Clinical-stage biopharmaceutical company Relypsa has enrolled its first patient in a pivotal Phase III clinical study of patiromer (RLY5016), for the treatment of hyperkalemia in patients with chronic kidney disease (CKD).
Patiromer is a high capacity non-absorbed oral potassium, designed for the management of elevated serum potassium levels.
Designed to evaluate the safety and efficacy of patiromer, the study will be conducted in two parts: Part A, the treatment phase and Part B, the withdrawal phase, under a special protocol assessment (SPA) agreement with the US Food and Drug Administration (FDA).
The single-blind, single-arm treatment phase, which will enrol 240 patients with CKD and hyperkalemia, will measure the primary endpoint as a change in serum potassium from baseline to week 4 after treatment with patiromer.
The company said subjects who respond to treatment in Part A will be eligible for Part B, designed to demonstrate the need for chronic treatment with patiromer.
Qualifying subjects will be randomised either to continue on patiromer or to receive placebo for an additional eight weeks.
The primary analysis is the between group difference in the change in serum potassium from baseline to week 4 of Part B, according to the company.
University of Maryland School of Medicine nephrology division director and trial principal investigator professor Matthew Weir said; "Having observed the efficacy and safety data from the Phase IIb study presented at ASN in 2012, I am confident this pivotal study will demonstrate the efficacy and safety of patiromer for the treatment of hyperkalemia in CKD patients receiving renin angiotensin and / or aldosterone blockade."
The company is expecting to report Phase III study results in the fourth quarter of 2013.