(385) Real-world treatment history and economic outcomes of CD38 antibody-based regimens in relapsed/refractory multiple myeloma in the United States

Background: : Multiple myeloma (MM) accounts for approximately 2% of all cancer diagnoses and deaths in the US, with 36,110 new cases and 12,030 deaths expected in 2025. Despite therapeutic advances, most patients eventually relapse and develop drug resistance. Anti-CD38 monoclonal antibodies, including isatuximab (Isa) and daratumumab (Dara) are indicated in relapsed/refractory MM (RRMM), but limited evidence exists on treatment patterns and economic outcomes.

Objective: : To describe treatment history and costs associated with anti-CD38 agents in combination with pomalidomide and dexamethasone (Pd) or carfilzomib and dexamethasone (Kd), in RRMM in a real-world setting.

Methods: : A retrospective cohort study was conducted using the Komodo Health’s Research Grade claims data (Jan 2016–Feb 2024) on adults with RRMM who initiated Isa- or Dara-based regimens after Mar 2020 (post-FDA approval of Isa). The index date was the CD38 regimen initiation. Treatment history (number of prior lines of treatment, CD38 exposure, stem cell transplant [SCT] status), and 12-month post-index direct healthcare costs were reported descriptively.

Results: : A total of 154 Isa- (53% Isa-PD, 47% Isa-Kd) and 1,262 Dara-treated (67% Dara-Pd, 33% Dara-Kd) RRMM patients were included, with median age of 67 and 66 years, 43% and 47% female, 43% and 44% non-White, and 57% and 53% covered by Medicare, respectively. Isa-treated patients had higher baseline comorbidity burden compared with Dara-treated patients: 23% vs 16% with anemia, 25% vs 23% with renal impairment, and 12% vs 9% with skeletal-related events (similar hypercalcemia at 8%). Prior use of SCT was lower (21% vs 25%) and prior use of anti-CD38 agents was higher (58% vs 4%) in Isa- than Dara-treated patients. Isa-based regimens were received in later lines than Dara-based, with 32% and 17% observed with ≥3 prior lines of therapy, respectively. Mean total 12-month healthcare costs (2023 USD) were $365,456 in Isa- and $439,673 in Dara-treated patients. During this period, mean per-patient-per-month costs were $36,983 in Isa- and $39,130 in Dara-treated patients, with cost difference primarily driven by lower MM treatment costs in Isa-treated patients ($24,835 vs $29,880).

Conclusions: : Despite a higher disease burden at treatment initiation, Isa-treated patients incurred lower economic burden than those receiving Dara-based regimens, which was mainly driven by the cost of medication. Given similar efficacy and safety profile, Isa may be a compelling treatment option for RRMM from the healthcare payer’s perspective.

Sponsorship:: Sanofi