Safety, tolerability, and drug-drug interactions of NYX-783 and oxycodone in persons using opioids recreationally:...

Novel treatments are needed for opioid use disorder (OUD). NYX-783, an NMDA positive allosteric modulator, affects synaptic plasticity and learning, key processes in. Although prior preclinical and studies in healthy humans have established its safety and tolerability, studies are needed in the context of opioid use.

Nine men who used opioids recreationally and passed a safety session were enrolled in inpatient study. Participants received single doses of NYX-783 (50mg, 150mg) and placebo and in combination with two oxycodone doses (15mg, 30mg), across six inpatient drug-drug interaction (DDI) sessions in a randomized, double-blind, crossover design. The primary endpoints included cardiovascular and respiratory safety, tolerability, and pharmacokinetics.

No severe nor serious adverse events were reported and 85 % of adverse events were mild. NYX-783 reduced oxycodone's calmative effects (p < .0005). There was no effect of NYX-783 on feeling drug effect and high, nor wanting, liking, or disliking the drug. For the DDI sessions, there was no significant timepoint-by-NYX-783-by-oxycodone interaction for pulse, systolic & diastolic blood pressure, temperature, pupillary dilation, subjective drug effects, nor electrocardiogram's segments. There was a significant timepoint-by-NYX-by-oxycodone interaction for plasma NYX plasma levels (F = 3.19; DF = 8; p = 0.003) in which NYX levels were significantly higher when combined with 30mg of oxycodone vs. 15mg of oxycodone (p < 0.0001).

NYX-783's tolerability, safety, capacity to reduce oxycodone's calmative effects and benign DDI profile offers support for future, larger (i.e., Phase 1B/2A) trials specifically targeting its safety and therapeutic potential in OUD.