Relypsa will report new and updated analyses from several trials evaluating Veltassa (patiromer for oral suspension) in treating hyperkalemia, a serious complication in patients with chronic kidney disease (CKD) who are being treated with renin-angiotensin-aldosterone system inhibitors.

The presentations will take place at the American Society of Nephrology‘s (ASN) Kidney Week 2016, set for Chicago on Nov. 15–20.

Hyperkalemia, or usually elevated blood potassium levels, is a potentially life-threatening condition predominantly seen in patients with stage 3 or worse chronic kidney disease (CKD), being treated with renin-angiotensin-aldosterone system (RAAS) inhibitors, and who might also have diabetes, heart failure, or both.

At ASN, Matthew R. Weir, MD, a professor and director of the Division of Nephrology, University of Maryland School of Medicine, will present the poster “Aldosterone, renin and blood pressure during patiromer treatment of hyperkalemia in CKD.”  It details a post-hoc analysis of OPAL-HK (NCT01810939), a Phase 3 pivotal clinical trial that evaluated the efficacy and safety of Veltassa in 243 patients with hyperkalemia and CKD, being treated with renin angiotensin aldosterone system (RAAS) inhibitors.

The study assessed the effects of Veltassa on potassium, aldosterone, plasma renin activity and blood pressure levels. In the trial, 243 patients with moderate to severe hyperkalemia and normal potassium levels at baseline went through a four-week  Veltassa and RAAS treatment phase, followed by a 107-patient, randomized eight-week withdrawal phase. Results showed that those who continued with Veltassa treatment maintained reductions in potassium levels more effectively than those who switched to placebo.

Dr. Weir will also present the poster, “Evaluation of potential pharmacodynamic interactions with antihypertensive drugs given concomitantly with patiromer,” using data from a pooled analysis of the Phase 2 AMETHYST-DN (NCT01371747) and Phase 3 OPAL-HK clinical trials, evaluating adverse pharmacodynamic interactions after initiation of Veltassa in patients being treated with blood pressure drugs.

AMETHYST -DN was a randomized Phase 2 trial involving 306 patients with CKD, hyperkalemia, hypertension and type 2 diabetes. All were treated with RAAS inhibitors prior to and during the trial. Patients were classified according to their baseline serum potassium levels into mild (5.0 to 5.5 mmol/L; 222 patients) or moderate (greater than 5.5 mmol/L; 84 patients) hyperkalemia groups.

Patients received Veltassa twice daily for 52 weeks in three different doses: 4.2 g, 8.4 g, or 12.6 g for patients with mild hyperkalemia, and 8.4 g, 12.6 g, or 16.8 g for those with moderate hyperkalemia. As reported in July 2015, four weeks after treatment, serum potassium levels had decreased in all patients and dose regimens evaluated, especially in patients with moderate hyperkalemia.

At the trial’s end, 80% of the patients had normal potassium levels (between 3.5 and 5).  But when patients stopped the treatment, researchers reported, their serum potassium levels increased and hyperkalemia recurred within eight weeks.

In both trials, treatment with Veltassa was generally well-tolerated, with no treatment-related serious adverse events or death, a review reported.

Three additional posters will be focused on the impact of hyperkalemia:

• One will report the results of a meta-analysis that included 419,000 people with hyperkalemia and that assessed the relationship between blood potassium levels, death rates, and end-stage renal disease.
• Another will be focused on an analysis assessing the association between blood potassium levels, hospitalization, mortality, and emergency room visits in patients on hemodialysis, and how these outcomes were impacted by the day of the week.
• Finally, a presentation will highlight the results of an analysis showing that the cost of healthcare rises exponentially as CKD progresses to later stages.

Further details of all presentations are available here.

Hyperkalemia, or usually elevated blood potassium levels, often strikes in CKD and heart failure patients without warning, and can cause abnormal heart rhythms.