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Ipsen to acquire Kartos Therapeutics, expanding hemato-oncology late-stage pipeline
Ipsen to acquire Kartos Therapeutics, expanding hemato-oncology late-stage
About this update from Ipsen Sa
Acquisition adds navtemadlin, a late-stage rare blood cancer asset in Phase III. This hemato-oncology program in myelofibrosis expands Ipsen’s growing Oncology portfolioNavtemadlin, an oral MDM2 inhibitor, has the potential, through disease modifying activity, to transform suboptimal responses to standard of care ruxolitinib into clinically meaningful responses in patients with myelofibrosis Top-line data from the ongoing Phase III registrational trial POIESIS is expected in 2027PARIS, FRANCE AND REDWOOD CITY, U.S., 29 JUNE 2026 - Ipsen (Euronext: IPN; ADR: IPSEY) and Kartos Therapeutics, announced today they have entered into a definitive merger agreement under which Ipsen has agreed to acquire Kartos Therapeutics. The acquisition adds navtemadlin, an investigational MDM2 inhibitor designed to restore the natural tumor-suppressing function of p53, a critical tumor-suppressor in myelofibrosis. Data show strong therapeutic potential of navtemadlin for intermediate and high-risk TP53 wild-type (wt) myelofibrosis as an add-on treatment for patients with a suboptimal response to standard of care ruxolitinib. “This acquisition further strengthens our late-stage oncology pipeline and reflects our continued focus on bringing transformational treatments to people living with cancer,” said David Loew, CEO, Ipsen. “We are excited by the potential of navtemadlin to define a new treatment paradigm for patients with myelofibrosis who have a suboptimal response to current standard of care, addressing a critical care gap and offering the potential for a new therapeutic option as early as 2028.” Current standard of care ruxolitinib improves splenomegaly and myelofibrosis-related symptoms. However, a significant proportion of patients experience a suboptimal response to ruxolitinib, resulting in treatment discontinuation. Patient outcomes after ruxolitinib discontinuation are dismal, with a median overall survival of approximately 1-2 years. Navtemadlin is currently being evaluated in the global Phase III trial POIESIS designed to enroll >600 patients across >250 sites, as an add-on therapy to standard of care ruxolitinib in patients with intermediate and high-risk TP53wt myelofibrosis who have a suboptimal response to ruxolitinib. The trial builds on earlier clinical evidence, including a Phase Ib/II trial (KRT-232-109) in which add-on navtemadlin demonstrated clin...