French biopharmaceutical company Ipsen (Euronext Paris:IPN) (ADR:IPSEY) announced on Friday that it has completed the acquisition of Kartos Therapeutics, adding the clinical-stage biopharmaceutical company's late-stage MDM2 inhibitor navtemadlin to its oncology pipeline.

Navtemadlin is an investigational oral MDM2 inhibitor being developed as an add-on to ruxolitinib for patients with myelofibrosis who have a suboptimal response to treatment. The Phase III POIESIS study is evaluating whether navtemadlin can improve clinical outcomes compared with ruxolitinib alone.

Early clinical data indicate navtemadlin may improve responses among patients with intermediate- and high-risk TP53wt myelofibrosis and potentially provide disease-modifying benefits.

Myelofibrosis is a myeloproliferative neoplasm associated with bone marrow fibrosis, splenomegaly, bone marrow failure and a high symptom burden, with a risk of progression to acute myeloid leukemia. Ruxolitinib, a JAK inhibitor, is the first-line standard of care, but a significant proportion of patients have a suboptimal initial response and an estimated 50%-75% discontinue treatment within three years.

This acquisition strengthens Ipsen's late-stage oncology pipeline and adds a Phase III programme targeting an area with significant unmet medical need.