Aptinyx is temporarily pausing a phase 2b study of its post-traumatic stress disorder (PTSD) drug in order to conserve cash, the company disclosed Tuesday in a regulatory filing.
The biotech has postponed initiating the 150-mg arm of its phase 2b trial examining NYX-783 in patients with PTSD. The second arm of that trial, testing a 50-mg dose, will continue and “will be supported by clinical study sites originally slated for the 150 mg study.” In a statement, CEO Andy Kidd said the decision was made to save funds.
“Pausing the high dose PTSD study allows Aptinyx to concentrate our resources on the dose that showed promising activity in the previous Phase 2 PTSD study (the 50 mg dose)," Kidd said. "This allows Aptinyx to manage our existing balance sheet to deliver on planned readouts in fibromyalgia, cognition and PTSD. This means that, irrespective of the availability of additional capital, our current balance sheet will enable phase 2 readouts across each indication in our pipeline.”
The plan had originally been for the 150-mg arm to commence after the 50-mg arm was initiated, which began in December 2021. Evidently, those plans fell through. Each arm of the phase 2 trial was designed to be randomized, double-blinded and parallel, assessing 10 weeks of once-daily treatment in approximately 300 patients.
The phase 2b trial followed results released in October 2020 from an exploratory phase 2 trial showing that both a 10-mg and a 50-mg dose of the drug improved PTSD symptoms in patients. Aptinyx received fast-track designation from the FDA in 2017. In its latest annual report, the company said it may pursue other neuropsychiatric indications for the drug, including “substance use disorders in which the enhancement of extinction learning processes observed with NYX-783 may offer therapeutic benefits.”
The pause marks the continuation of a difficult April after the company reported two weeks ago that its pain reliever for patients with painful diabetic peripheral neuropathy, NYX-2925, failed to alleviate pain in a phase 2b study. The results were a death blow for further development of the drug in that indication. The company will now turn its sights toward testing the med to treat fibromyalgia in a phase 2b study. Early data from that trial are slated to read out in the early to mid- third quarter.
Aptinyx has only three drugs in its pipeline. In addition to NYX-2925 and 783, the company is testing NYX-458 in a phase 2 trial to treat cognitive impairment associated with Parkinson’s disease and dementia associated with Lewy bodies.
Editor's note: This story was updated at 6:20pm ET to include a statement from Aptinyx CEO Andy Kidd.