Pembrolizumab Approved for Relapsed/Refractory Adult and Pediatric Hodgkin Lymphoma

Merck has announced that its programmed death-1 inhibitor, pembrolizumab (Keytruda), has been approved for the treatment of adult and pediatric patients with refractory classical Hodgkin lymphoma (cHL) or those who have relapsed after at least 3 lines of therapy. This is an accelerated approval for the drug—proved clinical benefit from confirmatory trials will ensure continued approval.

The approval was based on results from the Keynote-087 trial, which recruited 210 patients with relapsed/refractory cHL, who:

• Had failed to achieve a response or progressed after autologous stem cell transplant (auto-SCT) and have relapsed after treatment with or failed to respond to brentuximab vedotin (BV) post auto-SCT
• Were unable to achieve a complete response or partial response to salvage chemotherapy and did not receive auto-SCT, but had relapsed after treatment with or failed to respond to BV
• Failed to achieve a response to or progressed after auto-SCT and had not received BV post auto-SCT.

The primary trial outcomes being measured included overall response rate (ORR), percentage of participants with at least 1 adverse event (AE), and percentage of participants discontinuing their study due to adverse events. Secondary outcomes were complete response rate (CRR), progression-free survival, duration of response, and overall survival.

At a median follow-up of 9.4 months, ORR was 69% (95% CI, 62—75) with 200 mg pembrolizumab administered every 3 weeks. CRR was 22% and the partial remission rate was 47%. Of the 145 patients who responded to treatment, the median duration of response was 11.1 months.

Only 5% of patients discontinued treatment due to AEs, but treatment was interrupted in another 26% due to AEs. Most frequent serious AEs, observed in 16% of patients, included pneumonia, pneumonitis, pyrexia, dyspnea, graft-versus-host disease (GVHD), and herpes zoster. Of 2 patients who died from causes other than disease progression, 1 died from GVHD and the other from septic shock.

The pediatric approval comes from data extrapolated from a pediatric melanoma trial.