Durham, North Carolina-based Seismic Pharmaceuticals has launched a global Phase III trial of istaroxime in cardiogenic shock, a life-threatening condition with no US FDA-approved pharmacological therapy.
The RESCUE HF-CS study is expected to enroll approximately 600 patients across the US, Europe, and South America. The randomized, double-blind trial is evaluating istaroxime plus standard care against placebo plus standard care in patients with SCAI Stage B or C cardiogenic shock due to acute heart failure.
Istaroxime is an intravenous therapy with a dual mechanism designed to improve both cardiac contraction and relaxation. It inhibits Na+/K+-ATPase to increase contractility while activating SERCA2a, a calcium pump involved in cardiac relaxation. The mechanism differs from conventional inotropes such as dobutamine and milrinone, which act through cAMP-dependent pathways and can increase arrhythmia risk.
The Phase III program builds on four completed Phase II trials in which more than 340 patients received istaroxime. These included the SEISMiC studies in patients with acute heart failure and pre-cardiogenic shock, as well as SEISMiC-C, which evaluated the drug in SCAI Stage C cardiogenic shock. Earlier studies, including IGNITE, established its hemodynamic activity in acute decompensated heart failure.