June 29 (Reuters) - Ipsen IPN.PA will buy U.S.-based Kartos Therapeutics for $450 million to expand its oncology pipeline with a late-stage blood cancer treatment, the French biotech company said on Monday.

• The deal gives Ipsen navtemadlin, an investigational oral therapy being evaluated in a Phase III trial for patients with myelofibrosis, a rare blood cancer.

• Kartos shareholders will be eligible for up to $1.3 billion in additional milestone payments tied to regulatory and sales targets.

• Initial trial data is expected in 2027, potentially paving the way for the therapy to be launched as early as 2028.

• Ipsen says the acquisition will boost core operating income from 2029.

• The deal is expected to close by the end of the third quarter of this year, subject to antitrust clearance.