The US Food and Drug Administration (FDA) Cardiovascular and Renal Drugs Advisory Committee (CRDAC) voted against approval of Novartis' RLX030 (serelaxin) for the treatment of acute heart failure (AHF).

Data presented at advisory committee meeting included phase II and III efficacy and safety data from the RLX030 clinical development programme, including the pivotal phase III RELAX-AHF study. In this study RLX030 improved the symptoms of acute heart failure (AHF) through reducing the rate of worsening heart failure, a measure of symptom deterioration that requires intensification of therapy.

"Recognising the urgent patient need, today we presented what we believe to be a persuasive picture of the evidence for RLX030 so far - compelling results from our Phase II and III trials with no significant safety concerns," said Tim Wright, Global Head of Development, Novartis Pharmaceuticals. "The discussion provided important information that we will address with the FDA as it completes its review. In the meantime we'll continue to drive our robust clinical trial programme and build upon the already established body of evidence."

RLX030 is under review to improve the symptoms of AHF through reduction of the rate of worsening of heart failure. Its proposed administration is in addition to conventional therapies, as a 48-hour infusion in the hospital during an AHF episode. The recommendation of the advisory committee will be considered by the FDA in its review of the Biologics License Application (BLA) for RLX030, but the FDA is not bound to follow them. The FDA makes the final decision on approvals of new treatments.

RLX030, a relaxin receptor agonist, is a recombinant form of a naturally occurring hormone (human relaxin 2) present in both men and women which rises in women during pregnancy to help the body cope with the additional cardiovascular demands.RLX030 has multiple effects including relaxing the blood vessels and reducing fluid buildup. Some evidence also suggests it can reduce damage to heart and vital organs, which may be of particular importance when considering the cascade of damage that occurs during an AHF episode.

RLX030 was granted Breakthrough Therapy (BT) designation status by the FDA in June 2013 for the ongoing development programme. The BT designation is independent of the BLA currently under review and its corresponding FDA action date. The ongoing development programme includes RELAX-AHF-2, a global, phase III outcomes study of more than 6,300 patients, of which approximately 1,000 will be from the US. The study began recruiting in 2013; results are expected in 2016 and will add to the current body of evidence for RLX030.

Heart failure (HF), when the heart is unable to pump enough blood throughout the body, is a significant and growing public health concern, substantially impacting quality of life for an estimated 5.1 million Americans. AHF can occur in people who have never had HF before or when patients with chronic HF suffer critical episodes where symptoms become worse and urgent hospital treatment is required. As an AHF episode approaches, patients become increasingly more breathless, incapacitated, and may rapidly gain weight due to fluid build-up in the body, which is often compared to the sensation of drowning due to fluid in the lungs. Every episode results in a downward spiral of worsening health and a cascade of damage to vital organs, such as the heart, kidneys and liver, which decreases the chance of the patient surviving another episode.