Upstart Kezar wrangles $23M to pick up where Onyx left off

Kezar CSO Christopher Kirk

South San Francisco startup Kezar Life Sciences is looking to follow through on some promising programs discovered at Onyx Pharmaceuticals, raising $23 million and securing Amgen's ($AMGN) blessing as it targets autoimmune disease.

The biotech's lead asset is designed to treat diseases of the immune system by modulating the body's natural disposal of proteins. Like Onyx's blockbuster cancer treatment Kyprolis, Kezar's candidate targets the proteasome, used by the body to degrade broken or unneeded proteins. The company is particularly focused on the immunoproteasome, which helps regulate how T cells respond to threats, and Kezar believes its approach could create a novel way to treat autoimmune diseases.

Amgen, which acquired Onyx for about $10 billion in 2013, has licensed the immunoproteasome technology to Kezar, and the biotech has put together a $23 million A round to advance its development. Amgen is also taking a minority equity interest in the company.

Now Kezar is blueprinting Phase Ia and Ib trials for its lead asset, building off of some positive results in animal models. The company plans to nail down the safety profile of its top program before moving into efficacy studies, touting its lead drug's potential in rheumatoid arthritis, multiple sclerosis, Crohn's disease and lupus.

Kezar's guiding science dates back more than 10 years to Proteolix, a biotech then developing proteasome inhibitors for a range of indications. Onyx stepped in in 2009 to get its hands on what would become Kyprolis in a roughly $900 million buyout deal, bringing Proteolix's Christopher Kirk aboard as vice president of research to help steer development. Now Kirk is following the science to Kezar, signing on as the company's chief scientific officer as it focuses in on the immune system.

Beyond its top program, the company is working on a preclinical pipeline of treatments that target protein secretion, building on the same biological principles in hopes of developing a wide range of potential therapies.

"Protein secretion represents a fundamental process inside of nearly all cells and an untapped area of drug discovery," Kirk said in a statement. "Our approach allows for the generation of substrate selective inhibitors of secreted and transmembrane proteins. Essentially the target of every monoclonal antibody therapy is amenable to our small-molecule drug targeting approach."

Leading Kezar's efforts is CEO John Fowler, and the biotech's A round included investments from Morningside Venture, Cormorant Asset Management, EcoR1 Capital, 9W Capital Management, Omega Funds and Aju IB Investment.

- read the statement

Editor's note: An earlier version of this story misstated Christopher Kirk's role at Proteolix. We regret the error.