** Goldman Sachs resumes coverage on drug developer Altimmune ALT.O with "sell" rating and $1 PT

** Shares of ALT fall 11.4% to $4.22

** PT implies a ~79% downside to the stock's last close

** ALT’s main drug, pemvidutide, is being developed to treat obesity and certain liver diseases

** Brokerage says while the company is focusing on liver-related conditions, studies so far show pemvidutide works, but it isn’t significantly better than similar drugs from other companies

** Brokerage believes the obesity and liver disease treatment market is crowded with many competing drugs

** Because the drug isn't very different from others and competition is strong, the brokerage sees it as difficult for ALT to successfully bring pemvidutide to market

** As of last close, ALT stock down 34.3% YTD

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com))