RELAX-AHF: Benefits of serelaxin observed in subgroup analyses

AMSTERDAM — Results from a new analysis of the phase 3 RELAX-AHF study demonstrate that serelaxin improved symptoms and mortality across multiple subgroups of patients with acute HF.

Additional data on the investigational drug (Novartis) were presented at ESC Congress 2013 by Marco Metra, MD, professor of cardiology at the University of Brescia, Italy.

The addition of serelaxin, also known as RLX030, to standard therapy was associated with “nominally significant” improvements in dyspnea and mortality at 6 months across all prespecified subgroups, including those with renal impairment (estimated glomerular filtration rate <50 mL/min), adults aged 75 years or older and patients with atrial fibrillation, as compared with placebo. Subgroup analyses revealed no difference in the effect of serelaxin on dyspnea relief or the incidence of CV death, HF rehospitalization or renal failure at 60 days, compared with placebo, according to the simultaneous publication in European Heart Journal.

Subgroup analyses were conducted based on age, sex, race, geographic region, estimated GFR, time from presentation to randomization, baseline systolic BP, history of diabetes, AF, ischemic heart disease, and use of cardiac devices and IV nitrates at randomization.

“The effects of serelaxin vs. placebo appeared to be similar across subgroups of patients in RELAX-AHF,” the researchers wrote in the study. However, they cautioned that the small numbers of patients in each subgroup limit statistical conclusions that can be drawn from this analysis.

The international, randomized, double blind RELAX-AHF study included 1,161 patients. The trial was designed to compare the efficacy and safety of serelaxin vs. placebo in addition to conventional therapy for the treatment of acute HF. Serelaxin was administered within 16 hours of hospitalization as an IV infusion (30 mcg/kg/day) for 48 hours in addition to conventional therapy. The study had two primary endpoints using different scales to measure reduction in dyspnea, according to a press release.

The full results were presented at the American Heart Association 2012 Scientific Sessions. Those data demonstrated that serelaxin reduced the risk for mortality by 37%, reduced HF worsening up to day 14, and decreased length of hospital stay and intensive/cardiac care unit stay. The study did not meet secondary endpoints including days alive and out of hospital up to 60 days and CV death or rehospitalization due to HF or kidney failure up to 60 days, according to the release.

For more information:

Metra M. Clinical Trial Update Hot Line I: Updates on hypertension, heart failure and diabetes. Presented at: the European Society of Cardiology Congress; Aug. 31-Sept. 4, 2013; Amsterdam.

Metra M. Eur Heart J. 2013;doi:10.1093/eurheartj/eht371.

Disclosure: Metra reports receiving consulting income from Amgen, Bayer, Daiichi Sankyo, Novartis, Servier and Trevana, and speaker honoraria from Abbott Vascular and Novartis.