Genmab joins with Bolt to develop bispecific immune stimulators 

Genmab
Genmab is paying Bolt $10 million upfront and making a $15 million equity investment. (Genmab)

Genmab and Bolt Biotherapeutics have teamed up to develop bispecific immune-stimulating antibody conjugates (ISACs). The collaboration brings together Genmab’s bispecific capabilities with Bolt’s innate immune stimulant platform to create a new type of immuno-oncology drug.

Bolt raised a $230 million IPO early this year on the strength of a platform and pipeline designed to overcome the limitations of immunostimulatory adjuvants such as toll-like receptor (TLR) 7/8 agonists. Recognizing that TLR agonists cause toxicities associated with widespread immune activation after being given systemically, Bolt conjugated its immunostimulatory adjuvants to tumor-targeting antibodies to trigger a localized response. 

The idea has caught the attention of Genmab, the biotech behind Johnson & Johnson’s blockbuster anti-CD38 antibody Darzalex. Genmab is contributing its own antibodies and bispecific antibody engineering technologies to the collaboration, positioning the partners to develop a twist on the ISAC concept.   

“Bispecifics enable targeting tumors with increased specificity and/or additional or enhanced functionality, and in both cases that could be further enhanced with an innate immune stimulant to create a bispecific ISAC,” David Dornan, Ph.D., chief scientific officer at Bolt, said. 

Genmab is paying Bolt $10 million upfront and making a $15 million equity investment in the biotech to enter into the deal as well as agreeing to fully fund preclinical and early clinical development of all candidates. In return, Genmab has secured the option to develop and commercialize up to three candidates. Bolt can participate in the development and commercialization of one asset.

Bigger sums await Bolt as the three candidates advance. Bolt is in line to receive up to $285 million in milestones for each candidate Genmab takes forward on its own. If Bolt co-develops one of the candidates, the partners will split development costs down the middle and will each be solely responsible for funding commercialization in their respective territories.  

The agreement is the latest example of Genmab’s interest in partnering to access technologies that may complement its antibody expertise. In 2019, for example, Genmab partnered with CureVac to work on mRNA-based antibody products. That deal came around 18 months after Genmab struck a deal to access Immatics Biotechnologies’ T-cell receptor capabilities.