FDA rejects Acer's rare disease drug, asks for new trial — shares crater
Acer Therapeutics’ bid to repurpose celiprolol — a beta-blocker on the market for hypertension — as a treatment for a rare, inherited connective tissue disorder has hit a severe setback. The Newton, Massachusetts-based company on Tuesday said the FDA rejected the drug and has asked for another clinical trial.
The company’s shares $ACER cratered nearly 77% to $4.47 in Tuesday morning trading.
The drug, branded as Edsivo, is under development for vascular Ehlers-Danlos syndrome (vEDS) — a rare disorder caused by mutations largely in the COL3A1 gene, which causes arterial dissections and ruptures that can lead to an early death. It is estimated to affect between 1 in 50,000 and 1 in 200,000 people, and there are no treatments approved to treat it.
The company submitted an application to market the drug based on a small, 54-patient study — the Beta-Blockers in Ehlers-Danlos Syndrome Treatment (BBEST) — which was designed to show the drug could prevent arterial dissections and ruptures in vEDS patients. The trial tested the drug against a placebo and was stopped early as celiprolol was working well; patients given the drug, compared with no treatment, saw a reduction in arterial events, such as rupture or dissection, by threefold. However, the study was underpowered. Researchers acknowledged that they did not “reach our target number of patients”.
In April, Paris vEDS Patient Registry Data was published in the Journal of the American College of Cardiology. It “described the long-term outcome of 144 COL3A1+ vEDS patients, most of whom (~90%) were treated with celiprolol and monitored for up to 20 yrs (median 5.3 yrs). Key data highlights include lower rates of mortality and arterial complications in this patient group than that expected from the natural history of the disease. Celiprolol-treated patients had an 80.7% survival rate at ~11 yrs vs 48.5% for those not treated,” Needham’s Serge Belanger wrote in a note.
Belanger was optimistic the drug would win approval, and estimated a target market opportunity between $200 million and $400 million, based on expected Edsivo annual pricing of $100,000-$200,00 per patient.
On Tuesday, Acer chief Chris Schelling said the company is expected to respond to the FDA in the third quarter.