Five-Year Data Support Neoadjuvant Pembrolizumab/Chemo as SOC in TNBC

CancerNetwork^® spoke with Peter Schmid, MD, PhD, about how 5-year event-free survival (EFS) data from the phase 3 KEYNOTE-522 study (NCT03036488) presented at the 2023 San Antonio Breast Cancer Symposium (SABCS) support neoadjuvant pembrolizumab (Keytruda) plus chemotherapy followed by adjuvant pembrolizumab as a standard of care in early-stage triple-negative breast cancer (TNBC).

Schmid, a medical oncologist at Barts Cancer Institute of Queen Mary University of London, suggested that beginning immunotherapy following surgery in patients with stage II or III TNBC does not appear to be as effective compared with initiating treatment in the neoadjuvant setting. He described the importance of training the immune system with neoadjuvant immunotherapy to launch a T-cell response to the cancer cells.

In the KEYNOTE-522 trial, the 60-month EFS rate was 81.3% (95% CI, 78.4%-83.9%) in patients who received pembrolizumab before and after surgery compared with 72.3% (95% CI, 67.5%-76.5%) in those who received matched placebo. The median EFS was not reached in either treatment arm (HR, 0.63; 95% CI, 0.49-0.81).

Transcript:

I would hope that the 5-year data have demonstrated in a very clear way that the addition of pembrolizumab to neoadjuvant chemotherapy is the new standard of care for patients with stage II or III [triple-negative breast cancer]. If you also look at the wider context of [SABCS], there was an interesting trial in patients with the same [disease]: stage II/III triple-negative breast cancer. This time, chemotherapy and immunotherapy were given after surgery. What is interesting to see is, if you start immunotherapy after surgery, it seems to be ineffective. It seems to be [crucial for] the tumors around to train the immune system as to what the enemy is and launch that T-cell response to the cancer cells. We clearly have a standard of care in neoadjuvant therapy with chemotherapy and pembrolizumab for patients with stage II and stage III triple-negative breast cancer.

Reference

Schmid P, Cortés J, Dent R, et al. Neoadjuvant pembrolizumab or placebo plus chemotherapy followed by adjuvant pembrolizumab or placebo for early-stage triple-negative breast cancer: updated event-free survival results from the phase 3 KEYNOTE-522 study. Presented at the 2023 San Antonio Breast Cancer Symposium; December 5-9, 2023; San Antonio, TX; abstract LBO1-01.