AstraZeneca is paying Ardelyx $35 million up front for exclusive global rights to the latter’s NHE3 (sodium-hydrogen antiporter 3) inhibitor program, including lead candidate RDX5791, which is ready to start in Phase II trials for preventing sodium overload in end-stage renal disease (ESRD) and chronic kidney disease (CKD). NHE3 plays a key role in the absorption of sodium in the intestine, and Ardelyx’ lead compound has already been evaluated in a Phase II study in constipation-predominant irritable bowel syndrome.
Under terms of the agreement Ardelyx could receive another $237.5 million in development milestones, plus launch and commercialization payments and double-digit sales royalties. The firm will conduct the clinical Phase II studies, but AstraZeneca will assume all development costs. Ardelyx retains an option to co-promote RDX5791 in the U.S.
RDX5791 is a minimally-absorbed, orally administered compound that is believed to decrease the absorption of dietary sodium, and divert sodium excretion from the kidney to the feces. In addition to developing the drug for the c-IBS, ESRD, and CKD indications, AstraZeneca and Ardelyx will evaluate potential applications of NHE3 inhibitors for other diseases resulting from sodium and fluid overload.
Founded in 2007, Ardelyx is focused on developing drugs that correct mineral metabolism imbalance and metabolic disorders, by modulating the function of specific transporters, channels, and receptors located on the gastrointestinal tract epithelium. The firm’s preclinical pipeline includes an intestinal NaP2b phosphate transporter inhibitor for treating phosphorus disorders associated with ESRD and CKD, a nonsystemic TGR5 stimulator designed to help restore glucose control in type 2 diabetes, and nonsystemic colonic potassium channel openers as potential treatments hyperkalemia in CKD/ESRD patients.