** Shares of drug developer Aptinyx Inc APTX.O fall 54.31%
to $0.27 premarket; top pct loser across U.S. exchanges
** Company said late on Monday its drug NYX-458 did not
demonstrate clinically meaningful improvements over placebo in a
mid-stage study
** The drug was being studied in patients with cognitive
impairment associated with Parkinson's disease and dementia with
Lewy bodies
** Company said the results do not support further
development of NYX-458
** APTX will undertake cost-saving measures, including
termination of its ongoing mid-stage study of NYX-783 for
post-traumatic stress disorder
** Last year, company's experimental drug NYX-2925 failed to
meet main goals in two mid-stage trials testing the drug for
nerve pain and fibromyalgia, a disorder that causes muscular
pain
** Stock lost ~89% in 2022
(Reporting by Sriparna Roy)
((Sriparna.Roy@thomsonreuters.com))