ATI-2173 + tenofovir disoproxil fumarate + AB-729

This combination consists of **ATI-2173**, a liver-targeted prodrug of clevudine and active site polymerase inhibitor nucleotide (ASPIN), **tenofovir disoproxil fumarate**, a nucleoside reverse transcriptase inhibitor (NRTI) and chain-terminating nucleotide analogue, and **AB-729**, a small interfering RNA (siRNA) targeting hepatitis B surface antigen (HBsAg) mRNA. This regimen is being investigated for the treatment of chronic hepatitis B virus (HBV) infection, aiming for functional cure by combining inhibition of viral replication (ATI-2173, tenofovir disoproxil fumarate) and reduction of HBsAg production (AB-729). ATI-2173 is designed for strong liver targeting and reduced systemic clevudine exposure, providing potent and durable suppression of HBV DNA and cccDNA markers[1][2][3][4][5][7]. Tenofovir disoproxil fumarate is approved and widely used in HBV therapy. AB-729 is an siRNA conjugate in development that reduces circulating HBsAg. The combination harnesses complementary antiviral mechanisms to more profoundly suppress HBV replication and antigenemia than possible with monotherapy.