CRV431 + tenofovir disoproxil fumarate

**CRV431 + tenofovir disoproxil fumarate** is a combination of two antiviral agents investigated for the treatment of chronic hepatitis B virus (HBV) infection. **CRV431** is a clinical-stage, small-molecule cyclophilin inhibitor that acts by blocking cyclophilin isomerase activity, thereby disrupting critical host-virus interactions necessary for HBV replication, including inhibition of HBx protein function and viral DNA maintenance[3][1][2][5]. **Tenofovir disoproxil fumarate** is a nucleotide analog reverse transcriptase inhibitor (NRTI) that prevents viral replication by inhibiting HBV DNA polymerase and reverse transcriptase. The combination aims to provide complementary mechanisms to lower HBV replication, decrease viral markers (DNA, HBsAg, HBeAg), and potentially reduce liver fibrosis and tumor burden.