Relypsa sets up hyperkalemia showdown with AstraZeneca

Relypsa ($RLYP) and AstraZeneca ($AZN) are seeking to battle it out in Europe and the U.S. for their new blood disorder drugs as the biotech seeks European approval. 

This comes after the Redwood City, CA-based biotech and its EU marketing partner Vifor Fresenius Medical Care Renal Pharma submitted patiromer (aka Veltassa) to the EMA this week for the treatment of hyperkalemia--or elevated blood potassium levels. 

Relypsa's drug has already won an FDA approval back in late 2015, making it the first new treatment for the condition in half a century--although it came with a Black Box warning of interactions with oral meds.

This may change however the company is preparing a supplemental New Drug Application for an updated label (which takes around 6 months) after new trials showed it didn't interact with other treatments as much as first thought.

The drug is co-marketed in the U.S. with French Big Pharma Sanofi ($SNY), whereas Vifor will be its European partner for the drug. Analysts’ expectations currently range from peak annual sales of $200 million all the way up to $1 billion.

AstraZeneca is also hoping to get in on this market that could be worth $6 billion in total after buying ZS Pharma ($ZSPH) and its lead candidate ZS-9, a late-stage treatment for hyperkalemia, for $2.7 billion back in 2015.

ZS-9 is currently awaiting a final FDA decision for its treatment, which is expected later this year--a PDUFA goal date for the decision has been set for May 26 and comes after submitting its drug to the EMA back in January--setting up a showdown between the two treatments in the world's two largest pharma markets. 

AstraZeneca’s drug has been seen as more favorable by analysts (although ZS-9 has also come with some safety issues during testing) and there were concerns over Veltassa’s Black Box warning; if it can however have this downgraded it will likely make it a much larger rival--although all still hinges on the FDA’s final decisions in the coming weeks and months--and whether doctors will be willing in the near-term to use these new treatments ahead of older, more well-known (and cheaper) meds. 

Relypsa’s marketing application is based on Phase III data from its OPAL-HK study that showed  the drug significantly reduced and maintained control of blood potassium levels in a pre-specified sub-group analysis of patients age 65 and older with chronic kidney disease and hyperkalemia.

“The MAA submission for Patiromer represents an important milestone in our efforts to bring hyperkalemia patients in Europe a new treatment option as soon as possible,” said Stefan Schulze, CEO of Vifor. 

“Relypsa has been an excellent partner supporting the preparation of this robust submission, which is based on positive efficacy and safety results from an extensive clinical development program that included many patients from Europe.”

Relypsa is also rumored to be the subject of a potential buyout with several of the companies that unsuccessfully bid for ZS Pharma--which included Actelion--having reached out to Relypsa, according to reports earlier this month from Reuters

Relypsa was down 2.3% at 2pm EDT. 

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