As reported in the Journal of Clinical Oncology by Gautschi et al, final results of the registrational phase I/II LIBRETTO-001 trial showed continued benefit of selpercatinib in patients with RET fusion–positive non–small cell lung cancer (NSCLC).
Study Details
The primary analysis of the trial resulted in approval of selpercatinib in this setting. In the trial, 247 patients with prior platinum-based chemotherapy and 69 treatment-naive patients received selpercatinib in 28-day continuous cycles of 20 mg once daily to 240 mg twice daily during dose escalation and at the recommended phase II dosing of 160 mg twice daily until disease progression or unacceptable toxicity. The final report represents an additional 19 months of follow-up since the primary analysis.
Key Findings
Objective response rates were 62% for pretreated patients and 83% for treatment-naive patients, with median response durations of 31.6 months and 20.3 months. Median progression-free survival was 26.2 months for pretreated patients and 22.0 months for treatment-naive patients. Median overall survival was 47.6 months for pretreated patients and was not reached for treatment-naive patients. On a 3-year landmark estimate, 57% of pretreated and 66% of treatment-naive patients were alive.
Among 26 patients with measurable central nervous system (CNS) metastases at baseline, the CNS objective response rate was 85%, with a median CNS response duration of 9.4 months and a median CNS progression–free survival of 11.0 months.
The safety profile of selpercatinib was consistent with previous reports.
The investigators concluded: “With substantial additional follow-up, selpercatinib continued to show durable responses and intracranial activity, with a manageable safety profile in patients with RET fusion–positive NSCLC.”
Alexander Drilon, MD, of Memorial Sloan Kettering Cancer Center and Weill Cornell Medical Center, New York, is the corresponding author of the Journal of Clinical Oncology article.
Disclosure: The study was supported by Loxo Oncology, a wholly owned subsidiary of Eli Lilly and Company. For full disclosures of the study authors, visit ascopubs.org.
