DREAMM-1 Patient perspectives from the first-in-human study of single-agent belantamab mafodotin for relapsed and refractory multiple myeloma (RRMM).

Abstract

e20531 Background: Patient-reported outcomes in RRMM remain poor, particularly for those refractory to immunomodulatory agents, proteasome inhibitors, and anti-CD38 antibodies, and there is an increased risk of cumulative toxicities in these patients. Single-agent belantamab mafodotin (GSK2857916), a first-in-class, B-cell maturation antigen–binding immunoconjugate, has demonstrated deep and durable responses with a manageable safety profile in heavily pretreated patients with RRMM (DREAMM-1, NCT02064387). Here, we present patient-reported clinical benefit/tolerability of belantamab mafodotin evaluated by trial-embedded end-of-treatment (EOT) and follow-up interviews. Methods: DREAMM-1 study design and results have been reported ( Blood Cancer J 2019). Patients in the Part 2 expansion phase were administered single-agent belantamab mafodotin 3.4 mg/kg IV once every 3 weeks for 16 cycles and invited to participate in interviews at EOT and 6-month follow-up. Patients discussed symptoms, treatment-related adverse events (AEs), treatment burden, and overall treatment satisfaction, rated 0–10 (0 = not severe to 10 = most severe/0 = not at all satisfied to 10 = extremely satisfied). Results: A total of 17/35 patients (9 female [53%]) were interviewed; 4/17 patients completed both interviews. Most patients (94%; 16/17) achieved a partial response or better. At EOT, patients reported an improvement from the worst point in symptoms of bone pain (mean change in score from 6.4 to 4.0) and fatigue (8.0 to 5.5). The most commonly reported treatment-related AE was blurred vision (76%; 13/17). Among those reporting this AE, 62% (8/13) reported resolution or steady improvement in vision after EOT; with a reduction in severity rating from 7.3 at worst to 5.3 at EOT for this event. Most patients (93%; 13/14) never considered stopping treatment owing to AEs, including ocular events. Overall treatment satisfaction was high (mean score 7.9; median 9.0). Conclusions: Despite small sample sizes, trial-embedded interviews provide valuable insight into patient experience with belantamab mafodotin. Patients treated with single-agent belantamab mafodotin reported high treatment satisfaction and improvements in symptoms. Visual symptoms were frequent but manageable, and improved or resolved after treatment. Funding: GlaxoSmithKline (117159). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT02064387.