Sanofi punts a $200M Ardelyx deal and hands back some preclinical drugs

Sanofi ($SNY) is backing out of a collaboration with Ardelyx ($ARDX) that could have paid out nearly $200 million, returning a handful of candidate treatments for high phosphates in patients with kidney disease.

Under the initial deal, signed early last year, Sanofi paid about $1.3 million up front and promised $198 million more in exchange for the rights to some preclinical treatments for hyperphosphatemia, a condition common among patients with end-stage renal disease or chronic kidney disease. Each of the candidates is designed to block NaP2b, which transports phosphates around the body.

Now Sanofi wants out, informing its partner that it will exit the collaboration at the end of this month, Ardelyx said. The French drugmaker will hand back the undisclosed number of NaP2b inhibitors it first licensed, and Ardelyx is not due a termination payment.

The aborted deal follows a difficult run of form for Ardelyx, which pulled off a $60 million IPO last summer thanks in part to co-signers Sanofi and AstraZeneca ($AZN). In the ensuing months, a series of safety and efficacy issues clouded the future of the AstraZeneca-partnered tenapor, a treatment for high phosphates and irritable bowel disease now in mid-stage development. In June, Ardelyx bought back the rights to tenapor from its U.K. partner, paying $15 million up front and $10 million in R&D costs to nix a 2012 deal worth up to $272 million.

Now the company is completely on its own, which management says is a net positive.

"Importantly, we can now deepen our understanding of NaP2b effects utilizing our proprietary research capabilities, which was not fully possible under the terms of the Sanofi agreement," Ardelyx Chief Scientific Officer Jeremy Caldwell said in a statement.

The Freemont, CA, biotech's second major bet is RDX022, which began clinical development this year as a treatment for high levels of potassium, or hyperkalemia. The company plans to advance RDX022 through the FDA's 505(b)(2) pathway, which allows new products to use data from similar, already-approved drugs in their applications. That should allow Ardelyx to effectively skip Phase II, the company believes, and management plans to get RDX022 into late-stage studies by the second half of 2016.

- read the statement