** Shares of Neuren Pharmaceuticals NEU.AX rise 11% to A$13.92, their highest since June 13

** Stock is the top gainer on the benchmark index .AXJO

** Stock on track for best day since April 14 if gains hold

** Co receives patent application approval from U.S. regulator for the use of its NNZ-2591 drug to treat Pitt Hopkins syndrome, a neurodevelopmental condition

** Says patent's expiry date will be in April 2040

** Including day's moves, stock up 11.7% YTD

(Reporting by Jasmeen Ara Shaikh in Bengaluru)

((JasmeenAraIslam.Shaikh@thomsonreuters.com;))