Renibus Therapeutics has dosed the first subject in the Phase III PROTECT clinical trial of RBT-1 (stannic protoporfin/iron sucrose), a preconditioning agent, in individuals who undergo cardiothoracic surgery.

The double-blind, randomised, placebo-controlled trial is designed to assess the effect of RBT-1 in cutting down the risk of postoperative complications following cardiac surgery.

It will enrol nearly 400 participants at around 35 sites in the US and Canada.

A composite hierarchy based on severity utilising the Win-Ratio or Finkelstein-Schoenfeld method is the trial’s primary endpoint.

Time on the ventilator, blood product requirements, development of atrial fibrillation, delirium, hospital stay duration, cost-effective analyses and safety are the trial’s secondary and exploratory objectives.

Top-line data from the PROTECT study are anticipated in mid-2025 with the submission of a new drug application (NDA) slated for 2026.

A fixed-dose combination product, RBT-1 should be administered intravenously for one to two hours, 24 to 48 hours before the surgical procedure.

In a completed Phase II trial, the agent showed positive data in primary and several secondary endpoints, offering shorter ICU time, patient recovery time and fewer hospital readmissions. 

Renibus co-CEO Frank Stonebanks said: “With our pivotal trial now underway in our PROTECT programme, we are considering ways to expand the opportunity with RBT-1 across a wide spectrum of procedures and post-operative complications, including potentially transplant surgeries, TAVR's (trans aortic valve replacements) and thoracic aortic aneurysms. 

“We believe that RBT-1 has broad ‘pipeline-in-a-product’ potential, and we look forward to executing well in Phase III and bringing our product to patients in need.”