Abstract
Overexpression of programmed death-1 (PD-1) ligands contributes to an immunosuppressive microenvironment. Nivolumab is a PD-1-blocking antibody that inhibits the PD-1 pathway and showed good efficacy in several types of malignancy. This phase II study examined the efficacy and safety of nivolumab in 17 Japanese patients with refractory/relapsed classical Hodgkin lymphoma previously treated with brentuximab vedotin. Sixteen patients were included in efficacy analyses and 17 in safety analyses. The primary endpoint was the centrally assessed objective response rate (ORR). The study was commenced in March 2015. We report data obtained at a cutoff of 16 March 2016, at which time 11 patients were still receiving nivolumab. The median (range) duration of treatment and follow-up were 7.0 (1.4-10.6) months and 9.8 (6.0-11.1) months, respectively. All 17 patients had previously received brentuximab vedotin. The ORR was 81.3% (95% confidence interval [CI]: 54.4-96.0%; 13/16 patients), with complete remission and partial remission in 4 and 9 patients, respectively. The overall survival (OS) and progression-free survival (PFS) rates at 6 months were 100 and 60.0% (95% CI: 31.8-79.7%), respectively; the median OS and PFS were not reached. The most common adverse events (AE) were pyrexia (41.2%), pruritus (35.3%), rash (35.3%) and hypothyroidism (29.4%). Four patients (23.5%) experienced grade 3 or 4 AE, but most AE were of grade 1 or 2. In conclusion, nivolumab is a potentially effective and tolerable treatment option for Japanese patients with relapsed/refractory classical Hodgkin lymphoma previously treated with brentuximab vedotin.