Add-on pembrolizumab helps improve outcomes of relapsed, refractory Hodgkin lymphoma

Adding pembrolizumab to chemotherapy consisting of ifosfamide, carboplatin, and etoposide (ICE) in the treatment of patients with relapsed or refractory classic Hodgkin lymphoma appears to be well tolerated and associated with better outcomes in comparison with reports from studies on chemotherapy-only regimens, according to data from a phase II study.

A total of 42 patients were enrolled. They were given two cycles of pembrolizumab (200 mg intravenously on day 1) plus ICE chemotherapy every 21 days, followed by stem cell mobilization and collection, and then another cycle of pembrolizumab monotherapy followed by 18F-fluorodeoxyglucose–positron emission tomography with computed tomography (FDG-PET/CT) response assessment.

The primary endpoint was complete response rate detected by FDG-PET/CT (defined as a Deauville score of no more than 3). Patients with a complete response proceeded to receive an autologous stem cell transplant. Secondary endpoints included progression-free survival, overall survival, stem cell mobilization, and neutrophil and platelet engraftment. Adverse events were also monitored to evaluate safety.

Of the included patients, 37 (median age 34 years, 68 percent women, 70 percent White) had evaluable primary endpoint data. The complete response rate was 86.5 percent (95 percent confidence interval [CI], 71.2–95.5). The overall response rate was 97.3 percent (36 patients), with 10.8 percent of them achieving partial responses (four patients).

Results of biopsied new areas of FDG-PET positivity in two patients showed noncaseating granuloma and a reactive lymph node, respectively. The 2-year progression-free and overall survival estimates were 87.2 percent (95 percent CI, 77.3–98.3; 32 patients) and 95.1 percent (95 percent CI, 88.8–100), respectively.

The addition of pembrolizumab had no negative impact on stem cell mobilization or collection or engraftment, similar to prior experience in this patient population and setting.