Eli Lilly (NYSE: LLY) reported at the ASCO plenary session that selpercatinib (Retevmo) cut the risk of disease recurrence or death by 83% versus placebo in early-stage RET fusion-positive non-small cell lung cancer, data that position the oral RET inhibitor to become the first targeted adjuvant therapy for a molecular subgroup that has, until now, been treated without precision medicine options after surgery. The data was presented at the 2026 ASCO Annual Meeting Plenary Session while being simultaneously published in the New England Journal of Medicine.
The results come from LIBRETTO-432, a Phase III global, randomized, double-blind, placebo-controlled trial — the first of its kind to evaluate a selective RET kinase inhibitor in the adjuvant setting. The trial enrolled 151 patients with stage IB–IIIA RET fusion-positive NSCLC following definitive surgery or radiotherapy with curative intent, with or without adjuvant chemotherapy. Patients were randomized 1:1 to selpercatinib 160 mg twice daily or placebo for up to three years. The primary endpoint was investigator-assessed event-free survival (EFS) in the primary analysis population — patients with stage II–IIIA disease (n=109).
At a median follow-up of 24 months, selpercatinib produced a hazard ratio of 0.17 (95% CI, 0.06–0.51), meeting the primary endpoint with high statistical significance. The 83% relative risk reduction in disease recurrence or death is the headline figure from that primary population. The overall safety profile was consistent with prior selpercatinib trials; the most common Grade 3 or higher adverse events were elevated AST (19% vs. 3% on placebo) and elevated ALT (17% vs. 1%), both manageable with dose modification.