Arcus was founded in 2015 by Terry Rosen and Juan Jaen to discover and develop innovative cancer immunotherapies based on known but under-exploited biology.

Prior to starting Arcus, Terry and Juan founded Flexus Biosciences, which in February 2015 sold its preclinical-stage IDO inhibitor to Bristol-Myers Squibb for $800M upfront and $450M in milestones. The inhibition of IDO is now viewed as one of the most promising immuno-oncology mechanisms in late-stage development. We believe there is a significant opportunity to develop novel drugs that target other prevalent mechanisms of tumor-induced immuno-suppression or that act through the selective activation of effector immune mechanisms.

Arcus’s lead program targets the adenosine pathway, which has been shown to play a significant role in driving immuno-suppression in the tumor micro-environment.

Like IDO inhibitors, adenosine receptor antagonists and inhibitors of adenosine production are expected to be highly synergistic with other immuno-oncology mechanisms, as well as with chemotherapy. Because of the promise of the adenosine pathway, several adenosine receptor antagonists that were discovered years ago and initially developed for other indications have been repurposed for oncology. Using our expertise in medicinal chemistry and drug discovery, we have generated novel, small molecule dual antagonists of key adenosine receptors A2aR and A2bR. We believe that our lead molecule, AB928, will be the first clinical compound that was designed specifically for its immune-stimulating properties. AB928, like the IDO inhibitor we discovered at Flexus, has the potential to be best-in-class and we expect to advance this compound into clinical trials later this year. We have other product candidates in earlier stages of development that target the adenosine pathway, including a CD73 inhibitor (which blocks the generation of extracellular adenosine in tumors) that could be the first small-molecule inhibitor of CD73 to enter clinical trials.

We also have several small-molecule programs in earlier stages of discovery targeting other key pathways in immuno-oncology.

In addition to our small- molecule programs, we are advancing several antibody programs against other targets. We expect to initiate clinical trials in 2018 for AB154, our lead antibody product candidate which targets TIGIT. An important element of our strategy is the development of intra-portfolio combinations of our small- molecule and antibody product candidates, and we believe that many of these combinations will be the first to advance into clinical trials.

Arcus currently has approximately 75 employees with significant expertise in immunology, medicinal chemistry, biochemistry, enzymology, pharmacology and structural biology. We have also built in-house preclinical and early clinical development capabilities. Many of the members of our senior scientific team worked together for years at Tularik, Amgen and, most recently, Flexus.

We are based in Hayward, CA where we have over 72,000 square feet of laboratory and office space.