Synaffix, MacroGenics crack open ADC pact, tacking on $2.2B, 4 more programs

Just over a year ago, Synaffix and MacroGenics unveiled their antibody drug-conjugate (ADC) collaboration worth up to $586 million for three programs. Now, with interest in the modality ablaze, the two are widening the scope of the deal.

The expanded agreement will tack on up to four additional programs, increasing the potential deal value by $2.2 billion, according to a release Tuesday. It means MacroGenics now has the option to pursue up to seven ADC programs.

The cohesiveness of the deal centers on the two companies' compatibility; antibody-focused MacroGenics will be able to combine its DART platform for creating recombinant molecules designed to bind to two or more targets with Synaffix’s ability to replace the antibody glycan with a therapeutic payload.

Synaffix can now point to 13 companies that have publicly disclosed a total of 20 ADC candidates built with the company's tech, five of which are already in the clinic, according to Vice President of Business Development Anthony DeBoer. Just this year, the company announced a similar collab with Amgen worth up to $2 billion and another $150 million deal with Hummingbird Bio focused on a single program. As for the progress of its existing MacroGenics agreement, first signed in February 2022, Synaffix reports having two undisclosed candidates in the preclinical stage. 

The fervor around ADCs centers on the duality of the modality. The treatments come equipped with drug payloads attached to antibodies, intended to stymie tumor cells at the source while reinvigorating the immune system to fight the disease. The idea is that this technology can maximize cancer-fighting therapies while limiting toxic side effects spurred by off-target impact. 

Pfizer's announcement Monday that it had bought cancer behemoth Seagen for $43 billion, in large part to capitalize on the company’s ADC prowess, served as another reminder of the attention the modality is getting. 

The ongoing work between MacroGenics and Synaffix comes as the former is progressing five clinical candidates, led by vobramitamab duocarmazine, MacroGenics' wholly owned ADC. The asset is currently in a phase 2 trial to treat prostate cancer as well as a phase 1 trial to treat other solid tumors in combination with another of MacroGenics’ bispecific antibodies.