Genmab to Acquire Merus: Expanding Pipeline and Transitioning to Wholly Owned Model

09/29/2025 – 01:14 AM

Company Announcement

• Genmab to acquire Merus for USD 97.00 per share in an all-cash transaction representing a transaction value of approximately USD 8.0 billion
• Proposed acquisition adds petosemtamab, a late-stage asset with two Breakthrough Therapy Designations, to Genmab’s portfolio
• Transaction anticipated to be accretive to EBITDA by end of 2029
• Genmab to host a conference call today at 1:00 PM CEST / 12:00 PM BST / 7:00 AM EDT

COPENHAGEN, Denmark & UTRECHT, Netherlands–(BUSINESS WIRE)–Genmab A/S (Nasdaq: GMAB) and Merus N.V. (Nasdaq: MRUS) announced today a definitive agreement under which Genmab will acquire all outstanding shares of Merus, a clinical-stage biotechnology company, for USD 97.00 per share in cash. The deal, valued at approximately USD 8.0 billion, aims to bolster Genmab’s pipeline with the addition of petosemtamab, a promising late-stage asset currently in Phase 3 development and holding two Breakthrough Therapy Designations.

Both companies’ Boards of Directors have unanimously approved the transaction, signaling strong confidence in the strategic rationale. A Genmab subsidiary will initiate a tender offer for all of Merus’ common shares, with the acquisition expected to finalize by early in the first quarter of 2026, subject to customary closing conditions.

Genmab anticipates the acquisition will accelerate its transition towards a fully-owned business model, broadening and diversifying its revenue streams. By incorporating petosemtamab, Genmab enhances its late-stage pipeline, aligning with its strategic focus on antibody therapy development and commercialization, particularly in oncology. Upon completion, Genmab is projected to have four in-house programs poised to launch multiple new drugs by 2027.

Jan van de Winkel, Ph.D., President and CEO of Genmab, stated, “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 commercialization, we are confident that we will be able to unlock the promise of petosemtamab.”

Bill Lundberg, M.D., President and CEO of Merus, added, “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.”

Petosemtamab, an EGFRxLGR5 bispecific antibody, is positioned as a potential leader in head and neck cancer treatment. The FDA has granted it Breakthrough Therapy Designations for first- and second-line plus head and neck cancer indications. Impressive Phase 2 data, presented at the American Society for Clinical Oncology (ASCO) 2025 Annual Meeting, showed superior overall response rate and median progression-free survival compared to standard treatments.

Currently, Merus is conducting two Phase 3 trials targeting first- and second/third-line head and neck cancer, with interim topline data expected in 2026. Leveraging Genmab’s expertise in late-stage development and commercial capabilities, the company anticipates a potential initial launch of petosemtamab in 2027, contingent on clinical results and regulatory approvals. Genmab also aims to expedite and broaden petosemtamab’s development, potentially expanding into earlier lines of therapy. The company forecasts EBITDA accretion and annual sales potential of at least $1 billion by 2029, with significant revenue growth expected thereafter.

Transaction Details and Financing

Under the agreement, Genmab’s subsidiary will initiate a tender offer for all outstanding Merus common shares. Post-tender offer, Genmab will execute a series of transactions ultimately leading to full ownership of Merus. The USD 97.00 per share offer represents a premium of approximately 41% over Merus’ closing stock price on September 26, 2025, and roughly 44% over its 30-day volume-weighted average price.

The acquisition is not subject to financing conditions. Genmab intends to finance the deal through a combination of existing cash reserves and approximately $5.5 billion in non-convertible debt financing, with Morgan Stanley Senior Funding, Inc. providing a funding commitment.

This financing includes a substantial portion of prepayable debt, aligning with Genmab’s commitment to deleveraging, with a target of gross leverage guidance for the full year 2025, last issued on August 7, 2025. Genmab will release its financial outlook for 2026 in conjunction with its full-year 2025 earnings report in February 2026.

PJT Partners and Morgan Stanley & Co. International plc are acting as joint financial advisors to Genmab, with A&O Shearman and Kromann Reumert serving as legal advisors. Jefferies LLC is serving as financial advisor to Merus, with Latham & Watkins and NautaDutilh as legal advisors.

About Genmab

Genmab is an international biotechnology company with a core purpose of guiding its unstoppable team to strive toward improving the lives of patients with innovative and differentiated antibody therapeutics. For more than 25 years, its passionate, innovative and collaborative team has invented next-generation antibody technology platforms and leveraged translational, quantitative and data sciences, resulting in a proprietary pipeline including bispecific T-cell engagers, antibody-drug conjugates, next-generation immune checkpoint modulators and effector function-enhanced antibodies. By 2030, Genmab’s vision is to transform the lives of people with cancer and other serious diseases with knock-your-socks-off (KYSO) antibody medicines^®.

Established in 1999, Genmab is headquartered in Copenhagen, Denmark, with international presence across North America, Europe and Asia Pacific.

About Merus

Merus is an oncology company developing innovative full-length human bispecific and trispecific antibody therapeutics, referred to as Multiclonics^®. Multiclonics^® are manufactured using industry standard processes and have been observed in preclinical and clinical studies to have several of the same features of conventional human monoclonal antibodies, such as long half-life and low immunogenicity.

Forward-Looking Statements: This announcement contains forward-looking statements that involve risks and uncertainties. Actual results could differ materially due to various factors, including regulatory approvals, clinical trial outcomes, market conditions, and integration challenges. Investors are urged to review Genmab’s and Merus’ filings with the SEC for a complete discussion of these risks.