PHILADELPHIA – Among patients with chronic kidney disease with resistant hypertension, coadministration of patiromer enables more patients to stay on spironolactone, Bryan Williams, MD, of University College London, said at the scientific meeting of the Heart Failure Society of America.
Having the potassium-binding polymer on board allowed for more persistent use of spironolactone, both in the subgroup of patients with heart failure, and those without, he said in a late-breaking clinical trials session.
In the international, phase 2 AMBER (Spironolactone With Patiromer in the Treatment of Resistant Hypertension in Chronic Kidney Disease) trial, 295 patients with chronic kidney disease (estimated glomerular filtration rate from 25 to 45 mL/min per 1.73 m2) were randomly assigned to treatment with spironolactone either placebo (148) or patiromer (147).
(Lancet 2019 Sep 15; doi: 10.1016/S0140-6736(19)32135-X)., for a significant between-group difference of 19.5% (P less than .0001). In addition, blood pressure lowering was significantly greater in the patiromer (–11.7 mm Hg) than in the placebo (–10.8 mm Hg) group. Results of the AMBER trial were published concurrently with Dr. Williams’ presentation
While spironolactone is a “highly effective” drug, studies supporting guideline recommendations for its use in resistant hypertension have largely excluded patients with advanced chronic kidney disease because of increased risk of developing spironolactone-induced hyperkalemia, Dr. Williams told attendees. It remains unclear, however, whether coadministration of patiromer will improve long-term outcomes. Also, many placebo-treated patients in AMBER were able to continue on spironolactone without the help of patiromer, prompting one attendee to question whether there was a smarter way to target the drug, rather than treating all patients up front.
“I don’t think it’s going to be easy to say, ‘this patient’s going to respond, and this patient’s not going to respond,’ ” Dr. Williams said in response, “but at least we have an opportunity to try now in a group of patients who simply may be denied treatment because of a perception that it is difficult to use spironolactone in them.”
That perception is actually not unreasonable, he added, given that 66% of patients in the placebo group in AMBER developed hyperkalemia, suggesting that spironolactone is “not an easy drug to use” in chronic kidney disease patients.
John Teerlink, MD, of the San Francisco VA Medical Center, said the AMBER study is “another building block” in a series of developments of enabling therapies.
“I think it’s a great message for all of us to begin thinking about other therapies we can use to help modify our use of these potential life-saving therapies,” he said in a panel discussion of the results.
Patiromer’s impact on longer-term outcomes is the focus of DIAMOND, a phase 3, randomized, placebo controlled trial that is currently recruiting. DIAMOND will determine whether giving patiromer to patients who developed hyperkalemia on renin-angiotensin-aldosterone system (RAAS) inhibitors decreases cardiovascular deaths and hospitalizations, by virtue of enabling continued RAAS inhibitor use.
Funding for AMBER came from Relypsa, which markets patiromer (Veltassa). Dr. Williams reported consulting for Relypsa during the conduct of the study, along with disclosures outside the scope of the AMBER study (Daiichi Sankyo, Pfizer, Novartis, Servier, Boehringer Ingelheim, and Vascular Dynamics).
SOURCE: Williams B. HFSA 2019.