Study to evaluate mproUK-based sequential fibrinolysis in approximately 290 STEMI patients across 17 clinical sites in Türkiye

Thrombolytic Science, LLC (“TSI”), a clinical-stage biotechnology company developing novel thrombolytic therapies, today announced that the Turkish Ministry of Health, through the Turkish Medicines and Medical Devices Agency (TİTCK), has authorised the initiation of PROMPT-STEMI, a Phase 2 clinical trial evaluating TSI’s mutant prourokinase (mproUK)-based sequential fibrinolytic approach in patients with ST-segment elevation myocardial infarction (STEMI).

The study is sponsored by TSI Biyoteknoloji ve İlaç A.Ş. (“TSI Türkiye”), a wholly owned subsidiary of TSI. The authorisation permits the study to commence at the clinical centres included in the approved application.

“Heart attacks remain a global health crisis where rapid restoration of coronary circulation is critical to saving lives and preserving cardiac function,” said Victor Gurewich, MD, Co-founder and Chief Scientific Officer of TSI, Professor of Medicine at Harvard Medical School, and inventor of patented technologies assigned to TSI. “Restoring flow requires effective clot dissolution. Decades of research in our laboratory led to the discovery of prourokinase (proUK) and the design of mproUK, a novel fibrinolytic designed to dissolve clots with greater efficacy, target specificity, and safety than traditional agents. Through TSI, we have advanced this vital therapy into clinical trials for acute myocardial infarction in Türkiye.”

“This authorisation represents an important milestone for TSI and for the clinical development of our sequential fibrinolytic approach,” said Alexis C. Wallace, Co-founder and Chief Executive Officer of TSI. “PROMPT-STEMI will evaluate whether pharmacological reperfusion initiated at the referring hospital and continued during transfer can shift coronary reperfusion to an earlier stage of the STEMI treatment pathway—before patients reach the catheterisation laboratory for immediate angiography and PCI as clinically indicated.

PROMPT-STEMI is a prospective, randomised, open-label, blinded-endpoint Phase 2 study comparing the investigational mproUK-based reperfusion strategy with primary PCI alone. The study is expected to enrol approximately 290 patients across 17 clinical sites in Türkiye. The first site is currently targeted for activation in August 2026, subject to completion of study-drug labelling, importation and site-readiness activities.

“Receiving regulatory authorisation marks the transition of PROMPT-STEMI from planning to clinical execution in Türkiye,” said Kemal Oğuz Kalafat, MD, Chairman of the Board, and Öner Tulum, PhD, Co-Chairman of the Board, of TSI Türkiye. “Türkiye’s strong cardiovascular clinical research capabilities and extensive experience in treating acute STEMI provide an excellent environment in which to conduct this important study.”