Seattle Genetics conjugates with immuno-oncology upstart Unum in $645M deal

Just 8 months after gathering together a $12 million A round to get started with its own twist on adaptive T-cell technology, Cambridge, MA-based Unum Therapeutics has teamed up with Seattle Genetics in a $645 million immuno-oncology deal designed to marry some finely tuned antibody drug conjugate technology with the latest in cancer-fighting R&D.

In the deal, Seattle Genetics ($SGEN) will apply its extensive portfolio of tumor-specific antibodies to Unum's next-gen T-cell cause. And it's buying in to the deal, paying $25 million as an upfront and making a $5 million equity investment in Unum for the chance to position itself with an ally in this hot new cancer field. Another $615 million in milestones is also in play for up to three antibody-coupled T-cell receptor (ATCR) programs.

Unum will take the lead on preclinical and clinical activities through Phase I, then split the work with Seattle Genetics for the rest of the ride. The two companies will also co-commercialize any products that come out of the deal in the U.S., with Seattle Genetics taking the rights outside the U.S.

Unum and its team of Novartis vets emerged into the biotech spotlight last fall, promising to take a new approach on next-gen ATCR drugs. A group of pioneers like Juno ($JUNO), Kite ($KITE) and Novartis ($NVS) initially set out to create new CAR-T drugs by adding a chimeric antigen receptor to T cells to spur them on a search-and-destroy mission against tumor cells. But TCRs extend the list of targets to the inside of cancer cells, expanding their potential role. And Unum believes its particular approach to ATCRs has the chance of creating even better off-the-shelf therapies for both hematological malignancies as well as solid tumors, rather than the personalized treatments that will rely on adapting patients' cells.

That autologous-vs.-allogeneic approach to cells comes with major market implications. Adapting patient cells, an approach that has already triggered significant clinical data as well as worrying safety issues, would be significantly more complex than a universal therapy. But this new approach also has a long clinical journey ahead in order to prove itself relatively safe and effective.

Fidelity Biosciences and Atlas Venture led the A round for Unum, with some assistance from Sanofi-Genzyme BioVentures.

"Unum's strategy is to develop and commercialize a universal cellular immunotherapy that can be used in combination with a variety of antibodies to attack a wide range of hematological and solid tumors," said Charles Wilson, the CEO of Unum Therapeutics. "We believe that our unique approach has the potential to advance beyond the safety and efficacy limitations of current generation T-cell approaches."

- here's the release