Merck is nearing a roughly $6bn acquisition of Terns Pharma, a US biotech developing treatments for chronic myeloid leukaemia (CML), a rare blood and bone marrow cancer. The deal represents Merck's latest aggressive move to replenish its oncology pipeline ahead of the 2028 patent expiry of its blockbuster drug Keytruda. Merck has already spent $10bn on Verona Pharma and $9.2bn on Cidara Therapeutics last year, positioning itself as the most active biotech acquirer amid an estimated $320bn in industry revenue losses from expiring patents through 2030. Investors have rewarded Merck, with its share price rising 38% since the Verona acquisition, giving it a market value of $287bn as of Tuesday. Terns currently trades at $5.3bn, meaning the deal would command a significant premium.

This acquisition would give Merck a stake in Terns' late-stage CML treatment, which could potentially displace Novartis' Scemblix, whose peak sales projections Merck has raised to $4bn.