Genmab Acquires Merus for $8 Billion, Bolstering Oncology Pipeline

Danish pharmaceutical company Genmab has announced its acquisition of Netherlands-based biotech firm Merus for $8 billion, marking a significant move in the oncology drug development landscape. The deal, which is expected to close in the first quarter of 2026, centers around Merus' promising bispecific antibody petosemtamab, which has shown potential as a best-in-class treatment for head and neck cancer.

Acquisition Details and Strategic Fit

Genmab will purchase all of Merus' common shares for $97 each, representing a 41% premium over Merus' closing price on the Friday before the announcement. The acquisition aligns with Genmab's long-term strategy to shift towards a wholly owned model and accelerate its evolution into a global biotechnology leader.

Jan van de Winkel, 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: A Potential Blockbuster

The centerpiece of the acquisition is petosemtamab, Merus' bispecific antibody targeting EGFR and LGR5. In May, the drug demonstrated impressive results in a Phase II trial for head and neck squamous cell carcinoma:

• 79% overall survival rate at 12 months when used in combination with Merck's Keytruda
• 63% overall response rate
• 9-month median progression-free survival

These results have led analysts to describe petosemtamab as having a "best-in-disease profile" for head and neck cancer, with the potential to become the standard of care when combined with Keytruda.

Genmab has high expectations for petosemtamab, projecting:

• Potential market launch in 2027, pending successful completion of ongoing Phase III trials
• $1 billion in annual sales by 2029
• Multi-billion-dollar annual revenue potential thereafter

Impact on Genmab's Pipeline and Industry Trends

The acquisition of Merus significantly enhances Genmab's late-stage oncology pipeline. With the addition of petosemtamab, Genmab now has four wholly owned programs that could potentially bring new drugs to market by 2027.

This deal, along with recent acquisitions such as Pfizer's $4.9 billion Metsera takeover, suggests a potential uptick in M&A activity within the biopharma sector. BMO Capital Markets analysts noted, "We are encouraged by news of M&A discussions following lagging M&A activity over the last few years," adding that these deals "could start to spur broader M&A in the sector."