MHRA Validates Eisai’s Taletrectinib for ROS1-Positive Lung Cancer

Eisai has reached another regulatory milestone for taletrectinib after the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) validated the Marketing Authorisation Application (MAA) for the treatment of adults with advanced ROS1-positive (ROS1+) non-small cell lung cancer (NSCLC). The application was submitted through the UK’s International Recognition Pathway (IRP), which supports accelerated regulatory review by considering assessments from trusted international regulators.

The validation confirms that the application is complete and allows the MHRA to begin its formal review to determine whether taletrectinib should receive marketing authorization in the United Kingdom.

The filing follows validation of the drug’s MAA by the European Medicines Agency (EMA) in March 2026, while additional regulatory submissions are planned in Canada and other territories covered under Eisai’s licensing agreement.

Oral ROS1 inhibitor addresses an unmet need

Taletrectinib is an oral, central nervous system (CNS)-active ROS1 tyrosine kinase inhibitor developed for patients with locally advanced or metastatic ROS1+ NSCLC. Approximately 2% of patients with NSCLC harbor ROS1 gene rearrangements, and nearly one-third present with brain metastases at diagnosis, making durable systemic and intracranial disease control a key treatment goal.

Lung cancer remains one of the leading causes of cancer-related mortality worldwide. In the UK alone, approximately 50,200 new lung cancer cases are diagnosed annually, with NSCLC accounting for 80% to 85% of cases.

The therapy has already secured regulatory approvals in the United States, China, and Japan. The U.S. Food and Drug Administration approved taletrectinib in June 2025 for adults with locally advanced or metastatic ROS1+ NSCLC.

TRUST studies support regulatory submission

The UK application is supported by data from the pivotal Phase 2 TRUST clinical program, including TRUST-I (NCT04395677) conducted in China and the global TRUST-II (NCT04919811) study. Together, the two single-arm trials enrolled more than 360 patients with advanced ROS1+ NSCLC to evaluate the efficacy and safety of taletrectinib.

Updated pooled results presented in April 2026, together with updated findings from TRUST-I, strengthened the drug’s efficacy and safety profile after longer patient follow-up. Although the current announcement did not disclose new efficacy data, the accumulated evidence from both studies forms the basis of ongoing regulatory reviews across multiple regions.

Expanding global access

Eisai licensed exclusive commercialization rights for taletrectinib from Nuvation Bio in January 2026 across Europe, the Middle East, North Africa, Russia, Turkey, Canada, Australia, New Zealand, Southeast Asia, and India, extending the therapy’s potential global reach outside the United States, China, and Japan.

Commenting on the regulatory progress, Terushige Iike, Chief Business Officer of Eisai, said the UK submission marks another important step in expanding global access to taletrectinib. He added that the company believes the therapy has the potential to provide meaningful clinical value based on the efficacy and safety observed in clinical studies and will continue working closely with the MHRA throughout the review process.

Path Forward

With regulatory reviews now underway in both the UK and Europe, taletrectinib continues to advance toward broader international availability. Positive decisions from the MHRA and EMA would expand treatment options for patients with advanced ROS1-positive NSCLC, particularly those at high risk of central nervous system disease progression.

Reference

Marketing Authorisation Application for Taletrectinib for the Treatment of Advanced ROS1-Positive Non-Small Cell Lung Cancer Validated in the United Kingdom