ASCO 2022 | Exploratory analysis of KEYNOTE-522: EFS after neoadjuvant pembro + chemo Vs chemo for early TNBC

Lajos Pusztai, MD, DPhil, Yale School of Medicine, New Haven, CT, provides an overview on the exploratory analysis of the Phase III KEYNOTE-522 (NCT03036488) trial on event-free survival (EFS) by residual cancer burden after neoadjuvant pembrolizumab plus chemotherapy versus placebo plus chemotherapy for early triple-negative breast cancer (TNBC). The analysis included distributing residual cancer burden (RCB) into four categories of residual disease corresponding to pathologic complete response (pCR), from RCB0 corresponding to no residual disease up to RCD3 relating to extensive residual disease. The final results demonstrate a continued improvement in pCR rate at 8%, although this was less than observed in the primary analysis where a 13% improvement was shown. A significant improvement in event-free survival (EFS) was observed in the RCD2 category, corresponding to patients with moderate levels of residual disease deriving benefit from pembrolizumab in the neoadjuvant followed by the adjuvant setting, indicating the benefit of pembrolizumab extends beyond increasing pCR rate. This interview took place at the American Society of Clinical Oncology (ASCO) 2022 Annual Meeting in Chicago, IL.