Effects of SNF472, a Novel Inhibitor of Hydroxyapatite Crystallization in Patients Receiving Hemodialysis — Subgroup Analyses of the CALIPSO Trial

INTRODUCTION: Coronary artery calcium (CAC) is highly prevalent and linked with poor outcomes in patients receiving maintenance hemodialysis, and its reduction may improve patient prognosis. SNF472, a selective inhibitor of hydroxyapatite crystallization, slows CAC progression in patients receiving maintenance hemodialysis. In this analysis, we assessed the efficacy of SNF472 in prespecified patient subgroups. METHODS: In a randomized clinical trial SNF472 300 mg, SNF472 600 mg, or placebo were infused thrice weekly in 91, 92, and 91 patients receiving maintenance hemodialysis and with CAC at baseline, respectively. In prespecified subanalyses, the percent change in CAC volume score (CACvs) from baseline to week 52 in modified intention-to-treat (mITT) and per-protocol (PP) populations was calculated in the following subgroups: age, sex, diabetes mellitus, dialysis vintage, prior atherosclerotic cardiovascular disease, baseline use of non-calcium and calcium-based phosphate binders, calcimimetics, activated vitamin D, warfarin, and statins. RESULTS: In the main trial, SNF472 significantly reduced CACvs progression compared with placebo (11% versus 20% mITT analyses; P = 0.016; 8% vs. 24% PP analyses; P < 0.001). Treatment differences for CACvs progression were similar across all subgroups, and all interaction P values were non-significant in mITT and PP analyses. CONCLUSIONS: SNF472 treatment for 52 weeks reduced CACvs progression compared with placebo in a broad range of patients receiving maintenance hemodialysis. Future studies will determine the impact of SNF472 on cardiovascular events in this population.