Pfizer is doubling down on obesity treatments by spending $4.9 billion on the development-stage drugmaker Metsera. The COVID-19 vaccine and treatment maker said early Monday that it will pay$47.50 per share in cash for each Metsera share. That represents a premium of more than 42% to Metsera’s closing price Friday. Pfizer also could pay an additional $22.50 per share depending on how Metsera’s product pipeline develops. Metsera has no products on the market, but its pipeline includes four programs in ...