Merck announced that the European Commission has approved KEYTRUDA, Merck's anti-PD-1 therapy, in combination with chemotherapy as neoadjuvant treatment, and then continued as monotherapy as adjuvant treatment after surgery for adults with locally advanced or early-stage triple-negative breast cancer (TNBC) at high risk of recurrence. The approval is based on results from the pivotal Phase 3 KEYNOTE-522 trial, in which KEYTRUDA in combination with chemotherapy before surgery and continued as a single agent after surgery prolonged event-free survival (EFS), reducing the risk of EFS events or death by 37% (HR=0.63 [95% CI, 0.48-0.82]; p=0.00031) compared to neoadjuvant chemotherapy alone in this patient population. Median follow-up time for all patients was 37.8 months (range, 2.7-48). KEYNOTE-522 was the first large, randomized Phase 3 study to report a statistically significant and clinically meaningful EFS result among patients with stage II and III TNBC. With this decision, this KEYTRUDA combination becomes the first immunotherapy option approved for patients in the European Union (EU) in this setting.
The safety of KEYTRUDA plus chemotherapy has been evaluated in 3,123 patients across tumor types. The incidence of Grade 3-5 adverse reactions in patients with TNBC was 80% for KEYTRUDA plus chemotherapy and 77% for chemotherapy. This approval allows marketing of this KEYTRUDA regimen in all 27 EU member states plus Iceland, Lichtenstein, Norway and Northern Ireland. This is the second indication for KEYTRUDA in breast cancer in Europe. In October 2021, KEYTRUDA plus chemotherapy was approved for the first-line treatment of certain patients with locally recurrent unresectable or metastatic TNBC.