“compound 9” is an investigational prodrug of pibrentasvir (ABT-530), a key component of AbbVie’s marketed HCV combination Mavyret. Pibrentasvir (PIB) is the largest approved oral small molecule since 1983 (MW = 1113, not including the peptide semaglutide at MW = 4113), and came with some solubility issues (aq. sol. pH 7 = <0.0001 mg/mL). The [...]

A Ph. II liver-targeting HBV core protein modulator optimized for ADMET properties. Linvencorvir (RG7907), a novel HBV core protein allosteric modulator, offers a promising treatment option for chronic hepatitis B which affects 296 million people globally. It possesses an interesting glue-like mechanism that causes the HBV core protein to [...]

Despite the remarkable emergence of HAART in the 1990s, the fight against HIV infection is by no means finished. At the ACS Fall 2024 meeting in Denver, CO, Gilead Sciences presented the structure and discovery story of elunonavir (GS-1156), a novel HIV protease inhibitor with remarkable metabolic stability and a human half-life exceeding two weeks. Based on BMS’ atazanavir, the compound incorporates structural elements inspired by Gilead’s HCV NS5A inhibitor program which led to ledipasvir, as “stabilizer” motifs to avoid the extensive CYP metabolism seen in current inhibitors.

AL-611 is a prodrug to a nucleoside inhibitor of HCV NS5B polymerase. While there have been very successful nucleoside drugs (e.g. sofosbuvir), several nucleoside inhibitors of HCV previously failed in the clinic due to severe toxicities, in some cases due to incorporation of the nucleosides into host RNA. The Janssen Biopharma (formerly [...]

ASP5286 is an analog of the natural product cyclosporin A that maintains the anti-HCV activity of cyclosporin A by binding to cyclophilin, but was optimized to be less immunosuppresive than cyclosporin A. The macrocycle was identified through semisynthetic derivitization of a related natural product, FR901459. The Astellas team was able to [...]