A phase 1 randomized, placebo-controlled study to investigate potential interactions between ASP8062, a positive allosteric modulator of the GABA B receptor, and morphine in recreational opioid users.

In this phase 1 study, we did not observe any unexpected safety signals or notable PK interactions with concomitant morphine administration. These data suggest a potentially low risk for an increase in drug abuse- or withdrawal-related adverse events or respiratory distress in participants exposed to ASP8062 and morphine.