The U.S. Food and Drug Administration (FDA) approved venetoclax for the treatment of patients with chronic lymphocytic leukemia (CLL) who harbor the 17p deletion (del17p) and who have received at least one prior therapy. This is the first U.S. FDA-approved treatment that targets the B-cell lymphoma 2 protein. Previously, venetoclax had received orphan drug status for the treatment of CLL and was granted breakthrough therapy designation for the del17p CLL.
The drug’s approval was based on the results of a phase II, single-arm clinical trial of 106 patients with del17p CLL. Patients had been treated with a median of 2.5 prior treatments (range = 1-10). Patients received venetoclax 20 mg orally each day, with the dosage increasing to 400 mg over a five-week period.
The overall response rate was 80 percent (8% experienced a complete remission), with a median time to first response of 0.8 months. After approximately 12 months of follow-up, the median duration of response has yet to be reached.
The most common (≥20%), any-grade adverse events (AEs) were neutropenia, diarrhea, nausea, anemia, upper respiratory tract infection, thrombocytopenia, and fatigue. Serious AEs were reported in 44 percent of patients; the most common (≥2%) were pneumonia, febrile neutropenia, pyrexia, autoimmune hemolytic anemia, anemia, and tumor lysis syndrome.
Patients receiving venetoclax should not be given live attenuated vaccines.
Source: U.S. FDA press release, April 11, 2016.