R&D Pipeline

Rezubio’s lead MADD therapeutic candidate, RZ-629, is a novel gut-targeted GPR40 agonist designed to deliver potent metabolic benefits with minimal systemic exposure. In multiple animal models, RZ-629 produced superior glucose lowering and body-weight reduction compared with the pharmacophore molecule alone, while avoiding the systemic liabilities—such as liver and pancreatic toxicities—that have limited prior GPR40 agonist programs.

A rat tissue-distribution study showed that nearly 100% of administered parent drug was recovered in feces, with biliary and urinary excretion each below 0.01% of dose, confirming that RZ-629 remains gut-restricted with negligible systemic exposure.

RZ-629 activates a broader, more physiological hormone response than current incretin-based GLP-1 receptor agonists. By stimulating endogenous secretion of GLP-1, GIP, PYY, and glucagon from the gut, RZ-629 mimics the body’s natural response to dietary fatty acids and shows synergy with food intake. Importantly, the induction of GIP and PYY is associated with significantly reduced gastrointestinal intolerance in rodent studies compared with GLP-1 receptor agonists, suggesting RZ-629 has a potentially more tolerable profile in patients.