Chemical scaffold recycling: Structure-guided conversion of an HIV integrase inhibitor into a potent influenza virus RNA-dependent RNA polymerase inhibitor designed to minimize resistance potential.

Influenza is one of the leading causes of disease-related mortalities worldwide. Several strategies have been implemented during the past decades to hinder the replication cycle of influenza viruses, all of which have resulted in the emergence of resistant virus strains. The most recent example is baloxavir marboxil, where a single mutation in the active site of the target endonuclease domain of the RNA-dependent-RNA polymerase renders the recent FDA approved compound ∼1000-fold less effective. Raltegravir is a first-in-class HIV inhibitor that shows modest activity to the endonuclease. Here, we have used structure-guided approaches to create rationally designed derivative molecules that efficiently engage the endonuclease active site. The design strategy was driven by our previously published structures of endonuclease-substrate complexes, which allowed us to target functionally conserved residues and reduce the likelihood of resistance mutations. We succeeded in developing low nanomolar equipotent inhibitors of both wild-type and baloxavir-resistant endonuclease. We also developed macrocyclic versions of these inhibitors that engage the active site in the same manner as their 'open' counterparts but with reduced affinity. Structural analyses provide clear avenues for how to increase the affinity of these cyclic compounds.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Stephen White reports a relationship with Life Science Tennessee that includes: board membership. Zoran Rankovic reports a relationship with Revolution Medicines that includes: consulting or advisory. Zoran Rankovic reports a relationship with Orum Therapeutics that includes: consulting or advisory. Zoran Rankovic reports a relationship with Nyrada Inc that includes: consulting or advisory. Zoran Rankovic reports a relationship with Eli Lilly that includes: equity or stocks.
(Copyright © 2022. Published by Elsevier Masson SAS.)