- The disease
- A ST-elevation myocardial infarction (STEMI) is a type of heart attack in which a coronary artery is completely blocked, cutting off blood supply to part of the heart muscle. The standard treatment is primary percutaneous coronary intervention (PCI), a procedure to physically reopen the blocked artery. However, restoring blood flow itself causes a second wave of cellular damage known as reperfusion injury, which can worsen the final size of the heart attack and contribute to long-term heart dysfunction. Reducing reperfusion injury at the time of PCI is an active area of clinical investigation.
- What the asset is trying to do
- Xolatryp is a small molecule that inhibits tryptophan hydroxylase (TPH), the enzyme responsible for producing serotonin in peripheral tissues (per Nyrada company disclosures). The rationale is that serotonin released during a heart attack and subsequent PCI may contribute to the cellular damage that occurs when blood flow is restored. By blocking TPH and thereby reducing serotonin synthesis, Xolatryp is intended to limit that reperfusion-related injury. Nyrada has also disclosed, as of May 2026, that Xolatryp has shown activity in an oncology context involving anthracycline anti-tumour efficacy, though the PROTECT-MI trial is focused on the cardiac indication (per ASX announcement 2026-05-19).
- What the trial is measuring, and why it matters
- The PROTECT-MI Phase IIa trial (NCT07362446) is a randomised, double-blind, placebo-controlled study enrolling 300 STEMI patients (per ClinicalTrials.gov NCT07362446). The trial is titled "Prevention of Reperfusion Injury Outcomes Through Effective Cardioprotection Targeting Myocardial Infarction." Primary and secondary endpoints are but in reperfusion injury trials, commonly used measures include infarct size (often assessed by cardiac MRI or enzyme levels), myocardial salvage index, and cardiac function measures such as ejection fraction. The double-blind, placebo-controlled design is the standard for generating controlled evidence in this setting.
- Efficacy benchmarks in this setting
- In the STEMI reperfusion injury setting, no pharmacological agent specifically targeting this mechanism has received regulatory approval as a cardioprotective adjunct to primary PCI (per regulatory databases). Several investigational cardioprotective strategies have been studied; for example, cyclosporine administered at the time of PCI was evaluated in the CIRCUS trial (n=970) and showed no significant reduction in the primary composite endpoint of death, worsening heart failure, adverse left ventricular remodelling, or rehospitalisation for heart failure at one year compared with placebo (Cung et al, New England Journal of Medicine, 2015). Ischaemic conditioning strategies have produced variable results across large trials in this population. Any early-phase or pilot figures reported for Xolatryp are not statistically comparable to results from large, powered, randomised controlled trials in this setting.
- Commercial context
- No drug is currently approved specifically for the prevention of reperfusion injury as an adjunct to primary PCI in STEMI patients, based on publicly available regulatory approval listings (per ). Nyrada received a Notice of Allowance for a US patent for Xolatryp in May 2026 (per ASX announcement 2026-05-19). The company received an A$2.455 million R&D Tax Incentive Rebate in May 2026 (per ASX announcement 2026-05-28). The PROTECT-MI trial is described in Nyrada's public materials in the context of its cardiology programme; whether this is the company's sole or lead asset across all programmes is . No disclosed partnering or licensing deal terms for Xolatryp in the cardiac indication have been identified in the provided announcements.