Outcomes and prognostic indicators in daratumumab-refractory multiple myeloma: a multicenter real-world study of elotuzumab, pomalidomide, and dexamethasone in 247 patients

Background Daratumumab-refractory multiple myeloma (Dara-R MM) presents a significant treatment challenge. This study aimed to evaluate the efficacy and survival outcomes of elotuzumab, pomalidomide, and dexamethasone (EloPd) in a large, real-world cohort of patients with Dara-R MM, with particular focus on progression-free survival (PFS) and overall survival (OS). Materials and methods This retrospective analysis included 247 Dara-R MM patients treated with EloPd. All patients were also refractory to lenalidomide, with 51.4% to a proteasome inhibitor, thus classified as triple-class refractory (TCR). Survival risk-scoring systems for PFS (progression-free risk score-PRSDaraR) and OS (survival risk score-SRSDaraR) were developed to stratify patients based on their risk profiles. Results The overall response rate was 52.6%, with a median PFS and OS of 6.6 and 17.0 months, respectively. The International Staging System (ISS) stages II and III, low hemoglobin (Hb) levels, the last therapy being daratumumab, and symptomatic relapse were identified as significant independent predictors of shorter PFS in multivariable analysis. In addition to advanced ISS stages, low Hb levels (<10.6 g/dl), symptomatic relapse, and refractory disease exhibited an independent negative impact on OS. Importantly, no significant differences in both PFS and OS were observed between TCR and non-TCR patients. Based on these multivariable analyses, we developed PRSDaraR and SRSDaraR according to the magnitude of the hazard ratio. In PRSDaraR, 10.1% were low-risk, 41.3% intermediate, 43.3% high, and 5.3% very high-risk. The 12-month PFS probabilities were 86.3% (low), 67.6% (intermediate), 52.9% (high), and 31.8% (very high). For SRSDaraR, 6.1% were low-risk, 47.8% intermediate, 19.4% high, and 26.7% very high. The 12-month OS probabilities were 90.9% (low), 75.7% (intermediate), 55.9% (high), and 32.6% (very high). Conclusions This study supports EloPd as an effective treatment option in Dara-R MM patients, providing valuable disease control and acting as a potential bridge to newer therapies, such as CAR-T and bispecific antibodies.