Merck's KEYNOTE-522 Shows Promising Survival Data in TNBC

Leading drugmaker Merck has revealed the first-ever presentation of overall survival (OS) data from the Phase 3 KEYNOTE-522 trial, which assessed the anti-PD-1 therapy KEYTRUDA® (pembrolizumab) in combination with chemotherapy as a pre-operative treatment and as a stand-alone treatment after surgery for patients with high-risk early-stage triple-negative breast cancer (TNBC). When compared to the chemotherapy-placebo regimen, the KEYTRUDA regimen significantly improved overall survival (OS) and reduced the chance of mortality in patients with high-risk early-stage TNBC by 34%. those on the KEYTRUDA regimen had a five-year OS rate of 86.6%, whereas those on the chemotherapy-placebo treatment had an OS rate of 81.7%. Neither group was able to attain the median OS. With no new safety signals noted, KEYTRUDA's safety profile matched that of earlier research that were published.

 The results are being concurrently published in the New England Journal of Medicine and are being presented for the first time at the European Society for Medical Oncology (ESMO) Congress 2024 at a Presidential Symposium session. When compared to placebo plus chemotherapy followed by placebo after surgery in patients with high-risk early-stage TNBC, KEYTRUDA is the first and only immunotherapy-based regimen to demonstrate a statistically significant and clinically meaningful improvement in OS as neoadjuvant treatment with chemotherapy and then continued as a single agent as adjuvant treatment.

One of the four Phase 3 studies of a KEYTRUDA-based regimen in an earlier stage of cancer to show an OS benefit is KEYNOTE-522. The other three studies are KEYNOTE-A18 in newly diagnosed high-risk locally advanced cervical cancer, KEYNOTE-671 in non-small cell lung cancer that is resectable at stage II, IIIA, or IIIB, and KEYNOTE-564 in renal cell carcinoma for patients at intermediate-high or high risk of recurrence after nephrectomy or after nephrectomy and resection of metastatic lesions (in comparison to placebo).