NEW YORK – Merck on Thursday announced that the US Food and Drug Administration has accepted two new supplemental biologics license applications for the company's anti-PD-1 therapy pembrolizumab (Keytruda) for the treatment of triple-negative breast cancer.
With the first accepted application, Merck is seeking accelerated approval for pembrolizumab in combination with chemotherapy for patients with metastatic, locally recurrent, or unresectable triple-negative breast cancer whose tumors express a combined positive PD-L1 score of at least 10. With the second accepted application, Merck is seeking standard approval for pembrolizumab in combination with chemotherapy as a neoadjuvant treatment for patients with high-risk, early-stage triple-negative breast cancer followed by single-agent pembrolizumab as continued treatment post-surgery.
Merck has based the application for the first indication on the results of the Phase III Keynote-355 trial, and the application for the second indication on the results of the Phase III Keynote-522 trial. In the Keynote-355 trial, the pembrolizumab chemotherapy combination demonstrated a significant progression-free survival benefit for patients whose tumors expressed PD-L1 scores at or over 10. In the Keynote-522 trial — which Merck noted was the first randomized trial of an anti-PD-1 therapy in the neoadjuvant and adjuvant setting for triple-negative breast cancer — the drug regimen resulted in a statistically significant increase in pathologic complete response among women with early-stage triple-negative breast cancer, regardless of their tumors' levels of PD-L1 expression.
"There is a real need to advance new treatment options for triple-negative breast cancer, an aggressive form of the disease," Merck Research Laboratories' Senior VP, Head of Global Clinical Development, and Chief Medical Officer Roy Baynes said in a statement. “These acceptances mark the first US applications for Keytruda in breast cancer, and we look forward to working closely with the FDA to bring these new options to patients as quickly as possible.”
The target action dates that the FDA has set for the two applications are Nov. 28, 2020 and March 29, 2021, respectively.