AstraZeneca and Ardelyx have entered into a worldwide exclusive licensing agreement for Ardelyx’s NHE3 inhibitor programme for complications associated with end-stage renal disease (ESRD) and chronic kidney disease (CKD).

NHE3 is the sodium-hydrogen antiporter 3, a protein essential in the absorption of sodium in the intestines. The programme also includes the phase 2-ready lead compound RDX5791, designed for the treatment of complications associated with end-stage renal disease (ESRD) and chronic kidney disease (CKD)

The companies plan to develop RDX5791 for use in ESRD, CKD and irritable bowel syndrome (IBS-C), and aims to evaluate possible development in other diseases that are a consequence of sodium and fluid overload.

AstraZeneca CVGI Innovative Medicines vice president and head Gunnar Olsson said the licensing agreement will enable the development of new medicines for people with renal complications, including those resulting from diabetes.

"With a novel mechanism of action, RDX5791 has the potential to have a major impact on how doctors treat these patients," Olsson added.

As a part of the agreement, AstraZeneca will make a $35m upfront payment along with development milestones of $237.5m and milestones related to launch and commercialisation, besides double-digit royalties.

AstraZeneca is expected to assume the subsequent development costs, and Ardelyx, which will conduct phase 2 trials, has secured an option to co-promote the product in the US, subject to agreed limitations.

Ardelyx CEO Mike Raab said, "RDX5791 is our first clinical example of how our technology can be used to develop non-absorbed, small molecule therapeutics. We are delighted that AstraZeneca recognizes the potential of this compound."

Ardelyx has evaluated RDX5791 for its ability to divert sodium absorption in the gastrointestinal tract in a phase 2a clinical trial in constipation-predominant IBS-C, and in two phase 1 studies in healthy subjects.