Advancing Domestic Approval of New Thrombolytic Agent Based on T-FLAVOR Trial Results: Efficacy Confirmed for Early Recanalization in Stroke Patients

The National Cerebral and Cardiovascular Center (NCVC) and Kyorin University Hospital announced the results of the 'T-FLAVOR' randomized controlled trial, conducted across 18 facilities in Japan. The study evaluated a treatment administered within 4.5 hours of stroke onset. Results showed that tenecteplase (currently unapproved in Japan) achieved a significantly higher rate of recanalization in blocked cerebral vessels compared to the currently used drug, alteplase. The findings, led by Dr. Manabu Inoue of the NCVC, were published in the online edition of JAMA Neurology on June 1, 2026. In acute ischemic stroke, rapid recanalization is critical to reducing long-term disability. While thrombolytic therapy is essential, the efficacy of alteplase is limited. Tenecteplase, a modified version of alteplase, is already approved and included in guidelines abroad. Due to the lack of this drug in Japan and the absence of corporate-led trials, an investigator-initiated study was necessary to prove its efficacy in Japanese patients, particularly given the unique domestic dosage of 0.6 mg/kg for alteplase compared to the international standard of 0.9 mg/kg. The study involved 218 patients enrolled between 2022 and 2025. The primary endpoint—early recanalization at the start of endovascular therapy—was 10.3% for the tenecteplase group versus 3.6% for the alteplase group. Safety profiles, including symptomatic intracranial hemorrhage and 90-day mortality, showed no significant differences between the groups. As tenecteplase can be administered via a single short intravenous bolus, it offers potential for simplified hospital workflows and improved emergency transport efficiency. The Ministry of Health, Labour and Welfare is currently reviewing the drug for approval.