Journal: The New England journal of medicine
Phase 3 PATINA trial – summary
Population
- • 518 patients with hormone receptor–positive, HER2-positive metastatic breast cancer
- • No progression after 4–8 cycles of first-line chemotherapy plus anti-HER2 therapy
- • Randomized 1:1 to:
- • Maintenance endocrine + HER2-targeted therapy + palbociclib
- • Maintenance endocrine + HER2-targeted therapy alone (standard)
Design
- • Open-label, randomized phase 3 trial
- • Primary endpoint: investigator-assessed progression-free survival (PFS)
- • Secondary endpoints: objective response, clinical benefit, safety, overall survival
Efficacy
- • Median follow-up: 53.5 months
- • Median PFS:
- • Palbociclib arm: 44.3 months
- • Standard arm: 29.1 months
- • Hazard ratio for progression or death: 0.75 (95% CI, 0.59–0.96; P=0.02)
- • Interpretation: Adding palbociclib to maintenance HER2-targeted plus endocrine therapy significantly prolongs PFS in this setting.
Safety
- • Grade 3 adverse events:
- • 79.7% with palbociclib vs 30.6% standard
- • Grade 4 adverse events:
- • 10.0% with palbociclib vs 3.6% standard
- • Toxicity was mainly neutropenia.
Conclusion
Maintenance palbociclib added to anti-HER2 and endocrine therapy after induction chemo–HER2 treatment significantly improves progression-free survival in HR+/HER2+ metastatic breast cancer but at the cost of substantially higher rates of (primarily neutropenic) grade 3–4 toxicity.