1143 - The Economic Benefits of Time Off Treatment: Real-World HRU, Costs, and Subsequent Treatment with Fixed Duration Venetoclax among Patients with Chronic Lymphocytic Leukemia

Background: Fixed-duration (FTD) venetoclax-based regimens are approved for the treatment of chronic lymphocytic leukemia/small lymphocytic leukemia (CLL/SLL) in first-line (1L) as well as relapsed/refractory (RR) settings. Prior studies have described FTD as related to clinical trials or total cost of care; however, there are limited data characterizing the real-world benefits of FTD with venetoclax regimens. Preliminary data suggest that the FTD of venetoclax regimens may provide off-therapy economic benefits. This study quantifies the healthcare resource utilization (HRU) and costs during and post-completion of venetoclax plus obinutuzumab (VO) or venetoclax plus rituximab (VR) therapy and evaluates subsequent treatment patterns in patients with CLL/SLL in 1L and RR settings over an extended period.

Methods: Patients aged ≥18 years diagnosed with CLL/SLL between 1/1/2010 – 6/30/2021 who initiated VO in 1L or VR in RR settings were identified in the Optum® Clinformatics® database (Eden Prairie, MN). This analysis is an update of a previous cohort with an extended identification period allowing for the identification of 115 additional patients (total Nf223). Patients were continuously enrolled in their health plan for 1 year pre- and post-initiation with VO or VR. The follow-up period was stratified into two phases: 1) on-treatment phase, defined as time in months from venetoclax initiation to end of treatment; and 2) off-treatment phase, defined as time in months from 1 day after the end of venetoclax treatment to end of continuous enrollment/1 day before next line of therapy, or death. Per-patient, per-month (PPPM) all-cause HRU and costs were summarized using mean, standard deviation, or median, and interquartile range (IQR) in both on- and off-treatment phases. The proportion of patients who received subsequent lines of therapy after initiation with VO or VR are reported.

Results: In 1L, 115 VO-treated patients with a median follow up of 23.3 months were identified, with a median age at venetoclax initiation of 70 years, and 71.3% were male. The median (IQR) Charlson Comorbidity Index (CCI) score without malignancies was 1.0 (0–2). The median (IQR) duration of the on- and off-treatment phases were 12.4 (11.3–13.5) and 10.2 (5.6–15.1) months, respectively. Mean PPPM all-cause costs were $17,186 and $4,927 in the on- and off-treatment phases, respectively, representing a 71% reduction in costs after treatment completion (Table 1). The on-treatment costs were driven mainly by medication costs ($14,230 PPPM) relative to medical costs ($2,956 PPPM), while medical costs ($4,106 PPPM) accounted for most of the off-treatment costs. The mean PPPM all-cause outpatient visits were higher in the on- versus off-treatment phases (3.3 vs 1.8 visits). In patients treated with VO, only 9/115 (7.8%) patients moved on to a second line of therapy.

In the RR setting, 108 patients with a median follow up of 24.0 months, median age at VR initiation of 73 years, and 58.3% male were identified. The median (IQR) CCI score without malignancies was 1.0 (0–3). The median (IQR) duration of the on- and off-treatment phases were 16.1 (11.0–23.6) and 0.2 (0.0–9.9) months. Mean PPPM all-cause costs were $16,478 and $2,801 in the on- and off-treatment phases, respectively, representing an 83% reduction in costs after treatment completion. Medication costs ($12,766) accounted for most of the total cost in the on-treatment phase, while medical costs ($1,959) were the primary drivers of the off-treatment costs. Furthermore, the mean PPPM all-cause outpatient visits were higher in the on-treatment phase (3.2 vs 1.3). Less than one quarter (21/108 [19.4%]) of VR-treated patients received subsequent treatment during the follow-up period.

Conclusions: In this updated real-world cohort, patients treated with VO and VR had low rates of subsequent therapy during the available follow-up, consistent with previous findings, suggesting this is an effective therapy in these patients. There is also a reduction in healthcare cost when patients are off treatment. These findings illustrate the economic benefits of time off treatment as afforded by a FTD regimen. The full economic benefits of off-treatment in this analysis are limited by the duration of the follow-up, and future analyses with longer off-treatment period are warranted. Compared to indefinite therapy with Bruton's tyrosine kinase–inhibitor treatment, these results may carry implications not only for payers and access decisionmakers, but also considerations for shared decision making between physicians and patients.