IPA-3 for COVID-19

IPA-3 may be beneficial for COVID-19 according to the studies below. COVID-19 involves the interplay of 500+ viral and host proteins and factors providing many therapeutic targets. Scientists have proposed 11,000+ potential treatments. c19early.org analyzes 220+ treatments. We have not reviewed IPA-3 in detail.
Porta et al., Targeting SARS-CoV-2 Non-Structural Proteins: A Blueprint for Next-Generation Small-Molecule Coronavirus Antivirals, Pharmaceutics, doi:10.3390/pharmaceutics18060693
The SARS-CoV-2 non-structural proteome remains the most clinically validated and strategically important landscape for direct-acting small-molecule antiviral drug discovery. The success of inhibitors targeting the main protease (Mpro, Nsp5) and RNA-dependent RNA polymerase (RdRp, Nsp12) has firmly established viral replication enzymes as tractable, druggable, and therapeutically relevant targets, while setting clear benchmarks for translational antiviral development. Building on this foundation, a second wave of non-structural protein (Nsp) targets has emerged with increasing translational promise, including the papain-like protease (PLpro), the bifunctional Nsp14 proofreading and capping machinery, Nsp16 2′-O-methyltransferase, Nsp13 helicase, and Nsp15 endoribonuclease. In parallel, additional components such as Nsp1 and the Mac1 domain of Nsp3 continue to expand the antiviral design space, although they remain at earlier stages of chemical validation. In this review, we comprehensively assess SARS-CoV-2 non-structural proteins through a medicinal chemistry and translational lens, with an emphasis on structural tractability, mechanism of action, quality of chemical matter, cellular and in vivo antiviral evidence, evolutionary conservation, resistance liabilities, and developability. Particular attention is given to the features that distinguish tool compounds from genuinely actionable leads and to the opportunities for rational combination regimens that extend beyond first-generation protease- and polymerase-centred therapy. Collectively, the non-structural proteome offers the strongest foundation for next-generation and potentially broader-spectrum coronavirus antivirals with improved resilience to viral evolution.
Chatziefthymiou et al., Identification, validation, and characterization of approved and investigational drugs interfering with the SARSCoV‐2 endoribonuclease Nsp15, Protein Science, doi:10.1002/pro.70156
AbstractSince the emergence of SARS‐CoV‐2 at the end of 2019, the virus has caused significant global health and economic disruptions. Despite the rapid development of antiviral vaccines and some approved treatments such as remdesivir and paxlovid, effective antiviral pharmacological treatments for COVID‐19 patients remain limited. This study explores Nsp15, a 3′‐uridylate‐specific RNA endonuclease, which has a critical role in immune system evasion and hence in escaping the innate immune sensors. We conducted a comprehensive drug repurposing screen and identified 44 compounds that showed more than 55% inhibition of Nsp15 activity in a real‐time fluorescence assay. A validation pipeline was employed to exclude unspecific interactions, and dose–response assays confirmed 29 compounds with an IC50 below 10 μM. Structural studies, including molecular docking and x‐ray crystallography, revealed key interactions of identified inhibitors, such as TAS‐103 and YM‐155, with the Nsp15 active site and other critical regions. Our findings show that the identified compounds, particularly those retaining potency under different assay conditions, could serve as promising hits for developing Nsp15 inhibitors. Additionally, the study emphasizes the potential of combination therapies targeting multiple viral processes to enhance treatment efficacy and reduce the risk of drug resistance. This research contributes to the ongoing efforts to develop effective antiviral therapies for SARS‐CoV‐2 and possibly other coronaviruses.