# Palbociclib for Hormone-Receptor-Positive, HER2-Positive Advanced Breast Cancer

Source: https://onco.cc/key-papers/paper-patina-n-engl-j-med-2026/  
OnCo record `paper-patina-n-engl-j-med-2026` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Published report from the PATINA trial registered as NCT02947685, in New England Journal of Medicine (2026), chosen as the most cited paper whose own text cites the registry id.

## Summary

Background: Dual anti-human epidermal growth factor receptor 2 (HER2) therapy plus chemotherapy followed by maintenance treatment with HER2-targeted and endocrine therapies is standard first-line treatment for hormone-receptor-positive, HER2-positive metastatic breast cancer. On the basis of preclinical and clinical data, the addition of palbociclib (a selective inhibitor of cyclin-dependent kinases 4 and 6) may overcome resistance to both endocrine and HER2-directed therapies.

Methods: In this phase 3, open-label, randomized trial, we enrolled patients with hormone-receptor-positive, HER2-positive metastatic breast cancer who did not have disease progression after four to eight cycles of chemotherapy plus HER2-targeted therapy. Patients were randomly assigned in a 1:1 ratio to receive maintenance HER2-targeted and endocrine therapies with or without palbociclib. The primary end point was investigator-assessed progression-free survival. Secondary end points included the objective response, clinical benefit, safety, and overall survival.

Results: A total of 518 patients underwent randomization: 261 were assigned to receive palbociclib and 257 to receive standard therapy. At a median follow-up of 53.5 months, patients in the palbociclib group had significantly longer progression-free survival than those in the standard-therapy group (median duration, 44.3 months vs. 29.1 months; hazard ratio for disease progression or death, 0.75; 95% confidence interval, 0.59 to 0.96; two-sided P = 0.02). Grade 3 and 4 adverse events, predominantly from neutropenia, occurred in 79.7% and 10.0% of the patients, respectively, in the palbociclib group, as compared with 30.6% and 3.6% of the patients, respectively, in the standard-therapy group.

Conclusions: The addition of palbociclib to maintenance anti-HER2 and endocrine therapies led to a significant improvement in progression-free survival over standard therapy, with increased toxic effects, mainly neutropenia. (Funded by Pfizer and others; PATINA ClinicalTrials.gov number, NCT02947685.).

Indexed on Europe PMC as PubMed record 41604639 (DOI 10.1056/nejmoa2511218). Its abstract cites the registry id NCT02947685, which is how it was matched to this trial; no figure has been checked by an editor.

## Fields

- Kind: Key paper
- Last checked: 2026-09-22
- Tags: europepmc-ingest
- Journal: New England Journal of Medicine
- Year: 2026
- DOI: 10.1056/nejmoa2511218
- Authors: Metzger O, Mandrekar S, Goel S, et al.
- What it means: This is the paper Europe PMC returns for registry id NCT02947685 with the most citations, so it is the natural first reading for anyone following the PATINA trial. Read the abstract above alongside the trial page and the registry entry; the record was linked automatically and its figures have not been checked by hand.
- Caveats: Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.

## Sources

- N Engl J Med 2026: https://doi.org/10.1056/nejmoa2511218
- PubMed: https://pubmed.ncbi.nlm.nih.gov/41604639/
- Europe PMC: https://europepmc.org/article/MED/41604639
- ClinicalTrials.gov NCT02947685: https://clinicaltrials.gov/study/NCT02947685

## Connected records

- trials: [PATINA](https://onco.cc/trials/patina/)
- journals: [New England Journal of Medicine](https://onco.cc/journals/nejm/)

---
JSON: https://onco.cc/api/v1/entities/paper-patina-n-engl-j-med-2026.json