Uveitis with teclistamab and elranatamab: infection or inflammation?

Background: In 2026, the US Food and Drug Administration (FDA) identified uveitis as a potential signal of serious risk for the B-cell maturation antigen (BCMA) x CD3 bispecific antibodies teclistamab and elranatamab. Uveitis in this setting may reflect opportunistic infection or immune-mediated inflammation, which require opposite management. Methods: We analyzed FDA Adverse Event Reporting System (FAERS) reports from July 2020 to June 2026 (8,690,601 reports after deduplication) using a case-non-case design, calculating reporting odds ratios (RORs) and the information component for primary-suspect reports. Comparators were belantamab mafodotin, talquetamab and CD3 bispecific antibodies used outside myeloma. Every primary-suspect uveitis report (n = 76) was classified as infectious, probable immune-mediated (hereafter immune-mediated) or indeterminate by a physician blinded to a rule-based algorithm. Results: Uveitis was reported in 18 of 2,995 teclistamab and 29 of 1,691 elranatamab reports (ROR 4.10 [95% CI 2.58-6.52] and 11.85 [8.21-17.12]). Of these 47 cases, 20 were infectious (18 cytomegalovirus chorioretinitis; median onset 92 days), and infection-specified uveitis was disproportionately reported for both agents and for CD3 bispecific antibodies used outside myeloma. Thirteen were immune-mediated, arose early (median onset 4 days) and were co-reported with cytokine release syndrome in six; immune-mediated uveitis showed a signal only for elranatamab (8 cases; ROR 3.59, 1.79-7.18), not for teclistamab or any comparator. Six of the eight elranatamab cases originated from Japan. Agreement between physician and algorithm was 98.7%. Conclusions: The FDA uveitis signal appears to comprise a late infectious uveitis shared by most T-cell-redirecting bispecific antibodies examined and an early immune-mediated uveitis that showed a signal only with elranatamab. These hypothesis-generating findings support prompt ophthalmological assessment of new visual symptoms and exclusion of cytomegalovirus retinitis before corticosteroids are started.