Small cell lung cancer (SCLC): At the door of targeted therapies

Small-cell lung cancer (SCLC) is a tobacco-associated neuroendocrine tumor comprising ~15% of lung cancers (~150,000 cases/year). For decades, outcomes stagnated: most patients present with extensive-stage disease, screening rarely detects early tumors, surgery is seldom feasible, and platinum–etoposide remained the first-line standard with median overall survival (OS) 80% of SCLC, enables T-cell–redirecting therapy: the bispecific T-cell engager tarlatamab improved OS to 13.6 vs 8.3 months over standard second-line chemotherapy, with manageable cytokine release syndrome and occasional ICANS. B7 homolog 3 (B7-H3, CD276), uniformly expressed across SCLC subtypes and linked to poor prognosis, is another compelling target: the antibody–drug conjugate ifinatamab deruxtecan achieved a 54.8% response rate and meaningful survival in heavily pretreated patients, earning FDA Breakthrough designation. Together, DLL3- and B7-H3–directed therapies (with additional ADCs against Trop-2 and SEZ6 in development) are redefining second-line and later care. Key next steps include optimizing sequencing/combination strategies, managing BiTE-specific toxicities, and developing predictive biomarkers. After decades of futility, SCLC is transitioning from uniform chemotherapy to a precision-medicine paradigm with cautious optimism.