OA05.05 Ifinatamab Deruxtecan (I-DXd; DS-7300) in Patients with Refractory SCLC: A Subgroup Analysis of a Phase 1/2 Study

B7 homolog 3 (B7-H3), a transmembrane immunoregulatory protein is overexpressed in several tumor types including small-cell lung cancer (SCLC). Among patients with SCLC, 65% have moderate-to-high expression of B7-H3. I-DXd is a novel B7-H3-directed antibody-drug conjugate that leverages the clinically validated deruxtecan (DXd) technology, with a plasma-stable linker and potent topoisomerase I inhibitor payload, to enhance selective tumor cell death and reduce systemic exposure of the payload. We conducted a phase 1/2 trial of heavily pretreated patients with advanced solid tumors evaluating I-DXd (Doi et al.