Classic HL vulnerable to PD-1 blockade therapy

All patients had failed therapy with brentuximab vedotin, 69% failed prior stem cell transplant, and 28% were transplant ineligible. Patients had to have an ECOG performance status of 0 or 1 and could not have autoimmune disease or interstitial lung disease.

Patients received 10 mg/kg of pembrolizumab intravenously every 2 weeks for up to 24 months or until progression.

Twenty-nine patients were evaluable for efficacy. The ORR was 66%, with a CR rate of 21% and a partial response rate of 45%. Twenty-one percent of patients had stable disease, and 14% had progressive disease. So the clinical benefit rate was 86%.

The median time to response was 12 weeks, and the median duration of response ranged from 1 to 185 days, but the median had not yet been reached.

Nine patients (31%) discontinued therapy, 1 (3%) due to an AE, 7 (24%) due to disease progression, and 1 (3%) after achieving a CR. Twenty patients (69%) were still on therapy at the time of the presentation, and 1 patient went on to transplant.

Sixteen patients (55%) experienced 1 or more treatment-related AE of any grade. Those occurring in 2 or more patients included hypothyroidism (10%), pneumonitis (10%), constipation (7%), diarrhea (7%), nausea (7%), hypercholesterolemia (7%), hypertriglyceridemia (7%), and hematuria (7%).

Treatment-related AEs of grade 3 or higher included axillary pain (3%), hypoxia (3%), joint swelling (3%), and pneumonitis (3%). Three patients experienced 4 grade 3 or higher AEs. There were no grade 4 treatment-related AEs or treatment-related deaths.

“In my opinion,” Dr Moskowitz concluded, “these results support continued development of pembrolizumab in Hodgkin lymphoma.”

“I think that these drugs are here to stay. Where we are going to put them in the armamentarium in Hodgkin lymphoma remains to be seen.”

This study was funded by Merck Sharp & Dohme Corp., the company developing pembrolizumab.

*Information in the abstract differs from that presented at the meeting.