Surrozen, a biotech targeting the Wnt signaling pathway, reeled in a $50 million series B round, funding that will propel its antibody programs in liver disease and build out its platform into other areas where modulating that pathway might be useful.
The San Francisco biotech is trying to tap into Wnt (rhymes with mint) to come up with regenerative medicines, and Horizons Ventures, Hartford HealthCare Endowment, NS Investment, The Column Group and other existing investors are backing its mission.
“There are many tissues in the body where we know there are Wnt-responsive stem cells. … From the retina, to the brain, to the GI tract, to the liver, there are very specific stem cells known to both participate in tissue regeneration upon injury and to be self-renewing,” CEO Craig Parker said back in January at the J.P. Morgan Healthcare Conference.
It’s looking first at liver disease, despite how crowded the space has gotten, because it sees a niche for itself in patients on track to progress to liver failure.
“A lot of drugs being investigated for NASH—some anti-inflammatory, some anti-fibrotic—may prevent further damage and halt disease progression, but they won’t fix what damage has already been done... There is still a large unmet need of patients who have progressed to liver failure, which is the terminal point of all these diseases, including hepatitis C and alcoholic hepatitis,” Parker said.
“We think that failure is where we can fit in.”
With two Wnt-modulating platforms, San Francisco-based Surrozen is looking to stimulate stem cells in target tissue—in this case to create “healthy-looking and healthy-acting" liver cells, restore liver function and reverse fibrosis. The company is still figuring out which liver disease it wants to aim for first and hopes to nominate a candidate for liver disease this year.
Surrozen has developed two bispecific antibody platforms that could upregulate Wnt signaling. One mimics Wnt and directly stimulates Wnt signaling by binding to the same receptors that Wnt ligands do. The second mimics R-spondin, a protein that interacts with Wnt, and regulates Wnt signaling indirectly. Surrozen pursues both approaches simultaneously when it starts looking into a new disease area to determine which is better for a specific type of tissue injury, Parker said.
The company hasn't picked which diseases it wants to expand into just yet, but it is actively investigating lung and kidney disease, as well as gastrointestinal and retinal disease.
“All of these would be diseases that are characterized by some tissue injury, and—as with cirrhosis in the liver and ultimately liver failure—the inability of that organ to regenerate enough tissue to function normally,” Parker said.
Surrozen thinks liver disease is one area in which it could go it alone, but Parker acknowledges that there are numerous tissue types it could go into, putting partnerships on the table.
“I think it would be hard to do all of those ourselves, so we are discussing collaborations with potential partners. I think, ideally, we’d have some programs that we thought were viable to do ourselves... and have other programs that would benefit from having a corporate partner,” he said.