Ipsen to Acquire Kartos Therapeutics for Up to $1.75 Billion

By EC Assets · Published 29 June 2026

Ipsen has agreed to acquire Kartos Therapeutics for an upfront payment of $450 million. The deal includes potential milestone payments of up to $1.3 billion, bringing the total value to $1.75 billion. This acquisition expands Ipsen's hematology pipeline. The agreement was announced on Monday, June 28, 2026. Kartos Therapeutics is a clinical-stage biopharmaceutical company. It develops navtemadlin, an MDM2 inhibitor. Navtemadlin is designed for myelofibrosis, specifically for ruxolitinib non-responders. Data from Phase III trials for navtemadlin are anticipated in 2027. The acquisition adds a phase III asset to Ipsen's portfolio. Ipsen expands its hemato-oncology late-stage portfolio with this agreement. Navtemadlin is described as a potential best-in-class MDM2 inhibitor. This article is intended for informational purposes only. It does not constitute investment advice.