PD-1 Blockade After Avelumab in Relapsed/Refractory Classical Hodgkin Lymphoma.

ABSTRACT

BACKGROUND: Anti-PD-1 directed therapy is safe and effective in patients with relapsed/refractory (r/r) cHL and is currently being studied in the frontline setting. There are currently little data regarding the safety and efficacy of PD-1 blockade after prior PD-L1 blockade with agents such as avelumab. METHODS: This is a retrospective case series evaluating r/r cHL patients treated with avelumab who subsequently received at least 1 dose of PD-1 blockade. Primary objective is efficacy as measured by overall response rate. Secondary objectives include duration of response and time to progression on PD-1 blockade as well as safety as evaluated by incidence and severity of immune-related adverse events (irAE) with PD-1 blockade. RESULTS: There were 7 patients treated with PD-1 blockade after avelumab, of whom 4 were re-treated. The median follow-up was 46.8 months. At the time of PD-1 blockade initiation median age was 36.6 years, all patients had advanced stage, 1 patient had B symptoms, and 4 patients had extranodal disease. Patients received median 7 prior lines of therapy including avelumab. Median duration on anti-PD-1 treatment was 15.9 months. A response was observed in 86% of patients with median duration of response of 26.4 months and median time to progression of 22.2 months. Only 1 patient experienced an irAE (grade 2 pneumonitis). CONCLUSION: Our study suggests that PD-1 blockade after PD-L1 blockade in r/r cHL appears safe and may be effective with durable responses observed in a subset of patients.