Key clinical point: Pembrolizumab showed manageable safety and promising clinical activity in patients with relapsed/refractory primary mediastinal large B-cell lymphoma (PMBCL).

Major finding: Among patients in KEYNOTE-013 and KEYNOTE-170, the objective response rates were 48% and 45%, respectively, including 33% and 13% of patients who achieved a complete response.

Study details: An analysis of a phase 1b study of 21 patients and a phase 2 study of 53 patients with relapsed/refractory PMBCL.

Disclosures: The study was supported by Merck Sharp & Dohme, the Harold and Virginia Lash Foundation, the Leukemia and Lymphoma Society, and the Center for Immuno-Oncology of the Dana-Farber Cancer Institute. The authors reported financial affiliations with Merck Sharp & Dohme and several other companies.