Phase I Study Indicates Pembrolizumab an Option in Heavily Pretreated Hodgkin Lymphoma

A small, early-stage study in patients with Hodgkin lymphoma who had failed multiple treatments or relapsed after stem cell transplant indicates that pembrolizumab could be a favorable treatment option in these patients.

Preliminary research studies have shown that patients with Hodgkin lymphoma may overexpress the programmed death ligand-1 (PD-1) protein on their cell surface, indicating that the tumors may be dependent on PD-1 for survival, and thus making it an ideal drug target. To test this hypothesis, the KEYNOTE-013 trial enrolled 31 patients with relapsed, refractory Hodgkin lymphoma who had progressed following treatment with brentuximab vedotin. Patients were treated with pembrolizumab every 2 weeks until week 12, and every 8 weeks after, until disease progression. Safety and complete remission (CR) rate were the primary trial endpoints.

Of the 31 patients, 55% had had more than 4 lines of therapy and 71% had relapsed following autologous stem cell transplant. The observed CR rate was 16% (90% CI, 7% to 31%). Nearly half (48%) the patients achieved a partial remission for an overall response rate of 65% (90% CI, 48% to 79%). A majority (70%) of the responses lasted for more than 6 months, with a median follow-up of 17 months.

The most commonly observed adverse events (AEs) were hypothyroidism (16%), diarrhea (16%), nausea (13%), and pneumonitis (10%). Grade 3 AEs were observed in 16% of patients, namely colitis, increased ALT and AST levels, nephrotic syndrome, joint swelling, back pain, and axillary pain. There were no grade 4 treatment-related AEs.

The authors feel that their results are a sufficient prerogative for further studies of pembrolizumab in patients with Hodgkin lymphoma.

The study is published in the November issue of the Journal of Clinical Oncology.