(125) Cost-effectiveness of epcoritamab vs glofitamab in relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) after at least 2 lines of therapy in the United States

Background: : Subcutaneous (SC) epcoritamab and intravenous (IV) glofitamab are US-approved CD3×CD20 bispecific antibody treatments for third-line plus relapsed/refractory diffuse large B-cell lymphoma (3L+ R/R DLBCL).

Objective: : This study evaluated the cost-effectiveness of epcoritamab vs glofitamab in R/R DLBCL after ≥2 therapy lines from a US healthcare perspective.

Methods: : A partitioned survival model with 3 health states (progression free, progressive disease, and death) based on overall survival (OS) and progression-free survival (PFS) was developed. Epcoritamab patient-level data were obtained from the DLBCL cohort of the EPCORE NHL-1 trial (NCT03625037, data cutoff April 2023, N=139). Publicly available aggregate data were used for the glofitamab trial cohort (NCT03075696, Dickinson et al. 2022, N=155). Parametric survival models were evaluated for statistical fit and clinical plausibility of epicoritamab extrapolated OS, PFS, and time to treatment discontinuation. Based on an unanchored matching-adjusted indirect comparison, a statistically significant OS benefit was demonstrated for epcoritamab vs glofitamab from 6 months onward (hazard ratio [HR] [95% CI]) ( < 6 months: 1.12 [0.72–1.74]; ≥6 months: 0.57 [0.34–0.94]). The PFS HR was 1.04 [0.77–1.40]. Health states utilities were based on EPCORE NHL-1 EQ-5D-3L data and published US value sets. Drug costs and other resource use data were based on package inserts, US standard sources (Redbook WAC, CMS physician fee schedules), and literature. Based on expert opinion, no additional drug costs were incurred for epcoritamab after 2 years in the base case. Outcomes and costs were discounted by 3% annually. Probabilistic, one-way sensitivity analyses and scenario analyses were used to assess model robustness.

Results: : Epcoritamab use resulted in a mean gain of 2.35 life years (LYs) and 1.33 quality-adjusted LYs (QALYs) vs glofitamab, with a cost difference of $125,797 over a lifetime horizon, leading to an incremental cost-effectiveness ratio (ICER) of $94,585 per QALY. Scenario analyses using a 3-year treatment duration and an unlimited epcoritamab treatment duration led to ICERs of $111,727 and $129,635, respectively. Epcoritamab was cost-effective vs glofitamab at a US willingness-to-pay threshold of $150,000 per QALY in the base case and scenario analyses. The average cost per LY was $53,140 less for epcoritamab vs glofitamab.

Conclusions: : SC epcoritamab provides meaningful LY and QALY gains vs IV glofitamab. This analysis demonstrates that epcoritamab is a cost-effective option for managing R/R DLBCL from a US healthcare perspective.

Sponsorship:: AbbVie; Genmab A/S