Lin, Yi

ABSTRACT Ciltacabtagene autoleucel (cilta‐cel) has demonstrated excellent efficacy and long‐term disease control in patients with relapsed/refractory multiple myeloma (RRMM). However, a proportion of patients experience early treatment failures. We investigated clinical factors associated with early progression or death (within 12 months) in patients with RRMM receiving standard‐of‐care cilta‐cel across the three Mayo clinic centers. Patients with a follow‐up of at least 12 months or progression or death within 12 months from infusion were included. Of the patients with early treatment failure ( n = 52), 69% had progressive disease and 31% had a non‐relapse mortality (NRM) event. In patients without early treatment failure ( n = 164), 13% of events were NRM. Among pretreatment factors, prior BCMA‐directed therapy, presence of extramedullary disease and a CAR‐HEMATOTOX score of ≥ 2 were independent predictors of early progression or death. The utilization of cilta‐cel in earlier lines of treatment (1–3 vs. 4 or more) demonstrated comparable PFS (12‐month PFS 73% vs. 77%, p = 0.94). Measurable residual disease positivity in the bone marrow at 3 months (11/197 patients) identified a small but high‐risk group with an increased risk of early treatment failure (OR 5.68; p = 0.012). Patients with less than a complete response on a FDG PET/CT at 3 months also had an increased risk of early treatment failure (OR 11.8; p < 0.0001). Our findings may help identify patients at high‐risk for early adverse outcomes despite receiving highly effective therapy, and support consideration of novel therapeutic strategies within a clinical trial setting.

Abstract Extramedullary disease (EMD) is increasingly recognized in relapsed/refractory multiple myeloma (MM), with central nervous system involvement (CNS-MM) representing a rare but highly aggressive manifestation associated with dismal outcomes. Data on its incidence and optimal management, particularly in the era of cellular and bispecific therapies, remain limited. We conducted a retrospective analysis of patients with MM with pathology-confirmed EMD treated at our institution between January 2000 and December 2023. CNS-MM was defined by parenchymal or leptomeningeal involvement. Clinical features, cytogenetics, treatments, and outcomes were analyzed, with predictors of CNS involvement evaluated among patients with EMD. Among 304 patients with EMD, 20 (6.5%) had CNS-MM. CNS involvement occurred a median of 19.2 months after MM diagnosis, though 15% presented at diagnosis. CNS-MM was strongly associated with high-risk cytogenetics (odds ratio [OR], 3.7) and additional visceral EMD (OR, 4.6). Median overall survival (OS) from CNS-MM diagnosis was 4.2 months. Outcomes were significantly improved in patients receiving chimeric antigen receptor T-cell therapy or bispecific antibodies, with a median OS of 19.2 months vs 1.2 months in those who did not receive immune effector therapies. Intrathecal (IT) chemotherapy demonstrated limited and transient benefit. In conclusion, CNS-MM is an aggressive complication enriched in high-risk, multifocal EMD with extremely poor prognosis. Cellular and bispecific therapies show promising activity and may meaningfully improve survival, whereas IT therapy appears to have limited efficacy. Prospective studies are needed to define optimal treatment strategies for CNS-MM.