Hepatitis Delta Virus (HDV) is a co-infection that affects 5-6% of HBV patients. Compared to HBV infection alone, HBV/HDV co-infected patients are at risk of 2-3x faster onset of both cirrhosis and hepatocellular carcinoma
While there are an estimated 15-70 million HBV/HDV co-infected patients worldwide, HDV is classified as an orphan disease in both the U.S. and EU 1.
The active metabolite of ATI-2173 significantly decreased HDV RNA levels in woodchuck models of HBV/HDV co-infection. Conversely, neither TDF nor ETV have shown activity against HDV in animal models or human studies.