Dr Schmid on the Use of Perioperative Pembrolizumab in TNBC

Peter Schmid, MD, PhD, clinical director, Breast Cancer Centre, honorary consultant medical oncologist, St. Bartholomew’s Hospital; chair, Cancer Medicine, lead, Centre of Experimental Cancer Medicine, leader, Academic Breast Cancer Programme, Barts Cancer Institute, Queen Mary University, discusses updated event-free survival findings from the phase 3 KEYNOTE-522 trial (NCT03036488) of neoadjuvant pembrolizumab (Keytruda) plus chemotherapy followed by adjuvant pembrolizumab in patients with early-stage triple-negative breast cancer. 

At the 2023 San Antonio Breast Cancer Symposium, Schmid presented 5-year follow-up data from KEYNOTE-522. Five years is an important time point in TNBC, because recurrences tend to occur early, Schmid notes. Approximately 65% to 70% of all recurrences in patients with TNBC happen within the first 3 years, and approximately 80% to 90% of recurrences occur within the first 5 years, Schmid explains.

In KEYNOTE-522, at a median follow-up of 63.1 months, the EFS rate was 81.3% in patients who received pembrolizumab vs 72.3% in those who received placebo (HR, 0.63; 95% CI, 0.49-0.81). This long-term follow-up analysis also showed relative and absolute EFS benefits with perioperative pembrolizumab plus chemotherapy vs placebo plus chemotherapy across several patient subgroups. In patients with stage II disease, the EFS rates were 85.6% and 77.5%, respectively (HR, 0.59; 95% CI, 0.43-0.82). In those with stage III disease, the EFS rates were 68.2% and 57.1%, respectively (HR, 0.71; 95% CI, 0.48-1.05). Furthermore, 76.8% of patients with node-positive disease who received pembrolizumab were event free vs 67.0% of those who received placebo (HR, 0.67; 95% CI, 0.49-0.93). Among patients with node-negative disease, the EFS rates were 86.3% and 77.8% in the pembrolizumab and placebo arms, respectively (HR, 0.56; 95% CI, 0.38-0.84).

Moreover, in patients with T2N0 tumors, the EFS rates with pembrolizumab vs placebo were 87.8% vs 77.9%, respectively (HR, 0.49; 95% CI, 0.31-0.78). This finding demonstrates that patients with small cancers have significantly improved outcomes when they receive pembrolizumab as part of their neoadjuvant treatment, Schmid concludes.

Disclosures: Dr Schmid reports consulting fees from Eli Lilly & Company and Gilead Science.