** Metsera MTSR.O shares plunge 15.7% to $70.12 premarket after a fierce bidding war for the drugmaker ended late on Friday
** MTSR accepts Pfizer's PFE.N $10 bln acquisition bid, and co-bidder Novo Nordisk NOVOb.CO said it would exit the race
** PFE agrees to pay $86.25/share in cash, a 3.69% upside to Metsera's Friday close
** Metsera accepted Pfizer's sweetened offer citing "unacceptably high legal and regulatory risks" in Novo's bid
** Bernstein says Pfizer's $10 billion valuation is optimistic, requiring $11 billion in revenue by 2040
** MTSR shares had surged nearly 60% last week amid bidding war
** MTSR shares have climbed more than threefold since their January IPO, while PFE stock is down 7.82% YTD, as of last close
(Reporting by Tharuniyaa Lakshmi and Pranav Kashyap in Bengaluru)
((tharuniyaa@thomsonreuters.com))