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 [...]

AM-2-19 (SF001) is an analog of the notoriously toxic IV antifungal drug, amphotericin B (AmB). Compared with AmB, AM-2-19 is significantly less toxic against primary human cells and in mice, while more broadly active against fungal pathogens including antifungal drug-resistant strains. SF001 received Fast-Track Designation from the FDA in 2023 and has progressed to Ph. I clinical development. This article highlights the history of antifungal polyene natural products, a new mechanistic hypothesis for polyene antibiotic activity, and the design of 3rd generation Erg-specific polyenes.

QPX7728 is an ultrabroad-spectrum beta-lactamase inhibitor with activity against both serine and zinc metallo-beta-lactamases, in contrast to approved beta-lactamase inhibitors such as relebactam which are only active against serine metalloproteases. Interestingly, the boron of the molecule coordinates to serine hydroxyl groups in serine [...]

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 [...]

“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 [...]