** Shares of drug developer Unicycive Therapeutics UNCY.O fall 27% to 65 cents premarket

** UNCY says U.S. FDA has identified manufacturing issues with third-party vendor of its kidney disease drug, oxylanthanum carbonate

** Co says FDA cannot discuss drug labeling with UNCY until these issues are resolved

** Adds it is working to resolve FDA's concerns and is confident in drug's potential to treat hyperphosphatemia, which is condition where there are high phosphate levels in patients on dialysis

** Despite issues, final FDA decision is expected by original action date of June 28

** As of last close, stock up 13.3% YTD

(Reporting by Kamal Choudhury in Bengaluru)

((Kamal.Choudhury@thomsonreuters.com;))