When Virtual Screening Yields Inactive Drugs: Dealing with False Theoretical Friends

The search of antivirals against SARS-CoV-2 in available libraries of compounds was initiated as soon as WHO announced that the coronavirus outbreak became a pandemic. That pivotal task has been conducted by both experimental groups in wet-labs as well as by theoretical chemists in supercomputing centers. The combination of biochemical and clinical intuitions yields first to remdesivir, a broad-spectrum antiviral that remains as the standard solution for the treatment of severe cases, while paxlovid, molnupiravir and fluvoxamine have been recently proposed as oral alternatives. Unfortunately, the intensive publication of standard virtual screening (VS) simulations might be not the best strategy to increase that short list of antivirals. This contribution joins theory and biological assays to rescore massive VS. Our goal is to critically assess pros and cons of using molecular models for drug repurposing.