Acacia Pharma has reported positive results from its Phase 2 study of APD421, used for the prevention of post-operative nausea and vomiting (PONV).

APD421 consists of a potent dopamine D2 / D3 antagonist, currently marketed for the treatment of certain psychiatric disorders, which the company has repurposed for the completely new use of the prevention and treatment of PONV.

The double-blind Phase 2 study recruited 223 surgical patients with two or more of the four established Apfel risk factors for PONV and compared three doses of APD421 with placebo.

"APD421 considerably reduced the incidence of nausea and vomiting compared to placebo."

In the trial, the primary endpoint was protection against PONV, defined as no vomiting or retching and no requirement for anti-emetic rescue medication in the first 24 hours after surgery.

The study showed that APD421 considerably reduced the incidence of nausea and vomiting compared to placebo in adult surgical patients at moderate-to-high risk of suffering from PONV.

APD421 was found superior to placebo at preventing PONV, the optimal dose approximately halving the PONV rate from 67% in the placebo group to 36%.

In addition, APD421 was well tolerated at all three dose levels, with no difference in the frequency of any adverse event for any dose of APD421 compared to placebo, and no serious adverse reactions.

Acacia Pharma CEO Julian Gilbert commented that anaesthetists seek a safe dopamine antagonist for the prevention and treatment of PONV, and APD421 appears to meet the profile.

"We therefore believe that it has the potential to become a mainstay of anti-emetic therapy and contribute greatly to the well-being of patients undergoing surgery," Gilbert added.

Gabriel Fox, Acacia Pharma chief medical officer, said the well-conducted trial in European and US centres has shown an unequivocal benefit for APD421 in patients who are the hardest to protect from post-operative sickness, those with multiple Apfel risk factors.