Real-World Outcomes of Melflufen Plus Dexamethasone in Heavily Pretreated Relapsed/Refractory Multiple Myeloma After...

The combination of melphalan fluflenamide (melflufen) and dexamethasone (melf-dex) is approved for patients with relapsed/refractory multiple myeloma (RRMM) after ≥3 prior lines of therapy; however, the results in patients outside clinical trials, particularly those receiving novel immunotherapies, remain limited.

We retrospectively collected data from patients with RRMM treated with melf-dex in the real-world setting at 8 Spanish institutions between June 2024 and May 2025.

Nineteen patients were included (median age, 64 years; median of 5 prior lines). Soft tissues plasmacytomas were present in 2 patients and high-risk cytogenetics in 7 (4 with ³2 high-risk abnormalities). Eighteen patients (95%) and 14 (74%) were triple and penta-class refractory, respectively. Fourteen patients (74%) had prior exposure to anti-BCMA/GPRC5D therapies, including 5 with dual exposure. Response rate was 28% (5/19) in the total cohort and 33% (4/13) in the immunotherapy-exposed subgroup; stable disease rates were 44% and 42%, respectively. Median progression-free survival was 4.8 months (95% CI: 2.5-not reached). At a median follow-up of 5.75 months, median overall survival was not reached. Three patients remained alive and responding beyond nine months. Grade ≥3 hematologic toxicities were common (thrombocytopenia 68%, neutropenia 68%, anemia 47%). One patient discontinued due to severe thrombocytopenia and bleeding, and one died of sepsis CONCLUSION: This is the first real-world report of melf-dex after novel immunotherapies, showing efficacy consistent with clinical trials. Melf-dex may be a valuable treatment option in very late relapse, although larger cohorts of patients and longer follow-up are needed.