KEYNOTE-522 Regimen for Early Triple-Negative Breast Cancer
Based on the KEYNOTE-522 trial, patients receive 4 cycles of pembrolizumab with carboplatin and paclitaxel, followed by 4 cycles of pembrolizumab with doxorubicin/epirubicin and cyclophosphamide in the neoadjuvant setting, then 9 cycles of adjuvant pembrolizumab after surgery. 1, 2, 3
Detailed Treatment Schedule
Neoadjuvant Phase (Before Surgery)
First 4 cycles:
- Pembrolizumab 200 mg IV every 3 weeks
- Carboplatin (dose per protocol)
- Paclitaxel (dose per protocol)
Next 4 cycles:
- Pembrolizumab 200 mg IV every 3 weeks
- Cyclophosphamide (dose per protocol)
- Doxorubicin OR epirubicin (dose per protocol)
Surgical Intervention
Definitive surgery performed after completion of 8 neoadjuvant cycles
Adjuvant Phase (After Surgery)
9 additional cycles:
- Pembrolizumab 200 mg IV every 3 weeks
- Continue until completion of 9 cycles, disease recurrence, or unacceptable toxicity
Total Treatment Duration
The complete KEYNOTE-522 regimen spans approximately 24 months total 3:
- 8 cycles neoadjuvant (approximately 24 weeks)
- Surgery
- 9 cycles adjuvant (approximately 27 weeks)
This represents the current standard of care for stage II-III triple-negative breast cancer, demonstrating significant improvements in pathological complete response (64.8% vs 51.2%), event-free survival, and overall survival (86.6% at 60 months vs 81.7%) 1, 4, 3.
Key Clinical Considerations
The NCCN designates this as a Category 1 recommendation for stage II-III TNBC 1. The regimen showed consistent benefit regardless of PD-L1 status and across all residual cancer burden categories, with particular benefit in RCB-2 patients 5.