Checkpoint Inhibitors in Relapsed/Refractory Classical Hodgkin Lymphoma

Even though classical Hodgkin lymphoma is highly curable, the outcome of patients with a refractory or relapsed disease has been disappointing. Multiple lines of therapy are available for patients after their first failure, and most respond to subsequent therapies. However, there is a sizable proportion that remains relapsing/recurrent even after several lines of therapy. The overall prognosis of patients with relapsing and recurrent classical Hodgkin lymphoma (rrcHL) has been very disappointing until recently. Immune checkpoint inhibitors such as the anti-programmed death 1 (PD-1) receptor antibodies have recently been approved to treat relapsed and refractory cHL and have significantly improved the outcome of patients with rrcHL. The approved immune checkpoint inhibitors for relapsed and refractory cHL are nivolumab and pembrolizumab. In the Checkmate 205 study nivolumab demonstrated an objective response rate of 69% with an acceptable safety profile. Similarly, pembrolizumab demonstrated an overall response rate (ORR) of 69% with a complete remission rate (CRR) of 22.4% in the KEYNOTE-087 study in heavily pretreated patients with rrcHL.