Genmab makes $8bn acquisition to boost late-stage antibody therapy pipeline0 SHARESPosted: 29 September 2025 | Catherine Eckford (European Pharmaceutical Review) |The deal will support the biotech in its plans to advance bispecific antibody petosemtamab in multiple oncology indications. Genmab has agreed to acquire Netherlands-based biotech Merus for approximately $8 billion, giving it rights to late-stage breakthrough cancer therapy petosemtamab. Two phase III trials are currently evaluating petosemtamab in first- and second/third line head and neck cancer. Under the acquisition agreement, the Denmark-based biotech Genmab also aims to advance petosemtamab for potential expansion into earlier lines of therapy. “Our two companies have a rich history of innovation with multiple approvals in the field of multi-specific antibodies.