FDA grants priority review to Keytruda for primary mediastinal large B-cell lymphoma

The FDA granted priority review to pembrolizumab for treatment of patients with relapsed or refractory primary mediastinal large B-cell lymphoma, according to the agent’s manufacturer.

The FDA based the priority review designation on results of the phase 2 KEYNOTE-170 trial, which included a cohort of 29 patients with primary mediastinal large B-cell lymphoma, a type of non-Hodgkin lymphoma.

All patients failed two or more lines of therapy, and they either relapsed after or were refractory to autologous stem cell transplant or were ineligible for transplant.

Results showed pembrolizumab (Keytruda, Merck) — an anti-PD-1 therapy — induced an overall response rate of 41%. Researchers reported seven (24%) complete responses and five (17%) partial responses.

Median time to response was 2.8 months (range, 2.4-5.5), and median duration of response was not reached (range, 1.1+ to 13.6+).

“There is a significant unmet need for patients with relapsed or refractory primary mediastinal large B-cell lymphoma,” Pier Luigi Zinzani, MD, PhD, associate professor of hematology at Institute of Hematology Seràgnoli at University of Bologna, said in a Merck-issued press release. “These encouraging results represent another step in understanding the potential of Keytruda to help these patients who have already tried and progressed on prior therapies.”

Thirty patients (57%) in the KEYNOTE-170 trial experienced treatment-related adverse events, and 11 (21%) experienced grade 3 or grade 4 events. The most common treatment-related adverse events were neutropenia (n = 11), hypothyroidism (n = 4), asthenia (n = 3) and pyrexia (n = 3).

No treatment-related deaths occurred.

The FDA is expected to make a decision on this supplemental biologics license application by April 3.

Pembrolizumab already is approved for a variety of indications, including as treatment for certain patients with melanoma, lung cancer, head and neck squamous cell carcinoma, classical Hodgkin lymphoma, gastric cancer, urothelial carcinoma and microsatellite instability-high cancers.