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 [...]

Pfizer’s PF-07321332 (API of Paxlovid) is an oral, reversible covalent SARS-CoV-2 main protease inhibitor, which received emergency use authorization from the FDA for Covid treatment at the end of 2021. Clinical data showed Paxlovid reducing Covid hospitalization and death by 89%. It was nominated for November’s cover by Mike Koehler [...]

Recently, Novartis disclosed a new class of brain-penetrant, covalent agents against kinetoplastid parasites in Science. Kinetoplastid parasites cause Chagas disease (T. cruzi), sleeping sickness (T. brucei), and leishmaniasis (Leishmania), but there are few effective treatment options, especially for infections in the brain (e.g. stage II sleeping sickness).

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.

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 [...]