** Shares of Neuren Pharmaceuticals NEU.AX plunges as much as 10.7% to A$13.06

** Biotech says FDA will only provide written responses for NNZ-2591 drug development meetings, not face-to-face discussions as requested

** Drug targets hypoxic ischemic encephalopathy and Pitt Hopkins syndrome

** Stock fell 10% on Feb 3 on setback for Rett treatment drug application from European regulator, trading halt on Feb 4 pending FDA update

(Reporting by Nichiket Sunil in Bengaluru)

((Nichiket.Sunil@thomsonreuters.com))