JNJ-53718678 is a potent and orally available fusion inhibitor of the RSV virus, optimized from a prior oral inhibitor, BMS-433771. The prior inhibitor was challenged by moderate potency, suboptimal PK in preclinical species, limited lung distribution, and potential complications from CYP TDI due to an aminocyclopropyl moiety. The improved [...]

This month’s cover molecule, Pfizer’s PF-07321332 (nirmatrelvir, API of Paxlovid) is an oral, reversible covalent SARS-CoV-2 main protease inhibitor, which has been submitted to the FDA by Pfizer for emergency approval for Covid treatment. Interim data showed Paxlovid reducing Covid hospitalization and death by 89%. It was nominated for this month’s [...]

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 [...]

GSK2818713 is an HCV NS5A replication complex inhibitor with an interesting biphenylene linker. The crowded, hotly competitive NS5A space has led to a lot of creative chemical scaffolds including this one.

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 [...]