# PHERGain

Source: https://nuclide.cc/trials/phergain/  
Nuclide record `phergain` (Trial). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

Using an early PET scan to spot responders let a third of women be cured of HER2-positive breast cancer without any chemotherapy.

## Summary

PET responders after 2 cycles continued antibodies alone; those achieving pCR (37.9% of the arm) skipped chemotherapy entirely. 3-year iDFS 95.4% in the PET-adapted arm, meeting its co-primary endpoint. Discussed at ESMO Breast 2026 as the model for imaging-guided de-escalation; a phase 3 (PHERGain-2) is underway.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-07
- Registry id: NCT03161353
- Phase: 2
- Setting: HER2+ early breast cancer: chemotherapy-free trastuzumab + pertuzumab with early 18F-FDG PET response assessment to decide whether chemotherapy is needed
- Sponsor: MEDSIR
- Enrolled: 377
- Result: 3-year iDFS 95.4% in the PET-adapted arm; ~1 in 3 spared chemotherapy.
- Outcomes: 3-year invasive disease-free survival (PET-adapted arm): PET-adapted HP ± chemotherapy 95.4%
- Replication: Consistent with WSG-ADAPT HER2+/HR- (pCR-guided de-escalation); phase 3 confirmation pending.

## Sources

- ClinicalTrials.gov NCT03161353: https://clinicaltrials.gov/study/NCT03161353

## Connected records

- indications: [HER2-positive breast cancer](https://nuclide.cc/indications/breast-her2-positive/)
- technologies: [FDG PET](https://nuclide.cc/technologies/fdg-pet/)

---
JSON: https://nuclide.cc/api/v1/entities/phergain.json