Venetoclax receives regular approval for CLL, small lymphocytic lymphoma
The FDA has granted regular approval to venetoclax for patients with chronic lymphocytic leukemia or small lymphocytic lymphoma, with or without 17p deletion, who have received at least one prior therapy.
The approval of venetoclax (Venclexta; AbbVie, Genentech) was based on the results of the randomized, multicenter, open-label MURANO trial which observed the effect of venetoclax with rituximab (VEN+R) vs. bendamustine with rituximab (B+R) in 389 patients with CLL who had received at least one prior line of therapy.
According to a press release from the FDA, patients in the VEN+R arm completed a 5-week ramp-up venetoclax schedule and then received venetoclax 400 mg once daily for 24 months measured from the rituximab (Rituxan; Genentech, Biogen) start date. Rituximab was initiated after venetoclax ramp-up and given for six cycles (375 mg/m2 intravenously on cycle 1 day 1 and 500 mg/m2 intravenously on day 1 of cycles 2 to 6, with a 28-day cycle length). Patients in the comparator arm received six cycles of B+R (bendamustine 70 mg/m2 on days 1 and 2 of each 28-day cycle and rituximab at the same dose and schedule in the VEN+R arm).
Efficacy was defined as PFS as assessed by an Independent Review Committee. At a median follow-up of 23 months, the median PFS was not reached in the VEN+R arm and was 18.1 months (95% CI, 15.8-22.3) in the B+R arm (HR = 0.19; 95% CI, 0.13, 0.28). The overall response rate was 92% in the VEN+R arm compared with 72% for those treated with B+R.
The most common adverse reactions among patients treated with VEN+R were neutropenia, diarrhea, upper respiratory tract infection, fatigue, cough, and nausea. A total of 64% of patients developed Grade 3 or 4 neutropenia and grade 4 neutropenia developed in 31%. Additionally, serious adverse reactions occurred in 46% of patients and serious infections developed in 21% of patients, most commonly pneumonia (9%).
According to the release from the FDA, tumor lysis syndrome is an important identified risk with venetoclax treatment, due to the rapid reduction in tumor volume and urges patients to see the prescribing information for TLS risk stratification, prophylaxis and monitoring.