French drugmaker Ipsen has agreed to acquire U.S.-based Kartos Therapeutics for $450 million upfront, with the deal potentially rising to $1.75 billion if regulatory and sales milestones are met. The acquisition gives Ipsen access to navtemadlin, a late-stage blood cancer treatment in development for myelofibrosis.
Under the terms of the agreement, Kartos shareholders could receive up to $1.3 billion in additional milestone payments. Ipsen said the transaction strengthens its oncology pipeline and is expected to close by the end of the third quarter of 2026, subject to regulatory approvals.
