Durham – September 15, 2026 -- Seismic Pharmaceuticals has enrolled the first patient in RESCUE HF-CS, a global Phase 3 trial testing istaroxime as a potential first-ever approved drug for heart-failure-related cardiogenic shock, a condition with no FDA-approved treatment.
Trial to enroll 600 patients across four continents
The study will recruit approximately 600 patients at clinical sites in the United States, Europe, China and South America. It builds on four completed Phase 2 trials that enrolled more than 350 patients.
Cardiogenic shock carries high mortality despite critical care advances
The condition occurs when the heart cannot pump enough blood to meet the body's needs, cutting oxygen delivery to vital organs. It often complicates acute heart failure or other serious cardiac events, and no pharmacologic therapy has been developed specifically to treat it.
Istaroxime targets both contraction and relaxation phases of the heart cycle
Unlike conventional inotropic drugs, istaroxime is designed to improve systolic contraction and diastolic relaxation simultaneously without increasing myocardial oxygen demand. The company states it also reduces heart rate and arrhythmias, differentiating it from therapies currently used off-label for cardiogenic shock.
Harvard cardiologist calls trial a paradigm-shift opportunity
Dr. Mandeep R. Mehra of Mass General Brigham Heart & Vascular Institute, the study's principal investigator, said cardiogenic shock remains one of the most lethal conditions in cardiovascular medicine despite the absence of an approved pharmacologic therapy tailored to the syndrome. He said RESCUE HF-CS will test whether istaroxime's dual mechanism can change treatment for critically ill patients.
Trial details to be posted on clinical-trial registries
Additional information on the trial's design, eligibility criteria and participating sites will be published on ClinicalTrials.gov and other applicable registries.