The FDA has refused to accept the filing of a rare disease treatment for vascular Ehlers-Danlos syndrome (vEDS) from Acer Therapeutics.
The Newton, Massachusetts-based rare disease specialist saw its shares lose nearly 80% of their value after the knock-back of Edsivo (celiprolol) was announced yesterday.
The regulator issued a Complete Response Letter (CRL), which stated that an “adequate and well-controlled trial” was needed to determine whether celiprolol reduces the risk of clinical events in patients with vEDS.
Edsivo is being developed for vascular Ehlers-Danlos syndrome (vEDS) in patients with a confirmed type III collagen (COL3A1) mutation.
Ehlers-Danlos syndromes (EDS) are a group of rare inherited conditions that affect connective tissue. vEDS is a rare form of the condition and often considered to be the most serious. It affects blood vessels and internal organs, which can cause them to split open and lead to life-threatening bleeding.
The rejection came as a surprise to some analysts, with William Blair having previously judged the drug’s efficacy evidence base as strong. In a recent research note it said one study of 144 COL3A1+ vEDS showed increased survival benefit and reduced hospitalisation frequency for arterial events in European patients receiving long-term celiprolol therapy.
The earlier 2011 BBEST study has shown celiprolol reduced major arterial events 2.5 times over untreated controls.
The need for a new trial will set back Acer’s plans considerably, as it had been preparing to bring the therapy to market later this year.
“We remain committed to working closely with the FDA to fully understand its response,” said Chris Schelling, CEO and founder of Acer. “We expect to respond to the FDA in the third quarter of this year.”
In addition to its lead compound, the company also has ACER-001 (a fully taste-masked, immediate release formulation of sodium phenylbutyrate) to treat various inborn errors of metabolism, including urea cycle disorders (UCDs) and Maple Syrup Urine Disease (MSUD).
Also in its pipeline is osanetant, for the treatment of various neuroendocrine disorders, which it in-licensed from Sanofi in January.