The PATINA trial shows that adding palbociclib to maintenance anti-HER2 and endocrine therapy significantly extends progression-free survival in HR-positive, HER2-positive advanced breast cancer, with a median PFS of 44.3 months versus 29.1 months.

The NEJM publication titles the work Palbociclib for Hormone-Receptor–Positive, HER2-Positive Advanced Breast Cancer, with a multinational team of authors led by researchers including Metzger and Mandrekar.

PATINA represents the first large randomized phase III trial to demonstrate a clinical benefit of CDK4/6 inhibition in HR+/HER2+ ABC, hinting at a potential maintenance-therapy approach for this subgroup.

Prior results were first presented at SABCS 2024, and the full trial protocol is listed on ClinicalTrials.gov (NCT02947685).

Key investigators highlighted the robustness of follow-up and a centralized database that supports mature PFS analysis.

No additional external information beyond the NEJM article link and social posts is included in the provided text.

Safety: palbociclib led to any-grade AEs in all patients, with higher Grade 3 AEs driven mainly by hematologic toxicity; dose reductions occurred in over half, and serious AEs were more frequent in the palbociclib group, though no treatment-related deaths occurred.

Safety findings align with the known palbociclib profile in this disease setting, with no new safety signals identified.

The reported hazard ratio for PFS is 0.75 with a p-value of 0.02, indicating statistical significance.

Overall survival data are immature at the final PFS analysis, with similar death counts between groups (approximately 60 vs 63) and a non-significant HR of 0.86.

The study was Pfizer-funded and supported by an academic collaboration led by Alliance Foundation Trials, with palbociclib not yet approved for HR+/HER2+ ABC.

Leading clinicians noted the potential paradigm shift in treatment for HR+/HER2+ metastatic breast cancer due to PATINA.