The startup is in a crowded field of drugmakers trying to develop hepatitis B treatments.
- Bluejay Therapeutics, a biotechnology startup developing treatments for hepatitis B, has raised $41 million in a Series B round led by Arkin Bio Ventures, the company announced this week.
- The company has two research programs licensed from Novartis that are close to clinical trials: an antibody targeting the virus and an oral drug that could be used in combination for some patients.
- Both small biotech companies and big pharmaceutical firms are working to develop new hepatitis B drugs to complement vaccination. Treatments could help better control the virus in chronically infected individuals.
Hundreds of millions of people worldwide have been infected at one point by hepatitis B, and an estimated 820,000 people died from the virus in 2019, according to the World Health Organization.
While a vaccine exists to prevent transmission of the virus, it is still the most common liver infection in the world. About 300 million people live with chronic hepatitis B infection, according to WHO, which raises the risk of cirrhosis and liver cancer.
The Food and Drug Administration has approved some drugs to treat chronic hepatitis B infections, but they must be taken chronically to prevent the virus’ replication. Gilead Sciences’ Viread and Vemlidy are two commonly used antivirals.
Bluejay’s lead research program is an antibody-drug designed to reduce the amount of hepatitis B surface antigen, a protein the virus uses to gain entry to liver cells.
Its other research program, the small molecule, is meant to prevent hepatitis B RNA and related proteins from forming in infected liver cells. Bluejay envisions the drugs being used together to increase functional cure rates in most patients.
However, some chronically infected individuals may have undetectable levels of surface antigen after receiving the antibody-drug and, as a result, might not need the oral medicine.
Founder Keting Chu launched Bluejay in 2019 after previous stints leading biotech startups and working as a partner at Silicon Valley venture capital firms. She raised a $20 million Series A round in 2020.
Working on a hepatitis B drug is the latest stage of a lifelong interest for Chu, who first encountered infected patients while training as a doctor in China in the late 1970s.
Chu moved to the U.S. in 1989 to pursue a doctorate in microbiology and immunology at the University of California, San Francisco. In the Bay Area, she met her future husband William Robinson, the Stanford Medicine researcher who isolated the genome of the virus that causes hepatitis B.
It was also where she met William Rutter, one of the scientists who developed the first hepatitis B vaccine with Chiron and Merck & Co. Rutter is now one of Bluejay’s investors and sits on its board of directors.
“It’s everyone’s homecoming trying to get a functional cure out there,” Chu said.
A handful of drug developers are working on programs to treat chronic liver infection, including Arrowhead Pharmaceuticals, Dicerna Pharmaceuticals, Vir Biotechnology and Arbutus Biopharma. All four companies are already in clinical trials. The first two have attracted partnerships from Johnson & Johnson and Roche, respectively.
Many of the drugs they’re developing rely on RNA interference, a drug-making technique that “silences” genes from making disease-causing proteins. Other drug candidates use nucleoside analogues or capsid inhibitors to reduce the amount of virus produced in the body.