Key facts
- Ipsen will acquire U.S.-based Kartos Therapeutics for $450 million.
- The deal includes navtemadlin, an investigational oral therapy for myelofibrosis.
- Kartos shareholders could receive up to $1.3 billion in additional milestone payments.
- Ipsen anticipates the acquisition will enhance core operating income starting in 2029.
- The transaction is subject to antitrust clearance and expected to close by the end of Q3 2026.
French biopharmaceutical company Ipsen has entered into a definitive agreement to acquire U.S.-based Kartos Therapeutics for an initial cash payment of $450 million. The total transaction value could reach $1.75 billion if certain regulatory and commercial milestones are achieved.
This acquisition brings navtemadlin, an investigational oral MDM2 inhibitor, into Ipsen's oncology pipeline. Navtemadlin is currently being evaluated in a Phase III trial for patients with myelofibrosis, a rare blood cancer, particularly those with a suboptimal response to the standard treatment, ruxolitinib.
Ipsen CEO David Loew stated that the acquisition aligns with the company's focus on developing transformational treatments for cancer patients and could establish a new treatment paradigm for myelofibrosis as early as 2028. Data from earlier trials suggest navtemadlin has the potential to modify disease progression and improve symptoms in patients who do not fully respond to current therapies.
The deal is expected to close by the end of the third quarter of 2026, subject to customary closing conditions, including antitrust clearance. Ipsen anticipates the acquisition will contribute positively to its core operating income starting in 2029.