Ipsen bets on navtemadlin to extend Jakafi-era in myelofibrosis via Kartos deal
Ipsen agreed to acquire Kartos Therapeutics for $450 million upfront and up to $1.3 billion in milestones to obtain navtemadlin, an oral MDM2 inhibitor designed to reactivate p53 in patients with intermediate/high-risk TP53 myelofibrosis who have suboptimal responses to Jakafi; Kartos' phase 1b/2 data showed meaningful spleen volume and symptom improvements when added to Jakafi, and a phase 3 trial enrolling 600+ patients is ongoing with topline readout expected next year and a potential U.S. launch around 2028 if successful.