Non-Opioid Therapy NYX-2925 Blocks Pain Hypersensitivity in Fibromyalgia Patients, Phase 2 Trial Shows

Non-Opioid Therapy NYX-2925 Blocks Pain Hypersensitivity in Fibromyalgia Patients, Phase 2 Trial Shows

Treatment with the new, non-opioid small molecule NYX-2925 can block hypersensitivity to pain in patients with fibromyalgia, results from an exploratory clinical study show.

The oral compound, being developed by Aptinyx, also induced statistically significant changes on neuroimaging biomarkers, fatigue, and overall function.

These top-line data from NYX-2925’s Phase 2 trial will be presented at the American College of Rheumatology (ACR) 2019 Annual Meeting, to be held Nov. 8-13 in Atlanta. The electronic poster is titled “NYX-2925 Impacts Functional and Chemical Neuroimaging Biomarkers and Patient-reported Outcomes of Pain in Patients with Fibromyalgia.”

“The opportunity to showcase these clinical data in a late-breaking presentation demonstrates their scientific importance in a field in dire need of new therapeutic options,” Norbert Riedel, PhD, president and CEO of Aptinyx, said in a press release. “Taken together, the imaging data and the clinical outcomes from this study are highly supportive of the continued development of NYX-2925 in chronic centralized pain conditions.”

NYX-2925 is designed to modulate the response of NMDA receptors, which are critical mediators of nerve cells’ communication and transmission of pain signals in the brain and spinal cord.

The safety and efficacy of this new therapy was evaluated in a randomized, placebo-controlled Phase 2 trial (NCT03249103). That study was conducted in collaboration with the Chronic Pain and Fatigue Research Center at the University of Michigan Medical School and the Women’s Health Research Program at University of Cincinnati College of Medicine.

The trial enrolled 22 right-handed women diagnosed with fibromyalgia who received once-daily doses of placebo for two weeks, followed by two weeks of once-daily treatment with 20 mg NYX-2925. After completion of the low-dose treatment, all participants took a higher dose — 200 mg — of NYX-2925 once per day for two additional weeks.

All participants underwent brain imaging evaluation at the second week of each dosing regimen through resting state functional connectivity magnetic resonance imaging (rs-fcMRI) and proton magnetic resonance spectroscopy (1H-MRS).

They also were asked to respond to the Revised Fibromyalgia Impact Questionnaire (FIQR) to assess changes in overall symptoms, and the impact of fibromyalgia during treatment.

The collected data showed that treatment with NYX-2925 led to significant changes compared with placebo in imaging activity biomarkers in key pain-regulating brain regions. These changes were found to be associated with increased reductions in patient-reported sensitivity to pain following treatment with 20 mg NYX-2925.

Low-dose NYX-2925 also showed an ability to reduce nerve cells connectivity in brain areas known to be associated with the processing of centralized chronic pain.

Evaluation of fibromyalgia symptoms revealed that treatment with high dose NYX-2925 for two weeks could induce significant clinical improvements in average daily pain score, worst daily pain score, total FIQR score, and fatigue compared with placebo.

NYX-2925 was shown to be safe and well-tolerated, with no treatment discontinuations being reported during the trial due to therapy-related adverse events.

“The results from this study are very encouraging based on our previous demonstration of the relevance of these neural markers in patients with fibromyalgia,” said Steven Harte, PhD, associate research scientist and director of sensory science at Michigan’s Chronic Pain and Fatigue Research Center.

“We were able to objectively measure that NYX-2925 is affecting the apparent central manifestation of pain and other symptoms in these patients — a significant step forward in developing new therapeutic options for fibromyalgia,” Harte said.