P1713: venetoclax in combination with obinutuzumab in first line chronic lymphocytic leukemia in argentina: a cost-effectiveness analysis

Background: The efficacy of venetoclax plus obinutuzumab (VenG) was examined in the CLL14 clinical trial, in unfit Chronic Lymphocytic Leukemia (CLL) patients who have not been previously treated. Aims: The aim of the study was to estimate the cost-effectiveness of VenG in the treatment of first-line unfit CLL patients in Argentina Methods: A three-state partitioned-survival model (with health states of progression-free survival (PFS), post-progression survival (PPS) and death), developed in accordance with NICE and ISPOR decision modelling guidelines, was adapted to Argentina setting and was used to estimate the accumulated costs and outcomes in terms of life years (LY) and quality-adjusted life years (QALY). A 30-year time horizon and the Social Security’s payer’s perspective were assumed. Cost-effectiveness was estimated by comparing a 12-month fixed duration of VenG versus (vs.) chlorambucil-obinutuzumab (ClbG) based on the CLL14 clinical trial. Other comparators included treat-to-progression therapies, such as ibrutinib (IBR), and a 6-month course of bendamustine + rituximab (BR). Using a network meta-analysis, the relative efficacy of VenG and ClbG vs. other selected comparators was estimated. Health state utilities and adverse event (AE) disutilities were derived from a systematic literature review and published health-technology assessment reports. To generate total quality-adjusted life years (QALYs), these health state utilities and AE disutilities were applied to the relative efficacy data. The cost of medication was based on country level drug prices. The healthcare resources used were validated by local experts through a Delphi panel methodology. Costs of resources used for routine medical attention and the management of adverse events were based on tariffs from social security system of Argentina. Costs were expressed in Argentine Pesos (AR$) (exchange rate 1 US dollars ($) = 100.75AR$, July 2021). A 5% annual discount rate was applied for costs and outcomes. Cost-effectiveness results are presented in terms of incremental cost per QALY. A new treatment that is both lower in total cost and more efficacious (in QALYs) vs. identified comparator treatments is described as being “dominant”. Uncertainty in the model was tested through one-way sensitivity analyses (OWSA) and probabilistic sensitivity analyses (PSA) Results: Over a 30-year time horizon, the total discounted costs were, for VenG, $117,250.19; ClbG, $167,675.26; BR, $206,951.64; and IBR, $432,243.36. The benefits in the cost-effectiveness model (CEM) were measured in terms of total discounted QALYs which were 5.634 for VenG, 5.350 for ClbG, 4.996 for BR and 5.161 for IBR. The incremental discounted QALYs of VenG was: 0.284 vs. ClbG, 0.639 vs. BR, and 0.473 vs. IBR. Thus, VenG with a 12-month fixed duration, has lower total costs and is more efficacious (“dominant”) over all comparators in the CEM. OWSA analyses show that the results are robust, and in the PSA VenG is dominant over all the comparators considered, ICER is ≤$ 6,011.20 (1 GDP per capita for Argentina, 2020), /QALY in 97% of the iterations CE Results - VenG ClbG BR IBR Costs $ 117,250.19 $ 167,675.26 $ 206,951.64 $ 432,243.36 LYs 12.80 12.80 11.88 11.88 QALYs 5.634 5.350 4.996 5.161 Incremental cost (vs VenG) $ -50,425.06 $ -89,701.44 $ -314,993.17 Incremental QALYs 0.284 0.639 0.473 Cost/QALYs gained Dominant Dominant Dominant Summary/Conclusion: This study shows that in Argentina, VenG would be dominant treatment option (better results and lower costs) compared with ClbG, BR and IBR in the treatment of first-line unfit CLL patients.