Pharma BD Deal Intelligence

Ipsen S.A. / Kartos Therapeutics, Inc.

2026 · Acquisition/Merger · $1.8B · Pending

CALLED IT — OFF BY 5

Late-stage myelofibrosis asset deepening Ipsen hemato-oncology

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On June 29, 2026, Ipsen entered a definitive merger agreement to acquire US hemato-oncology biotech Kartos Therapeutics for $450 million upfront at closing plus up to $1.3 billion in milestones (regulatory-approval and sales-based), for total potential consideration of up to ~$1.75 billion. The deal adds navtemadlin (KRT-232), an investigational oral MDM2 inhibitor designed to restore p53 tumor-suppressor function, being evaluated as add-on to ruxolitinib in myelofibrosis patients with suboptimal response (Phase 3 POIESIS; top-line data expected 2027). The transaction is expected to close by end of Q3 2026 and to be accretive to Ipsen core operating income from 2029.

Key facts

Related deals — scored

DealYearValueOutcome
Ipsen S.A. / Kartos Therapeutics, Inc. (this deal)2026$1.8B68
Ipsen S.A. / Exelixis Inc.2016$855M80
Ipsen S.A. / Memo Therapeutics AG2026$797M66
Ipsen S.A. / Clementia Pharmaceuticals Inc.2019$1.3B
Ipsen S.A. / Marengo Therapeutics, Inc.2024$1.2B
Ipsen S.A. / GENFIT2021$543M
Ipsen S.A. / Simcere Zaiming Pharmaceutical Co., Ltd.2025$1.1B

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