Alpha‐kinase 1 ( ALPK1 ) Agonist, DF ‐006 Demonstrates Potent Efficacy in Murine and Primary Human Hepatocyte Models of Hepatitis B

In the treatment of chronic hepatitis B (CHB) infection, stimulation of innate immunity may lead to hepatitis B virus (HBV) cure. Alpha-kinase 1 (ALPK1) is a pattern recognition receptor (PRR) that activates the NF-κB pathway and stimulates innate immunity. Here we characterized the preclinical anti-HBV efficacy of DF-006, an orally active agonist of ALPK1 currently in clinical development for CHB.In adeno-associated virus (AAV)-HBV mouse models and primary human hepatocytes (PHH) infected with HBV, we evaluated the antiviral efficacy of DF-006. In the mouse models, DF-006 rapidly reduced serum HBV DNA, HBsAg and HBeAg levels using doses as low as 0.08, 1 and 5 μg/kg, respectively. DF-006 in combination with the HBV nucleoside reverse transcriptase inhibitor, entecavir further reduced HBV DNA. Antiviral efficacy in mice was associated with an increase in immune cell infiltration and decrease of HBcAg, encapsidated pregenomic RNA (pgRNA) and covalently closed circular DNA (cccDNA) in liver. At sub-nanomolar concentrations, DF-006 also showed anti-HBV efficacy in PHH, with significant reductions of HBV DNA. Following dosing with DF-006, there was up-regulation of NF-κB-targeted genes that are involved in innate immunity.DF-006 was efficacious in mouse and primary human hepatocyte models of HBV without any indications of overt toxicity. In mice, DF-006 localized primarily to the liver where it potently activated innate immunity. The transcriptional response in mouse liver provides insights into mechanisms that mediate anti-HBV efficacy by DF-006.