Real-world outcome of patients with extensively pretreated multiple myeloma who were treated with selinexor and dexamethasone: a Korean multicenter retrospective analysis

The outcomes of patients with myeloma after exposed to penta-classes are extremely poor. Selinexor is the first approved exportin inhibitor for those patients, but intractable toxicities may limit its use. This retrospective study evaluated the real-world efficacy and safety of selinexor plus dexamethasone (XD) and involved 48 patients with multiple myeloma, who were treated from November 2020 to October 2022. Their median age was 64 years, and the median number of prior lines of therapy was 6. The overall response rate was 25%, and the median progression-free survival (PFS) was 2.1 months (95% confidence interval (CI), 1.7–2.5). Patients on a reduced initial dose, delayed treatment, and dose reduction had better PFS. After XD treatment failure, 17 patients received subsequent therapy and had a median PFS of 2.4 months. The median overall survival was 4.6 months (95% CI, 2.3–6.9). Among the patients, 12 (25%) and 17 (35%) experienced dose reduction and delayed treatment, respectively. Our data show that the real-world efficacy of XD treatment in heavily pretreated patients was modest and that improving treatment adherence through reducing initial doses or delaying treatments may improve patient outcomes.