Medicine company Eli Lilly and Company (NYSE: LLY) on Monday reported positive topline data from the Phase 3 LIBRETTO-432 trial evaluating Retevmo (selpercatinib) as adjuvant therapy in patients with stage II–IIIA RET fusion-positive non-small cell lung cancer.

The trial met its primary endpoint, demonstrating a highly statistically significant and clinically meaningful improvement in investigator-assessed event-free survival versus placebo, reducing the risk of disease recurrence or death. Overall survival trended in favour of selpercatinib but remains immature, with few events recorded at the time of analysis. Safety profile was generally consistent with prior studies in the selpercatinib development programme.

LIBRETTO-432 is the first randomised Phase 3 study assessing a selective RET kinase inhibitor in the adjuvant setting for this population. Study enrolled 151 patients globally in a double-blind, controlled design, randomised 1:1 to receive selpercatinib or placebo following surgery or radiotherapy with curative intent and other adjuvant therapy where indicated.

Non-small cell lung cancer represents approximately 85% of lung cancer diagnoses in the United States, with around 30% of patients presenting with stage IB–IIIA disease. RET fusions occur in one to two percent of cases, underscoring the importance of genomic testing at diagnosis and throughout disease management.