Ipsen SAIpsen acquires Kartos Therapeutics for $450M upfront plus milestones, adding late-stage asset navtemadlin.

Ipsen has agreed to acquire Kartos Therapeutics in a deal that adds the late-stage rare blood cancer asset navtemadlin to its oncology pipeline. Under the definitive merger agreement, Ipsen will pay $450 million upfront at closing, with Kartos shareholders eligible for up to $1.3 billion in additional milestone payments including a significant regulatory approval milestone and sales-based milestones. Navtemadlin is an oral MDM2 inhibitor currently in a global Phase III registrational trial called POIESIS, which is designed to enroll more than 600 patients across over 250 sites as an add-on therapy to standard of care ruxolitinib in patients with intermediate and high-risk TP53 wild-type myelofibrosis who have a suboptimal response to ruxolitinib. Top-line data from the trial are expected in 2027, and the transaction is anticipated to close by the end of the third quarter of 2026, subject to customary closing conditions including the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act.
Ipsen SAIpsen acquires Kartos Therapeutics for $450M upfront plus milestones, adding late-stage asset navtemadlin.
Kartos Therapeutics is acquired by Ipsen for $450 million upfront plus up to $1.3 billion in milestones, providing a significant exit for shareholders.