** Shares of PTC Therapeutics PTCT.O fall 1.3% to $45.43 in morning trade

** Company, late on Tuesday, said it has discontinued development of its experimental drug to treat amyotrophic lateral sclerosis (ALS)

** The drug, utreloxastat, failed to slow disease progression, the main goal, in a mid-stage trial - PTCT

** "While this outcome is unfortunate, expectations were low given that drug development in ALS has been difficult and supporting evidence for utreloxastat in ALS was limited" - TD Cowen analysts

** ALS is a rare neurological disease that can break down nerve cells, in the brain and spinal cord, responsible for muscle movements

** Including session moves, stock up about 64% YTD

(Reporting by Mariam Sunny in Bengaluru)

((Mariam.ESunny@thomsonreuters.com;))