Japan-based Astellas Pharma has received a grant from the US National Institutes of Health (NIH) unit to support two Phase I clinical trials of ASP8062 as a maintenance treatment for opioid use disorder (OUD).

ASP8062 is an oral small molecule GABAB receptor Positive Allosteric Modulator (PAM).

In early studies, ASP8062 was found to reduce self-administration and drug-seeking behaviour across different substances of abuse, including opioids, alcohol and cocaine. It is known to act by suppressing dopamine release from certain brain areas.

Astellas will use the NIH grant to assess the safety and efficacy of the therapeutic given along with buprenorphine (BUP)-based therapy and then morphine in two Phase I OUD trials.

A potential second phase of the grant is expected to enable a randomised, double-blind Phase II trial to evaluate the efficacy of ASP8062 in decreasing opioid use in OUD patients receiving stable BUP treatment.

Funding for the Phase I programme was awarded after an investigational new drug (IND) application was submitted to the FDA for ASP8062 in OUD in April this year.

If positive safety data is obtained in the Phase I trials, the second phase of the grant may be awarded.

Astellas Pharma Medical Specialties senior vice-president and therapeutic area head Salim Mujais said: “This is an early, but important, step in identifying a potential new approach to tackle the ever-growing opioid crisis.

“We hope to be able to contribute to the NIH strategy to identify scientific solutions and novel pharmacotherapies to deliver new treatment options for patients battling opioid addiction.”

The US Government declared opioid crisis as a national public health emergency in October 2017. In 2018, more than 46,802 deaths in the country were caused by opioid overdose.

In February, Astellas and its partner Pfizer reported positive data from the Phase III PROSPER trial of Xtandi (enzalutamide) in patients with non-metastatic castration-resistant prostate cancer (nmCRPC).