Dr Gatti-Mays on the Use of Neoadjuvant Chemoimmunotherapy in Early-Stage TNBC

Margaret E. Gatti-Mays, MD, MPH, FACP, section chief, Breast Medical Oncology, associate professor, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center (OSUCC), OSUCC–James, discusses the current use of neoadjuvant chemoimmunotherapy in early-stage triple–negative breast cancer (TNBC).

In the early breast cancer setting, patients with tumors that are 2 cm or larger, or those with tumors involving the lymph nodes at baseline, are considered candidates for neoadjuvant chemoimmunotherapy, Gatti-Mays begins. The current standard of care, as established by the phase 3 KEYNOTE-522 trial (NCT03036488), supports the use of pembrolizumab (Keytruda) in combination with chemotherapy followed by adjuvant pembrolizumab for patients with early-stage disease, Gatti-Mays details. This randomized, multicenter, double-blind, placebo-controlled trial enrolled 1174 patients with newly diagnosed, previously untreated high-risk early-stage TNBC. Patients were enrolled onto the study regardless of tumor PD-L1 expression.

Initial results from KEYNOTE-522, which were previously reported, primarily focused on the achievement of pathologic complete response (pCR) in TNBC, she continues, adding that pCR is often used as a surrogate endpoint for event-free survival (EFS) in TNBC. The trial demonstrated a pCR rate of 63% (95% CI, 59.5%, 66.4%) among patients receiving pembrolizumab plus chemotherapy, compared with 56% (95% CI, 50.6%, 60.6%) among those receiving chemotherapy alone, Gatti-Mays reports. Additionally, the study reported that fewer patients experienced an event related to EFS in the pembrolizumab plus chemotherapy group compared with the chemotherapy-alone group, at 16% vs 24%, respectively (HR, 0.63; 95% CI, 0.48%-0.82%; P = .00031).

Based on interim findings from KEYNOTE-522, the FDA approved this neoadjuvant combination in this specified patient population in July 2021. This approval signifies the clinical benefit and improved outcomes associated with adding pembrolizumab to standard chemotherapy in the neoadjuvant setting for patients with early-stage disease, Gatti-Mays concludes.