See the DrugPatentWatch profile for Maribavir
What is maribavir and how does it work against CMV?
Maribavir is an oral inhibitor of human cytomegalovirus (CMV) that targets the virus’ UL97 kinase (often referred to as “PUL97” in CMV literature and drug discussions) [1]. By inhibiting UL97/PUL97, it disrupts CMV replication steps that depend on UL97 kinase activity [1].
Is maribavir competitive with ATP?
Maribavir is described as a UL97 kinase inhibitor, and UL97 is a kinase that uses ATP to phosphorylate its substrates [1]. Based on how kinase inhibitors are typically classified and discussed in this context, maribavir is expected to act as an ATP-site (ATP-competitive) inhibitor of UL97, meaning it binds the kinase domain in a way that interferes with ATP-dependent activity [1].
How does “ATP-competitive” binding affect potency or resistance?
For ATP-competitive kinase inhibitors, drug effectiveness can depend on how the inhibitor interacts with ATP-binding within the kinase pocket, including whether the inhibitor can still bind when mutations alter the pocket. For UL97-targeting antivirals, resistance is generally associated with changes in UL97 that reduce inhibitor binding while preserving enough kinase function for viral replication [1].
What does the evidence say specifically for UL97/PUL97?
Maribavir’s mechanism is consistently tied to inhibiting the UL97 kinase activity in CMV [1]. The ATP-competitive claim (binding at the ATP site) is commonly used in explanations of how UL97 kinase inhibitors block phosphorylation reactions that require ATP [1], but exact mechanistic confirmation (for example, by direct binding kinetics or crystallography in a specific publication) is not provided in the single source available here.
Practical takeaway if you are comparing kinase inhibitors
If your goal is to compare maribavir to other UL97/PUL97-targeting candidates, the key differentiator is the binding mode (ATP-site vs non-ATP/site). ATP-competitive inhibitors can show different resistance profiles than inhibitors that bind elsewhere on the kinase domain, because pocket changes from resistance mutations can affect ATP-site binding differently [1].
Sources
- https://en.wikipedia.org/wiki/Maribavir