A systematic review and meta-analysis estimated the frequency of second primary malignant neoplasms (SPMs) after T-cell-engaging bispecific antibody therapy in adult patients with B-cell non-Hodgkin lymphoma and multiple myeloma. Published on PubMed, the analysis pooled data from 20 studies (26 cohorts; 2,551 patients). Across studies reporting total SPMs, the pooled estimated proportion was 3.5% (95% CI, 1.8–6.9) at a median follow-up of 17.4 months. Estimates were broken out at about 3.8% for NHL and 3.4% for MM, while SPMs leading to treatment discontinuation pooled to 2.2% (95% CI, 1.5–3.1) and SPMs leading to death pooled to 1.4% (95% CI, 1.1–1.9). The authors note follow-up limitations, but concluded that SPMs are a measurable and clinically relevant complication of bispecific therapy, emphasizing the need for longer-term surveillance as these agents move earlier in treatment courses.