Low-dose pembrolizumab and nivolumab were efficacious and safe in relapsed and refractory classical Hodgkin lymphoma: Experience in a resource-constrained setting

The efficacy and safety of low-dose anti-PD1 antibodies in relapsed/refractory classical Hodgkin lymphoma (cHL) require confirmation. Pembrolizumab (100 mg every 3 weeks, Q3W) or nivolumab (40 mg Q2W) were administered to patients with relapsed/refractory cHL. In the pembrolizumab cohort (N = 11), who had failed a median of three (1–6) therapies (brentuximab vedotin [BV]: 91%; autologous hematopoietic stem cell transplantation [auto-HSCT]: 18%), the overall response rate (ORR) by positron emission tomography–computed tomography was 100% (metabolic complete response [mCR]: 73%; partial response [PR]: 27%). Median cumulative dose for achieving best response was 400 (300–800) mg. Median progression-free survival (PFS) was 35 months. Median overall survival (OS) was not reached. Adverse events (AEs) of grade 1–2 were observed in three patients. In the nivolumab cohort (N = 6), who had failed a median of three (2–6) therapies (BV: 50%; auto-HSCT: 17%; allogeneic HSCT: 34%), the ORR was 100% (mCR: 67%; PR: 17%; indeterminate response: 17%). Median cumulative dose for achieving best response was 160 (160–360) mg. Median PFS was 33 months. Median OS was not reached. AEs of grade 1–2 were observed in four patients, two of whom had pre-existing autoimmune conditions. Five patients with Epstein–Barr virus (EBV) positive Reed–Sternberg cells underwent monitoring of plasma EBV DNA, which became negative in four mCR patients but remained positive in one PR patient who died ultimately from refractory lymphoma. Low-dose pembrolizumab and nivolumab were highly efficacious and safe in relapsed/refractory cHL. These observations have significant financial implications in resource-constrained settings.