Real-world duration of venetoclax treatment for chronic lymphocytic leukemia and small lymphocytic lymphoma

Introduction: Venetoclax (V) is an approved fixed-duration treatment (tx) for chronic lymphocytic leukemia and small lymphocytic lymphoma (CLL/SLL), as a 12-cycle regimen (∼12 mos) with obinutuzumab (O) in the first-line (1L) setting or as a 24-cycle regimen (∼24 mos) with rituximab (R) in the relapsed/refractory (R/R) setting. We analyzed real-world tx patterns of V+O in 1L and V+R in R/R settings in patients (pts) with CLL/SLL in the United States. Methods: A retrospective cohort analysis was conducted using the IQVIA PharMetrics® Plus database to identify pts ≥18 y treated with V+O (1L cohort; May 2019 to September 2021) or V+R (R/R cohort; June 2018 to September 2021). Start of tx regimen was defined as the index date. All pts were required to have ≥1 diagnosis code for CLL/SLL and continuous enrollment 12 mos prior to and ≥3 mos after index date. Duration of tx (DoT) was defined as time from index date to earliest of either tx discontinuation (i.e., ≥60-d gap in V prescription refills) or censoring (i.e., end of follow-up). Fixed-duration tx cycle was defined as 12- or 24-cycle dosing (days 336−364 for 1L setting and days 707−735 for R/R setting, based on the dosing schedule plus 28 days). Kaplan-Meier analysis was used to estimate the probability of remaining on tx for the 1L and R/R cohorts. Results: A total of 116 pts in 1L setting (mean age, 62.3 y) and 145 pts in R/R setting (mean age, 64.2 y) were identified; 48.3% of R/R pts had prior targeted therapy. Median (95% CI) DoT in V+O pts (n = 115) was 12.4 (11.5, 13.4) mos over a median follow-up of 11.4 mos; probability of remaining on tx at 12, 18, and 24 mos was 56.4%, 20.2%, and 5.1%. Median (95% CI) DoT in V+R pts (n = 133) was 24.5 (13.4, 25.2) mos over a median follow-up of 15.5 mos; probability of remaining on tx at 24, 30, and 36 mos was 53.8%, 19.0%, and 19.0%. Among V+O pts, 47.8% (55/115) had ≥12 mos follow-up, of whom 9.1% had fixed cycles and 38.2% discontinued early (median DoT: 4.6 mos). Among V+R pts, 29.3% (39/133) had ≥24 mos follow-up, of whom 5.1% had fixed cycles and 46.2% discontinued early (median DoT: 7.1 mos). The remaining pts in each cohort had DoT >12 or 24 cycles (Table). Conclusions: While median DoT was approximately 12 mos for V+O-treated pts (1L setting) and 24 mos for V+R-treated pts (R/R setting), a high number of pts did not maintain the fixed-dosing schedule. This study provides evidence that a V-based approach may not be suitable for all pts with CLL/SLL. Encore Abstract—previously submitted to regional or national meetings (up to <1’000 attendees), EHA 2023 The research was funded by: AstraZeneca Keyword: Chronic Lymphocytic Leukemia (CLL) Conflicts of interests pertinent to the abstract A. Teschemaker Employment or leadership position: AstraZeneca Stock ownership: AstraZeneca S. Hakre Employment or leadership position: AstraZeneca Stock ownership: AstraZeneca J. Tse Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study. N. F. Shaikh Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study. Y. Gu Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study. A. Near Research funding: AstraZeneca Pharmaceuticals. IQVIA received research funding from AstraZeneca to conduct this study.