July 17 (Reuters) - Drugmaker Ardelyx said on

Wednesday that it has filed a lawsuit against the U.S.

Department of Health and Human Services and the Centers for

Medicare and Medicaid Services (CMS) over their plan to include

its kidney disease drug in the Medicare payment bundle system.

The lawsuit claims that CMS's plan to include the drug,

Xphozah, along with all other oral-only phosphate lowering

therapies in the End-Stage Renal Disease Prospective Payment

System (ESRD) will "significantly and negatively impact patient

choice of and timely access to important medications."

ESRD is a payment system to reimburse the facilities that

provide renal dialysis services.

Ardelyx ( ARDX ) claims drugs like Xphozah and other similar

therapies are not administered by dialysis providers and cannot

be taken during the delivery of maintenance dialysis.

Xphozah was approved in the US last year to treat high

phosphate levels in patients with chronic kidney disease.

The CMS updated regulations to include oral-only end-stage

renal disease drugs and therapies into the bundled payment

beginning January 1, 2025.