- Pembrolizumab delivered high and durable response in patients with relapsed/refractory (R/R) primary mediastinal large B-cell lymphoma (PMBCL).
Why this matters
- R/R PMBCL is associated with poor prognosis, particularly in those ineligible for, or who relapse after, second-line autologous stem cell transplantation.
- Outcomes with pembrolizumab for 53 patients with R/R PMBCL from the phase 2 KEYNOTE-170 study and extended follow-up of 21 patients with R/R PMBCL from the phase 1b KEYNOTE-013 study.
- Funding: MSD; Harold and Virginia Lash Foundation; Leukemia and Lymphoma Society; Center for Immumo-Oncology of the Dana-Farber Cancer Institute.
- Objective response rate (ORR):
- KEYNOTE-013: 48% (95% CI, 26%-70%); 33% complete response (CR).
- KEYNOTE-170: 45% (95% CI, 32%-60%); 13% CR.
- Median duration of response (DOR) was not reached in KEYNOTE-013 (range, 1.9+ to 39.8+ months) or in KEYNOTE-170 (range, 1.1+ to 22.0+ months).
- 78% and 76% of patients had response durations of ≥12 months in KEYNOTE-013 and KEYNOTE-170, respectively.
- Estimated PFS at 12 months:
- KEYNOTE-013: 47%.
- KEYNOTE-170: 38%.
- Incidence of grade 3-4 adverse events:
- KEYNOTE-013: 24%.
- KEYNOTE-170: 23%.
- Responses were assessed using post hoc analysis for KEYNOTE-013.