Phase 2 BETTER trial tests pembrolizumab PD-1 blockade with taxane/platinum chemo de-escalation.

MD Anderson Cancer Center is running this Phase 2 neoadjuvant study in high-risk, early-stage triple-negative breast cancer (clinical stage T1cN1-2 or T2-4N0-2) to see whether blood-based ctDNA and breast MRI can identify patients who have already achieved a complete response after initial chemoimmunotherapy. Everyone receives pembrolizumab (Merck/MSD; PD-1–blocking monoclonal antibody) plus paclitaxel (microtubule/tubulin inhibitor) and carboplatin (platinum DNA–crosslinking agent) for 4 cycles, then is triaged into cohorts that either omit or receive additional anthracycline/cyclophosphamide (“AC”) before surgery based on response assessments. The core question is whether a subgroup with no residual MRI enhancement and undetectable ctDNA can safely skip anthracyclines—reducing cardiotoxicity and leukemia risk—without sacrificing pathologic complete response rates. Today’s care for stage II–III TNBC commonly uses pembrolizumab with multi-agent neoadjuvant chemotherapy (often including anthracycline + cyclophosphamide after taxane/platinum), followed by surgery and risk-adapted adjuvant therapy when residual disease remains.