The median duration of venetoclax treatment differed quite a bit from the recommended fixed-duration dosing schedules, according to a study presented at the 2023 National Comprehensive Cancer Network Annual Meeting in Orlando, Florida.
Venetoclax is a BH3-mimetic that blocks the B-cell lymphoma-2 (Bcl-2) protein. It treats first-line and relapsed/refractory chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). For first-line therapy, venetoclax is given with obinutuzumab in a 12-cycle (12-month) regimen. For relapsed/refractory CLL, venetoclax is combined with rituximab and given in a 24-cycle (24-month) regimen. However, the real-world dosing schedule, as determined by a review of the IQVIA PharMetrics® Plus database, differed in both situations.
“In the [first-line] setting, 26.1% of patients discontinued treatment early (on average, at 4.9 months), and 25.2% of patients exceeded the dosing schedule by an average of 2.7 months,” reported Anna Teschemaker of the Department of Global Medical Affairs, AstraZeneca Pharmaceuticals, Gaithersburg, Maryland, corresponding author of the AstraZeneca-funded study. “In the [relapsed/refractory] setting, 36.1% of patients discontinued treatment early (on average, 6.8 months) and 14.3% of patients exceeded the dosing schedule by an average of 5.6 months.”
These variations in treatment duration may cause some alarm, Teschemaker believes. “Venetoclax-based treatment approach for CLL/SLL patients could potentially lead to poor clinical outcomes for patients with early discontinuation, and for patients treated beyond the recommended regimen, it could lead to increase in costs, potential risk of adverse events, and with no evidence or label to support the extended DoT,” she reported.
Further studies are needed to determine whether treatment with venetoclax is appropriate for all patients with CLL/SLL, and the studies should address reasons for treatment discontinuation. In addition, patients older than 65 years were underrepresented in the review, so future studies should seek to determine the actual treatment duration in this demographic.
Teschemaker A, Hakre S, Tse J, et al. Real-world duration of venetoclax treatment for chronic lymphocytic leukemia and small lymphocytic leukemia (CLL/SLL). Presented at the 2023 National Comprehensive Cancer Network Annual Meeting, Orlando, Florida, March 31-April 2, 2003.