Aptinyx Reports Positive, Statistically Significant, Top-line Data From Phase 2 Study of NYX-783 in Patients With Post-Traumatic Stress Disorder

Aptinyx Inc. (Nasdaq: APTX), a clinical-stage biopharmaceutical company developing transformative therapies for the treatment of brain and nervous system disorders, today announced positive results from the first Phase 2 study of its novel NMDA receptor modulator, NYX-783, in 153 patients with post-traumatic stress disorder (PTSD). In the Phase 2 study, NYX-783 demonstrated statistically significant and clinically meaningful efficacy results and a favorable adverse event and tolerability profile. Based on these results, the company expects to initiate a pivotal study in 2021.

“Post-traumatic stress disorder is one of the most complex and difficult-to-treat psychiatric conditions due to a host of debilitating symptoms,” said Murray Stein, MD, MPH, FRCPC, Distinguished Professor of Psychiatry and Public Health and Vice Chair for Clinical Research in Psychiatry at the University of California San Diego and a consultant to Aptinyx. “It is encouraging to see such positive effects with NYX-783 in this study, especially given the relatively short duration of treatment. Although few drugs have shown efficacy in PTSD, this study of NYX-783 has demonstrated preliminary evidence of clinically meaningful effect along with excellent tolerability. These data position NYX-783 as a promising therapeutic candidate moving into further clinical development, which is welcomed news for the underserved patients currently living with PTSD.”

The primary objective of the first-in-patient study was achieved as both dose levels studied (10 mg and 50 mg once daily) demonstrated clinically meaningful and statistically significant improvement on the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) Arousal and Reactivity Score (p=0.040 and p=0.049 on 50 mg and 10 mg vs. placebo, respectively). This scale evaluates symptoms of PTSD such as hypervigilance, exaggerated startle response, irritability and aggression, reckless or self-destructive behaviors, and concentration and sleep disturbances. The resolution of such symptoms is highly relevant to the mechanism of action of NYX-783, which has been shown to enhance extinction learning.

Clinically meaningful improvement was also observed in the CAPS-5 Total Score within just four weeks in the 50 mg dose arm, which trended toward significance. In the intention-to-treat (ITT) population that completed Stage 1 at week four, 78% of subjects taking NYX-783 50 mg achieved a 30% improvement from baseline in the CAPS-5 Total Score, compared to 44% of subjects taking placebo (p=0.008). In the same population and time period, 50% of subjects taking NYX-783 50 mg achieved a 50% CAPS-5 Total Score improvement from baseline, compared to 26% of subjects taking placebo (p=0.044).