** Drug developer Tenaya Therapeutics' TNYA.O shares slide 12.5% to $1.19 in extended trading

** TNYA unveils public offering of common stock and warrants; size not disclosed

** Leerink Partners and Piper Sandler are joint bookrunning managers for offering

** Separately, TNYA announces data from early trial for experimental gene therapy in rare heart condition

** TNYA has 166.5 million outstanding shares for $233 million market cap, per LSEG data

** All eight brokerages covering the stock rate it "buy" or higher; median PT $5 - data compiled by LSEG

** As of last close, TNYA stock down 4.9% YTD

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com;))