410P Subsequent treatment (tx) patterns and impact on patient (pt) outcomes in the phase III ADRIATIC study of consolidation durvalumab (D) after concurrent chemoradiotherapy (cCRT) in limited-stage SCLC (LS-SCLC)

409O N (%) Total (N45) Any grade Grade 3 Obrixtamig or ezabenlimab-related AEs* 44 (98) 23 (51) Cytokine release syndrome (CRS) 35 (78) 0 (0) Dysgeusia 20 (44) 0 (0) Fatigue 17 (38) 2 (4) Lymphocyte count decreased 16 (36) 15 (33) Decreased appetite 16 (36) 1 (2) Nausea 10 (22) 0 (0) Rash 9 (20) 0 (0) Obrixtamig-related potential neurological toxicity including ICANS 6 (13) 3 (7) ICANS 2 (4) 2 (4) Immune-mediated encephalopathy 1 (2) 1 (2) Confusional state 1 (2) 0 (0) Disturbance in attention 1 (2) 0 (0) Lethargy 1 (2) 0 (0) Leukoencephalopathy 1 (2) 0 (0) *In 20% of pts. Grouped term.Conclusions: Obrixtamig + ezabenlimab showed manageable safety and tolerability in pts with pretreated DLL3+ NECs.Encouraging efficacy was observed particularly at higher doses of obrixtamig and in pts with SCLC.Clinical trial identification: NCT05879978.