Approval-standardized postmarketing safety reporting phenotypes of talquetamab versus BCMA-directed bispecific antibodies in multiple myeloma.

Bispecific antibodies directed against B-cell maturation antigen (BCMA) or G protein-coupled receptor class C group 5 member D have partly distinct toxicity profiles, but unequal time since approval complicates postmarketing comparisons. We used exact 24-month postapproval windows for teclistamab, elranatamab, and talquetamab in the FDA Adverse Event Reporting System (FAERS). Talquetamab was compared with pooled BCMA-directed reports across 12 prespecified toxicity domains using reporting-maturity×region-stratified Mantel-Haenszel (MH) odds ratios (ORs) with Holm correction. Among 3685 primary-suspect reports, talquetamab reporting was enriched for dysgeusia/taste disorder (MH OR 93.37, 95% CI 43.40-200.89), nail toxicity (72.21, 27.68-188.37), weight loss (10.53, 6.46-17.15), and skin toxicity (6.33, 4.83-8.29); infection was enriched among BCMA-directed reports (0.41, 0.33-0.50). All five differences preserved direction across prespecified sensitivity analyses and were recognized in registration-era evidence. The Japanese Adverse Drug Event Report database provided a secondary external-consistency assessment: pooled BCMA infection reporting was enriched (MH reporting odds ratio 3.30, 95% CI 2.65-4.12), predominantly reflecting elranatamab, whereas the teclistamab component was inconclusive. Only one postapproval talquetamab report was available in that database, precluding direct assessment of the four talquetamab-enriched phenotypes. Approval-standardized FAERS reporting identified registration-recognized phenotypes that may inform toxicity surveillance and supportive care. These estimates describe reporting composition, not incidence, comparative risk, or causal effects.