Synonyms: AT-527 | AT527 | RO-7496998 | RO7496998

Compound class: Synthetic organic

Comment: AT-527 is the orally bioavailable hemi-sulfate salt of AT-511, which is a direct-acting antiviral compound that disrupts activity of the viral RNA polymerase [1]. It was originally developed to combat hepatitis C (HCV) infection, but has been redeployed for SARS-CoV-2. Chemically AT-527 is a phosphoramidate purine nucleotide and it is metabolised to a biologically active guanosine triphosphate analogue in vivo. Preclinical results showing pan-genotype activity against HCV were published in early 2020 [2]. In October 2020 anti-SARS-CoV-2 activity was reported in preprint format [3], which converted to full peer reviewed publication in March 2021 [4].

AT-527 was developed by Atea Pharmaceuticals [5]. In October 2020 it was announced that Roche were purchasing the rights to AT-527 (and gave it the research code RO7496998) outside of the US. In the same press release, it was revealed that AT-527 would be evaluated in Phase 3 trial in early 2021 to determine its efficacy as an early treatment for COVID-19 in non-hospitalised patients.

This is a complex molecule with 5 stereo-centres, so there are several CIDs with the same connectivity in PubChem. We chose to represent the molecule from CID 122527275 as it is linked to a FDA UNique Ingredient Identifier (UNII) code. This CID represents the parent molecule. For the hemi-sulfate salt structure see PubChem CID 155926085.