Novimmune, TG ally to take CD47-CD19 bispecific into clinic

Novimmune has brought TG Therapeutics on board to help with the development of its CD47-CD19 bispecific antibody. TG will fund and run early-phase clinical trials of the treatment for hematologic B-cell malignancies, with Novimmune set to return to help out with the pivotal program.

Swiss biotech Novimmune has designed the bispecific to unlock the potential of CD47, a receptor that tumors express to evade immune attacks. CD47’s "don’t eat me" function makes it an interesting target, but its ubiquity in healthy tissues creates selectivity challenges. Novimmune’s workaround is to target both CD47 and CD19. The CD19 arm ensures selectivity for tumor cells, while the CD47 arm equips the bispecific to trigger phagocytosis and cell-mediated cytotoxicity to take out blood cancers.

Novimmune has spent the past few years validating the concept in preclinical tests, and at one point planned to take the drug into the clinic itself in 2017. That idea fell by the wayside, though. Now, TG will take responsibility for starting tests in humans next year.

TG is making an upfront payment to buy into the program and will bankroll its progress up to the end of phase 2. Along the way, TG will make milestone payments to Novimmune. The deal is currently structured so that Novimmune and TG will share post-phase 2 development and commercialization costs. But it features an option for TG to take full control in return for up to $185 million in milestones.

The involvement of TG sets the stage for combination therapies down the line. TG’s lead candidate ublituximab is aimed at CD20, a target thought to be complementary to CD47. Irving Weissman’s group at Stanford spotted the potential of the combination around the start of the decade, leading to a trial of an anti-CD47 antibody and Roche’s CD20 drug rituximab, and the creation of Forty Seven.

Forty Seven went on to hoover up VC cash and team up with Merck KGaA and Roche, before recently filing to add around $100 million to its coffers through an IPO. TG and Novimmune are betting the additional targeting feature of their bispecific will make it a better treatment for B-cell blood cancers than Forty Seven’s prospect, enabling them to come from behind. 

"TG-1801 has demonstrated encouraging preclinical anti-tumor activity both as a single agent and in combination with anti-CD20 monoclonal antibodies," TG CEO Michael Weiss said in a statement. "With the addition of TG-1801 to our pipeline, we now have three targeted immunotherapies in-house that can potentially be used together to create a novel non-chemo treatment option that uses the body’s immune system to fight B-cell cancers, including NHL and CLL."