** Shares of healthcare firm Organon OGN.N rise 4.65% to $7.88 premarket
** Co and Shanghai Henlius Biotech say US FDA approves their breast cancer drug Poherdy
** The two companies' Poherdy first biosimilar to rival Roche's ROG.S Perjeta for HER2-positive breast cancer - OGN
** Co says drug to be used with other therapies for advanced or early-stage breast cancer; Organon to market in U.S - OGN
** Poherdy carries warnings for heart issues and birth defects; doctors advised to monitor patients, co says
** Up to last close, stock down ~50% YTD
(Reporting by Sahil Pandey in Bengaluru)
((Sahil.Pandey@thomsonreuters.com))