Research in context
Evidence before this study
We searched PubMed with the keywords “classical Hodgkin lymphoma” and “programmed death 1” filtered by “article type: clinical trial” and “publication dates: 01/01/2015 to 05/01/2020” with no language restrictions, which yielded six results. All publications identified were phase 1 or 2 clinical trials in the non-curative setting. One publication was from the phase 1 KEYNOTE-013 study, which evaluated the PD-1 inhibitor pembrolizumab in patients with classical Hodgkin lymphoma after progression on brentuximab vedotin. Two publications were for the phase 2 KEYNOTE-087 study, which evaluated pembrolizumab in relapsed or refractory classical Hodgkin lymphoma, two publications were for the phase 2 CheckMate 205 study of the PD-1 inhibitor nivolumab in relapsed or refractory classical Hodgkin lymphoma after failure of autologous haematopoietic stem-cell transplantation (HSCT), and one study included multiple phase 1/2 cohorts of nivolumab monotherapy or combination therapy in several relapsed or refractory haematological malignancies. Results from these studies showed clinical benefit and favourable safety with both PD-1 inhibitors. In both the KEYNOTE-087 and CheckMate 205 studies, patients with previous brentuximab vedotin treatment had response rates similar to those of patients without previous brentuximab vedotin, indicating that anti-PD-1 antibodies are efficacious regardless of previous brentuximab vedotin treatment. Pivotal data with brentuximab vedotin in patients with classical Hodgkin lymphoma provided a benchmark for progression-free survival and acceptable toxicity that established brentuximab vedotin in this setting.
Added value of this study
We evaluated pembrolizumab monotherapy versus brentuximab vedotin in patients with relapsed or refractory classical Hodgkin lymphoma who had relapsed after autologous HSCT or who were ineligible for autologous HSCT. In this study, progression-free survival was significantly improved with pembrolizumab compared with brentuximab vedotin, and patients receiving pembrolizumab showed a consistent benefit in progression-free survival compared with those receiving brentuximab vedotin across multiple subgroups, including those with primary refractory disease and those ineligible for autologous HSCT.
Implications of all the available evidence
Results from the KEYNOTE-204 study add further evidence for the utility of PD-1 blockade in the treatment of relapsed or refractory classical Hodgkin lymphoma and establish a new potential standard of care for patients with relapsed or refractory classical Hodgkin lymphoma who relapse after autologous HSCT or who are ineligible for autologous HSCT.