Danish biotech firm Genmab to acquire Dutch oncology company Merus for €6.8B

Genmab to acquire Utrecht-based Merus in an all-cash deal expected to close in early 2026, adding Merus’ cancer therapies to its pipeline.

Copenhagen’s biotechnology company Genmab and Utrecht-based Merus, an oncology company, announced that they have signed an agreement under which Genmab will acquire all outstanding shares of Merus.

This acquisition involves Merus’ therapy asset, petosemtamab, which is in Phase 3 development. Genmab will pay $97 (€82.55) per share in an all-cash deal, representing a total transaction value of approximately $8B (nearly €6.8B).

The Boards of Directors of both companies have approved the transaction. A wholly owned subsidiary of Genmab will initiate a tender offer for all Merus common shares. The tender offer is expected to close in the first quarter of 2026.

Aim of the acquisition

Merus is a company that develops cancer treatments. It is working on Multiclonics, which are antibodies designed to target more than one part of a cancer cell. These therapies are made using standard laboratory and manufacturing methods. In early tests and studies with people, Multiclonics show similar behaviour to regular human antibodies, including staying in the body for a long time and causing minimal immune reactions.

The acquisition of Merus is intended to shift Genmab to a wholly owned model, expand and diversify the company’s revenue, support growth over the next decade, and advance Genmab’s development in biotechnology.

A key component of the acquisition is Merus’ lead asset, petosemtamab, an EGFRxLGR5 bispecific antibody for head and neck cancer. This addition strengthens Genmab’s late-stage pipeline and aligns with its focus on antibody therapy development and commercialisation in oncology. 

Following the transaction, Genmab will have four proprietary programs expected to enable multiple new drug launches by 2027.

Petosemtamab has received two FDA Breakthrough Therapy Designations for first- and second-line head and neck cancer indications. Phase 2 data presented at the American Society for Clinical Oncology 2025 Annual Meeting demonstrated “compelling” overall response rates and median progression-free survival above the current standard of care.

Merus is currently conducting two Phase 3 trials in first- and second/third-line head and neck cancer, with topline interim results expected in 2026. Based on Genmab’s expertise in late-stage development and commercial execution, the company expects the initial launch of petosemtamab in 2027, subject to clinical results and regulatory approvals. 

Genmab plans to expand development into earlier lines of therapy, with petosemtamab projected to contribute to EBITDA and achieve at least $1B in annual sales by 2029, with potential for higher revenue thereafter.

Jan van de Winkel, Ph.D., President and CEO of Genmab, says, “The proposed acquisition of Merus clearly aligns with our long-term strategy. It has the potential to significantly accelerate our evolution into a global biotechnology leader by providing durable growth for the company well into the next decade.”

“Petosemtamab has the potential to be a transformational therapy for patients living with head and neck cancer. With our proven track record of success, both in clinical development and in commercialisation, we are confident that we will be able to unlock the promise of petosemtamab.”

Bill Lundberg, M.D., President, CEO of Merus, adds, “We are excited for the opportunity to join Genmab, a leader in antibody therapeutics, to further develop and bring petosemtamab to patients. Our two companies have a rich history of innovation with multiple approvals in the field of multispecific antibodies.”

“We believe Genmab has the right vision and experience to advance petosemtamab in recurrent/metastatic head and neck cancer and beyond. I’m immensely proud of the Merus team who have pioneered our foundational platform technologies to make better medicines and who have demonstrated – with an approved product and a product candidate, petosemtamab, in registrational studies – an ability to deliver on our promise to close in on cancer.”

Transaction details

Genmab’s wholly owned subsidiary will start a tender offer for all outstanding common shares of Merus. After the tender offer closes, Merus and Genmab will carry out a series of transactions resulting in Genmab owning 100 per cent of Merus’ common shares or a successor entity.

Shareholders who do not participate in the tender offer will either receive the same consideration as shares tendered or a price determined by a Dutch court.

The tender offer requires at least 80 per cent of Merus’ shares to be tendered, which Genmab may reduce to 75 per cent if other closing conditions are met, including shareholder approval of governance and back-end transactions and completion of works council consultations.

The purchase price is $97 per share. The transaction will be funded with cash on hand and approximately $5.5B in non-convertible debt financing, with a commitment obtained from Morgan Stanley Senior Funding, Inc. 

The financing includes prepayable debt, and Genmab aims to reduce gross leverage to below 3x within two years of closing. The deal does not affect Genmab’s financial guidance for 2025. The company will provide its 2026 financial outlook in February 2026.

Brief about Genmab

Genmab is a biotechnology company focused on developing antibody therapeutics for patients. Since 1999, the company has created antibody technology platforms and applied translational, quantitative, and data sciences, resulting in a pipeline that includes bispecific T-cell engagers, antibody-drug conjugates, next-generation immune checkpoint modulators, and effector function-enhanced antibodies. 

Genmab is headquartered in Copenhagen, Denmark, and has operations in North America, Europe, and the Asia Pacific.