Two pivotal trials with consistent findings
The FIDELITY analysis combined data from the FIDELIO-DKD trial, reported in 2020, and from the FIGARO-DKD trial that was first reported during the current congress as well as in a simultaneous report published online.
Results from the two trials were very consistent, although the primary endpoint in FIDELIO-DKD was a composite measure of renal disease with the combined cardiovascular disease metric a secondary endpoint, while this got flipped in FIGARO-DKD which had the cardiovascular disease composite as its primary endpoint as the combined renal outcomes as a secondary endpoint.
In addition to showing a consistent, significant reduction in both combined cardiovascular disease events and in the specific endpoint of hospitalization for heart failure, the two trials also showed a consistent benefit for slowing renal disease progression, including significantly fewer patients developing end-stage kidney disease. In the combined FIDELITY analysis, treatment with finerenone cut the incidence of end-stage kidney disease by a significant 20% compared with placebo, and by an absolute reduction of 0.6%.
Another common finding was a relatively low incidence of hyperkalemia compared with what’s usually seen using a steroidal MRA, spironolactone or eplerenone. In the combined analysis treatment with finerenone produced a 14% incidence of any hyperkalemia compared with 7% among placebo-treated patients, and the rate of patients stopping their treatment because of hyperkalemia was 1.7% on finerenone and 0.6% on placebo.
“Finerenone is much better tolerated” than the steroidal MRAs in causing clinically significant hyperkalemia, noted Dr. Pitt. “There are a lot of misconceptions” about the potassium-raising potential of MRAs, and “people get frightened” by the potential. Spreading the message of finerenone’s relative safety “will take a lot of education,” he acknowledged. Routine monitoring of potassium levels is a key step to minimizing the risk for hyperkalemia when using finerenone, he added.
Suggested benefit from combination treatment
Another intriguing observation from FIDELITY derived from the fact that roughly 7% of enrolled patients were also on treatment with a sodium-glucose cotransporter 2 (SGLT2) inhibitor at entry, and about 7% were on treatment with a glucagon-like peptide-1 (GLP-1) receptor agonist, and in both subgroups the incidence of the composite cardiovascular disease endpoint appeared to suggest additive effects of agents from either of these classes when combined with finerenone. Although the numbers of patients on combined treatment were too low to show a definitive result, “our expectation is that we will see an additive effect,” said Dr. Pitt. Ideally, patients with T2D and CKD “should be on both” an SGLT2 inhibitor and finerenone, he predicted.
SGLT2 inhibitors have now been embraced as a key treatment for patients with T2D or with heart failure with reduced ejection fraction, and the preliminary data suggest that combining these agents with finerenone can provide additional benefit, agreed Dr. Itchhaporia. Aside from the need for more evidence to prove this, there are also practical considerations of “How do we pay for all these fantastic therapies?” She expressed optimism that cost-benefit analyses will eventually show that the additive benefits justify the added cost.
Based largely on results from FIDELIO-DKD, finerenone received marketing approval from the Food and Drug Administration in July 2021 for the indication of treating patients with T2D and chronic kidney disease.
FIGARO-DKD, FIDELIO-DKD, and FIDELITY were sponsored by Bayer, the company that markets finerenone. Dr. Filippatos has received lecture fees from Bayer, and has had financial relationships with Amgen, Boehringer Ingelheim, Medtronic, Novartis, Servier, and Vifor. Dr. Agarwal received travel support from and has been a consultant to Bayer and to numerous other companies. Dr. Pitt has been a consultant to Bayer and to numerous other companies. Dr. Itchhaporia had no disclosures.