** Shares of drug developer Poseida Therapeutics PSTX.O
more than triple to $9.18 premarket
** Switzerland's Roche Holding ROG.S to buy PSTX in cash
deal worth up to $1.5 bln, co says
** ROG will pay $9 per share in cash plus up to $4 extra
based on future milestones, PSTX says
** Deal builds on 2022 Roche-Poseida partnership on CAR-T
therapies for blood cancers
** Deal is expected to close in Q1 2025
** As of last close, PSTX down ~15% YTD
(Reporting by Kamal Choudhury)
((Kamal.Choudhury@thomsonreuters.com;))