Outcomes in Frail Patients Receiving BCMA-directed Bispecific Antibodies for Relapsed/Refractory Multiple Myeloma.

In addition to advanced age, patients with relapsed refractory multiple myeloma (RRMM) are often frail with pre-existing comorbidities and poor performance status and have been excluded from clinical trials evaluating bispecific antibodies (BsAb). To evaluate clinical characteristics and outcomes based on frailty, we conducted a single center retrospective study of patients with RRMM who received BCMA-directed BsAb. Frailty was defined using the simplified frailty index based on age, ECOG PS, and Charlson comorbidity index (CCI); non-frail = score 0-1, frail = score ≥2. Of 102 patients analyzed (age range 40 - 88), 40 (39%) were considered frail. The frail group had more patients with age ≥ 70 years (73% vs 29%, p <0.001), ECOG PS ≥ 2 (36% vs 0%, p <0.001), and worse median CCI (2 vs 1, p <0.001). Patients in the frail group experienced similar rates of all grade CRS (58% vs 60%, p= 0.99), ICANS (15% vs 8%, p= 0.44), and TRM (13% vs 21%, p= 0.27) compared to the non-frail group. Best overall response rate (ORR) was 80% (15% sCR/CR, 48% VGPR) in the frail group vs 73% (23% sCR/CR, 31% VGPR) in the non-frail group (p= 0.40). With a median follow-up of 8.6 months (range 3-14), there was no significant difference in median PFS (Not reached vs 11 months, p= 0.051) or OS (37 vs 25 months, p= 0.37) between the frail and non-frail groups, respectively. Hence, BsAb were deemed safe and effective for elderly and frail patients with RRMM.