Novo Nordisk bids $9bn for obesity drug maker Metsera in challenge to Pfizer

US biotech viewed as lucrative target partly because of its promising pipeline of weight-loss drugs

Novo Nordisk has launched a surprise $9bn (6.9bn) offer for the US obesity-focused biotech firm Metsera that could gazump an existing bid from Pfizer as the pharmaceutical giants fight for dominance in the weight-loss market.

The bid comes weeks after Metsera agreed to a $7.3bn takeover from the US group Pfizer. Denmark's Novo Nordisk, which owns the weight-loss drugs Ozempic and Wegovy, lost out in a competitive auction processin September.