A systematic review and meta-analysis quantified second primary malignant neoplasms (SPMs) after T-cell-engaging bispecific antibody therapy in adults with B-cell non-Hodgkin lymphoma and multiple myeloma. The analysis, published in a PubMed-indexed study, pooled data from 20 studies comprising 2,551 patients with total follow-up limitations typical of emerging long-term safety evidence. The meta-analysis estimated a pooled proportion of 3.5% for reported total SPMs across cohorts with a median follow-up of 17.4 months. Disease-specific estimates were 3.8% for NHL and 3.4% for MM, while pooled estimates were 2.2% for SPMs leading to treatment discontinuation and 1.4% for SPMs leading to death. The authors reported that exploratory meta-regression did not identify study-level covariates linked to total SPM estimates, while concluding the SPM signal is measurable and clinically relevant even with relatively short follow-up. The finding is positioned as a longer-term safety metric for clinicians monitoring patients as bispecifics move earlier and broaden use.