metastatic castration-resistant prostate cancer
Shares Michael Hofman, Michael J. Morris, Lutetium-177 radioligand therapy, VISION.
- PairingDocetaxel (taxane chemotherapy) then 177Lu-PSMA-617
Shares Michael J. Morris, PSMAfore, VISION: lutetium-177 PSMA-617 radioligand therapy extends survival in advanced prostate cancer, VISION.
- TermSalivary gland toxicity (xerostomia) from PSMA radioligand therapy
Shares 177Lu-PSMA-I&T, PSMAfore, VISION, Metastatic castration-resistant prostate cancer.
- Key paperLuPSMA trial: single-arm phase 2 study of 177Lu-PSMA-617 in metastatic castration-resistant prostate cancer
Shares Michael Hofman, Lutetium-177 radioligand therapy, VISION, Metastatic castration-resistant prostate cancer.