Touted as Potential Blockbuster, Serelaxin Flops in Late-Stage Heart Failure Trial

Study misses coprimary endpoints

Disappointing results have been reported from a global phase 3 trial investigating the efficacy, safety, and tolerability of serelaxin (Novartis) in patients with acute heart failure (AHF). The study failed to meet either of its coprimary endpoints of a reduction in cardiovascular death through day 180 or reduced worsening heart failure through day 5 when added to standard of care in patients with AHF.

Serelaxin, a relaxin receptor agonist, is a recombinant form of the naturally occurring human relaxin-2 hormone. Human relaxin-2 is present in both men and women, and elevated levels in pregnant women are thought to help the body cope with the additional cardiovascular demands during pregnancy.

The RELAX-AHF-2 trial was a randomized, double-blind, placebo-controlled study involving 6,600 patients hospitalized for AHF. The study was initiated in October 2013.

Serelaxin has had a troubled trial history, having failed in 2014 to win the approval of U.S. and European regulators, according to Reuters. Novartis pressed on in the hope of gathering enough evidence to change regulators’ minds, but the new announcement that the drug has again failed to perform appears to dash those aims.

Serelaxin was originally seen as a way for Novartis to fill the gap left by patent expirations on heart drugs such as the company’s valsartan (Diovan), which lost U.S. patent rights in 2012.

AHF is the leading cause of hospitalization in individuals older than 65 years of age. The risk of mortality after hospitalization for AHF is high, with approximately 20% of patients not surviving one year afterwards.

Sources: Novartis; March 22, 2017; and Reuters; March 22, 2017.