** Drug developer NKGen Biotech's shares NKGN.O surge 26% to 47 cents

** Company says U.S. FDA has granted "fast track" designation for its experimental drug, troculeucel, for the treatment of moderate Alzheimer's disease, a neurodegenerative disorder that causes cognitive impairment

** The FDA's "fast track" program is designed to facilitate the development and expedite review of drug candidates that aim to treat serious conditions and fulfill an unmet medical need

** NKGN is also developing the drug as a treatment for other neurodegenerative disorders and a broad range of cancers

** Stock fell ~71% in the last 12 months

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com))