Eli Lilly and Company has announced positive topline results from its Phase III LIBRETTO-432 trial evaluating Retevmo (selpercatinib) as adjuvant therapy in patients with early-stage RET fusion-positive Non-Small Cell Lung Cancer (NSCLC).

The global, randomised, double-blind study met its primary endpoint, showing a statistically significant and clinically meaningful improvement in investigator-assessed Event-Free Survival (EFS) compared with placebo in patients with stage II–IIIA disease. Overall survival data showed a favorable trend for selpercatinib, although the results remain immature due to a limited number of events at the time of analysis.

LIBRETTO-432 is the first randomised Phase III trial to assess a selective RET kinase inhibitor in the adjuvant setting for this patient population. The study enrolled 151 patients who were randomised 1:1 to receive either selpercatinib or placebo following definitive surgery or radiotherapy, with or without additional adjuvant treatment as indicated.

Secondary endpoints include overall survival, EFS in the overall population, central nervous system recurrence, progression-free survival on subsequent therapy, and safety and tolerability. The safety profile observed in the trial was generally consistent with previously reported data from the selpercatinib development programme.

Jacob Van Naarden, Executive Vice President and President of Lilly Oncology, said the findings reinforce the growing role of targeted therapies in early-stage lung cancer. He noted that administering precision medicines earlier in the treatment journey may deliver greater clinical impact and emphasised the importance of expanded genomic testing for patients diagnosed with early-stage disease.

Non-small cell lung cancer accounts for approximately 85 percent of lung cancer cases in the United States, with nearly 30 percent of patients presenting with stage IB–IIIA disease. RET gene fusions occur in around 1–2 percent of NSCLC cases and represent a targetable genomic alteration.

Retevmo is an oral, highly selective RET kinase inhibitor with central nervous system activity and is already approved in the United States for the treatment of adults with locally advanced or metastatic RET fusion-positive NSCLC, as identified by an FDA-approved test.