Longer Overall Survival in Metastatic TNBC With Pembrolizumab

Pembrolizumab (Keytruda) added to first-line chemotherapy significantly improved overall survival (OS) for patients with metastatic triple-negative breast cancer (TNBC) whose tumors express a certain level of PD-L1, researchers reported at the virtual European Society for Medical Oncology (ESMO) virtual meeting.

In this exclusive MedPage Today video, Amy Tiersten, MD, of Mount Sinai Hospital in New York City, offers her takeaways from the KEYNOTE-355 trial.

Following is a transcript of her remarks:

Another really exciting clinical trial coming out of the ESMO meeting this year is a study looking at the addition of immunotherapy to standard chemotherapy for frontline treatment of triple-negative breast cancer.

Previously we had known that adding pembrolizumab to a variety of chemotherapy agents improved progression-free survival, but what these updated data show us is there’s an improvement in overall survival, which is something that’s really rarely seen in clinical trials for metastatic triple-negative breast cancer.

So at a median follow-up of 44 months, the overall survival was 23 months for the combination of pembrolizumab with chemotherapy versus 16 months for chemotherapy alone, which is I think, a meaningful clinical benefit. So immunotherapy has really been a game changer in oncology altogether, but breast cancer has sort of fallen behind in terms of the benefits seen in other tumor types.

I’m excited to be able to offer this to my patients in the frontline setting. Importantly, the benefit was only seen in patients with CPS, or combined positive score, greater than or equal to 10. And so for that subset of patients, this would be my standard frontline option.