Increased rates of fluid retention
Although aprocitentan was generally well tolerated, the most common adverse effect was edema or fluid retention, mainly during the first 4 weeks of treatment. In the full PRECISION cohort, this adverse event occurred in 2.1% of people treated with placebo, 9.1% of those on the 12.5-mg daily dose, and in 18.4% of those on the higher dose during the initial 4-week phase of treatment.
Among all stage 3 and 4 CKD patients on aprocitentan, edema or fluid retention occurred in 21% during the first 4 weeks, and in 27% during an additional 32 weeks of treatment with 25 mg aprocitentan daily. A majority of these patients started a diuretic to address their excess fluid, with only two discontinuing aprocitentan treatment.
“Fluid retention is an issue with aprocitentan,” Dr. Bakris acknowledged. But he also highlighted than only 6 of the 162 patients with CKD required hospitalization for heart failure during the study, and one of these cases had placebo treatment. Among the five with acute heart failure while on aprocitentan, none had to stop their treatment, and two had a clear prior history of heart failure.
The companies developing aprocitentan, Janssen and Idorsia, used the PRECISION results as the centerpiece in filing for a new drug approval to the FDA, with a March 2024 goal for the FDA‘s decision. Dr. Bakris called the application “a solid case for approval.” But he added that approval will likely require that all treatment candidates first undergo testing of their heart function or fluid volume, such as a measure of their blood level of N-terminal pro-B-type natriuretic peptide, with treatment withheld when the level is too high.
The upside of aprocitentan compared with current drug options for treating resistant hypertension is that it has not appeared to cause any increase in blood potassium levels, which is an issue with the current top agent for resistant hypertension, spironolactone.
“The problem with spironolactone is the risk for hyperkalemia, which keeps us looking for something with lower risk,” commented Dr. Pradhan, a nephrologist with University Hospitals in Cleveland. Hyperkalemia is an even greater risk for people with CKD. Although the PRECISION trial identified the issue of fluid retention with aprocitentan, titrating an effective dose of a loop diuretic for treated patients may effectively blunt the edema risk, Dr. Pradhan said.
Endothelin has a potent vasoconstrictive effect and is “implicated in the pathogenesis of hypertension,” Dr. Bakris explained. Aprocitentan antagonizes both the endothelin A and B receptors. The subgroup analyses also showed that in people with CKD, treatment with aprocitentan led to roughly a halving of the baseline level of urine albumin-to-creatinine ratio, a small and stable decrease in estimated glomerular filtration rate, and a modest and stable increase in blood levels of N-terminal pro-B-type natriuretic hormone.
The PRECISION trial was sponsored by Janssen Pharmaceuticals and Idorsia Pharmaceuticals, the companies jointly developing aprocitentan. Dr. Bakris has been a consultant to Janssen, and also a consultant to or honoraria recipient of Alnylam, AstraZeneca, Bayer, Dia Medica Therapeutics, Ionis, inREGEN, KBP Biosciences, Merck, Novo Nordisk, and Quantum Genomics. Dr. Pradhan had no disclosures.