Abstract B104: Comparative Efficacy of Pomalidomide vs. Teclistamab in Preventing AL Amyloidosis Progression in Refractory Multiple Myeloma

Abstract Background: AL amyloidosis progression is a critical complication in patients with refractory multiple myeloma (MM), leading to poor outcomes. Pomalidomide, an immunomodulatory drug, and Teclistamab, a bispecific antibody targeting BCMA, are both used in the management of refractory MM. This study compares the efficacy of Pomalidomide versus Teclistamab in preventing the progression of AL amyloidosis in this patient population. Methods: We conducted a retrospective cohort study utilizing de-identified patient data from the TriNetX platform, which comprises electronic health records (EHRs) from 152 million patients across 128 healthcare systems in 18 countries. The study focused on 1,560 patients with relapsed/refractory multiple myeloma, comparing AL amyloidosis progression in those treated with Pomalidomide (n=779) versus Teclistamab (n=781). The primary outcome assessed was the risk of AL amyloidosis progression during treatment with Pomalidomide vs. Teclistamab. Propensity score matching was employed to balance baseline characteristics, including age, sex, ethnicity, and comorbidities, between the two cohorts. Results: In the Pomalidomide-treated group, 17 patients experienced AL amyloidosis progression, yielding a risk of 2.18%. In the Teclistamab-treated group, 12 patients had disease progression, with a risk of 1.38%. While Teclistamab demonstrated a lower risk compared to Pomalidomide, the difference was not statistically significant (p=0.1720). The calculated risk ratio (RR) was 1.704 (95% CI: 0.785, 3.699). Conclusion: Although Teclistamab showed a numerically lower risk of AL amyloidosis progression compared to Pomalidomide, the difference did not reach statistical significance. Further prospective studies are warranted to determine whether Teclistamab offers a superior protective effect against AL amyloidosis in refractory multiple myeloma. These findings highlight the need for additional research to optimize therapeutic strategies for this high-risk population. Citation Format: Allen Seylani, Yohannes Haile, Assal Sadighian. Comparative Efficacy of Pomalidomide vs. Teclistamab in Preventing AL Amyloidosis Progression in Refractory Multiple Myeloma [abstract]. In: Proceedings of the AACR IO Conference: Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2025 Feb 23-26; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2025;13(2 Suppl):Abstract nr B104.