Pembrolizumab Receives FDA Approval for Recurrent or Treatment-Resistant B-Cell Lymphoma

On 13 June 2018, the United States Food and Drug Administration FDA granted accelerated approval for refractory or recurrent disease after two or more treatment lines, primary mediastinal large B-cell lymphoma (PMBCL), in adult and pediatric patients, to pembrolizumab (Keytruda) , an immunotherapy drug.

• What is lymphoma, or lymph cancer? Symptoms and treatment

Approval was based on KEYNOTE-170, a multicenter, open-label, single-arm clinical trialenrolling 53 patients with relapsed or refractory primary mediastinal large B-cell lymphoma (PMBCL).

Patients were treated until unacceptable toxicity, documented disease progression, or, for continuing responders, up to 24 months, every 3 weeks intravenously with 200 mg pembrolizumab.

Overall response rate was %45: %11 had complete and %34 partial responses. At a median 9.7 months of follow-up, median response duration had not been reached because most continued responding. Median time to first objective response was 2.8 months; pembrolizumab is therefore not recommended for PMBCL requiring urgent cytoreductive treatment.

In KEYNOTE-170, common side effects in at least %10 of PMBCL patients were musculoskeletal pain, upper respiratory infection, fever, fatigue, cough, dyspnea, diarrhea, abdominal pain, nausea, arrhythmia and headache. Pembrolizumab was discontinued for adverse reactions in %8 and interrupted in %15. Among patients, % 25 had a side effect requiring systemic corticosteroids. Severe (grade 3 and 4) side effects occurred in %26.

• What are the side effects of immunotherapy drugs and how are they treated?

The recommended Keytruda dose for adults with PMBCL is every 3 weeks at 200 mg. The pediatric dose is every three weeks at 2 mg / kg (up to a maximum of 200 mg).

• What is the difference between leukemia and lymphoma?