INDIANAPOLIS, Indiana, May 31, 2026
Eli Lilly and Company has announced groundbreaking results from the pivotal Phase 3 LIBRETTO-432 trial, demonstrating that Retevmo® (selpercatinib) reduced the risk of disease recurrence or death by an impressive 83% when used as adjuvant therapy in patients with early-stage RET fusion-positive non-small cell lung cancer (NSCLC). The landmark findings were simultaneously presented during the prestigious ASCO 2026 Plenary Session and published in The New England Journal of Medicine, marking a significant advancement in precision oncology for lung cancer. The results establish RET fusion-positive disease alongside EGFR-mutated and ALK-positive lung cancer as molecularly defined populations that can achieve substantial benefit from targeted treatment in the early-stage setting. The study also reinforces the growing importance of comprehensive biomarker testing at diagnosis to identify patients who may benefit from highly effective targeted therapies before cancer recurrence occurs.
Phase 3 LIBRETTO-432 Delivers Landmark Disease-Free Outcomes
LIBRETTO-432 is the first randomized Phase 3 study evaluating a selective RET kinase inhibitor as adjuvant therapy following curative-intent treatment in patients with RET fusion-positive NSCLC. The global trial enrolled 151 patients with Stage IB-IIIA disease, who were randomized to receive either Retevmo or placebo for up to three years following surgery, radiation therapy, and other standard treatments when indicated.
The study successfully met its primary endpoint, showing a highly significant improvement in event-free survival (EFS) among patients receiving Retevmo. In the primary analysis population consisting of Stage II-IIIA patients, treatment reduced the risk of recurrence or death by 83%, with a hazard ratio of 0.17. At 24 months, the EFS rate reached 92% for patients treated with Retevmo compared with 61% for those receiving placebo. Across the overall study population, results remained consistent, with a 24-month EFS rate of 94% versus 70%, respectively. Notably, the median event-free survival had not yet been reached in the Retevmo arm, highlighting the durability of clinical benefit achieved with targeted RET inhibition.
Precision Medicine Continues to Transform Early Lung Cancer Care
Advertisement
The LIBRETTO-432 findings represent a major milestone in the evolution of precision medicine for lung cancer. Historically, patients with RET fusion-positive tumors have faced a substantial risk of disease recurrence even after successful surgery. Unlike patients with EGFR mutations or ALK rearrangements, however, they lacked a proven targeted adjuvant therapy capable of reducing that risk.
Researchers noted that the magnitude of benefit observed with Retevmo supports routine comprehensive genomic profiling for all newly diagnosed lung cancer patients, regardless of disease stage. By identifying actionable biomarkers such as RET fusions at diagnosis, clinicians can now consider highly personalized treatment strategies designed to prevent recurrence and improve long-term outcomes. The data further validate the role of molecular testing as an essential component of modern oncology care and highlight the growing impact of targeted therapies beyond advanced metastatic disease settings.
Strong Safety Profile Supports Potential New Standard of Care
The safety findings from LIBRETTO-432 were generally consistent with the established profile of Retevmo observed in previous studies involving advanced RET-driven cancers. The most common Grade 3 or higher adverse events included elevations in liver enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which were largely manageable through dose adjustments and monitoring. No unexpected safety signals emerged during the trial, supporting the feasibility of long-term treatment in patients with potentially curable disease.
Lilly believes the compelling efficacy and manageable safety profile demonstrated in LIBRETTO-432 position Retevmo as a potential new standard of care for patients with early-stage RET fusion-positive NSCLC. The company plans to submit the data to regulatory authorities worldwide to support expanded approvals. As targeted therapies continue moving into earlier stages of cancer treatment, the LIBRETTO-432 results represent one of the most important advances in RET-positive lung cancer to date, offering new hope for patients seeking to reduce the risk of recurrence and improve long-term survival outcomes following curative treatment.
Source: Eli Lilly press release
