MM-404 Real-World Belantamab Mafodotin Use: A US Retrospective Longitudinal Pharmacy and Medical Open-Source Claims Database Assessment

Abstract

Belantamab mafodotin (belamaf) is an approved (August 2020), first-in-class, B-cell maturation antigen-targeting antibody-drug conjugate for patients with relapsed/refractory multiple myeloma (RRMM) who have received ≥4 prior therapies, including anti-CD38 monoclonal antibodies (mAB), proteasome inhibitors (PI), and immunomodulatory agents. The DREAMM-2 study, with single-agent belamaf, reported an overall response rate of 32% and an 11-month duration of response. Belamaf can cause ocular events manageable by dose holds/reductions. Examination of prior multiple myeloma (MM) treatments and belamaf treatment patterns for US patients initiating belamaf in real-world clinical practice. This descriptive, retrospective cohort study using IQVIA's longitudinal pharmacy and medical open-source US claims databases identified belamaf claims (August 2020-February 2022). Patients were followed for ≥6 months. The treatment period was the index date (first observed belamaf claim) through the last observed belamaf claim +21 days. The measures were demographic/clinical characteristics, prior MM treatments, recycled treatments, belamaf dose, and use patterns. Overall, 695 patients received belamaf (53% male, median age 70 years). Prior to belamaf, corticosteroid (99%), PI (89%), anti-CD38 mAB (83%), and immunomodulator (65%) treatments were common. A median of 4 therapeutic classes were used: 491 (71%) patients had ≥1 recycled treatment. Median follow-up was 307 (180-532) days; 210 (30%) patients had ≥6 months follow-up. The median belamaf treatment duration was 86 (22-455) days. The median number of administrations was 3. During follow-up, 49 patients (23%) had a 29-56-day treatment gap, and 63 (30%) had a treatment gap >56 days. Doses were administered a median of 22 days apart. The median belamaf dose was 170 mg at first dose/160 mg at fourth dose. Among patients with >1 evaluable dose (n=167), 119 (71%) had no dose reduction and 48 (29%) had ≥1. Eighty patients (38%) had concomitant therapies, most commonly dexamethasone (n=66). Belamaf is a treatment option for RRMM patients. Real-world evidence suggests that its use in clinical practice is generally consistent with the label indication, managed with dose reductions/holds, and that patients remain on therapy (consistent with the DREAMM-2 trial). Ongoing studies are examining alternative dosing schedules and combinations. GSK (214283). This abstract was previously presented at the 2022 International Myeloma Workshop.