HIV-1 Protease Inhibitor ASC09/Ritonavir

**Semantic type:** Pharmacologic Substance

**Definition:** A fixed combination agent containing ASC09, an orally bioavailable human immunodeficiency virus type 1 (HIV-1) protease inhibitor, and ritonavir, a potent CYP3A4 inhibitor, with potential activity against HIV and certain other RNA viruses. Upon oral administration of ASC09F, the HIV-1 protease inhibitor ASC09 selectively targets and binds to the active site of HIV-1 protease, and inhibits the dimerization and catalytic activity of HIV-1 protease. This inhibits the proteolytic cleavage of viral Gag and Gag-Pol polyproteins in HIV-infected cells. This inhibition leads to the production of immature, non-infectious viral proteins that are unable to form mature virions, and prevents HIV replication. In addition, ASC09 may also inhibit viral proteases from other RNA viruses, thereby preventing their replication. Ritonavir inhibits cytochrome P450 (CYP) 3A4 (CYP3A4)-mediated metabolism of ASC09, which is a CYP3A4 substrate. This leads to an increased concentration and half-life of ASC09 as compared to the administration of ASC09 without ritonavir.

**Synonyms:** - AS C09F - AS-C09F - ASC09F - HIV-1 Protease Inhibitor ASC09/Ritonavir ASC09F - Protease Inhibitor ASC09/Ritonavir