Maribavir
LIVTENCITY
What it isAn oral benzimidazole riboside antiviral that inhibits the cytomegalovirus UL97 protein kinase, blocking viral DNA replication, encapsidation, and nuclear egress.
Why this oneFDA-approved (Livtencity) for post-transplant CMV infection or disease that is refractory or resistant to ganciclovir/valganciclovir, foscarnet, or cidofovir.
What limits itIts UL97 mechanism antagonizes ganciclovir (avoid co-administration), resistance mutations can emerge on therapy, and as a CYP3A substrate it also raises tacrolimus concentrations.
FDA label
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| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Post-transplant CMV infection/disease refractory (with or without genotypic resistance) to ganciclovir, valganciclovir, foscarnet, or cidofovir | Adults & peds >=12 y and >=35 kg | 400 mg BID | 400 mg BID |
Renal No adjustment needed (mild-severe impairment); not studied in ESRD/dialysis
Hepatic No adjustment needed (Child-Pugh A/B); severe impairment not studied
Increase dose with concomitant CYP3A4 inducers: carbamazepine or rifabutin -> 800 mg BID; phenytoin or phenobarbital -> 1,200 mg BID
Instructions
- Take with or without food
- Tablets may be swallowed whole, dispersed, or crushed; dispersed tablets may be given by mouth or via NG/OG tube (French size >=10) in drinking water
- Prepared suspension may be stored at room temperature up to 8 h
Cautions
- May antagonize antiviral activity of ganciclovir/valganciclovir (inhibits pUL97 kinase activation) — coadministration not recommended
- Virologic failure during treatment and relapse post-treatment (usually within 4-8 wks after stopping): monitor CMV DNA and check for maribavir resistance if not responding; some pUL97 resistance substitutions confer cross-resistance to ganciclovir/valganciclovir
- Raises levels of narrow-window immunosuppressants (tacrolimus, cyclosporine, sirolimus, everolimus) — monitor drug levels frequently during, at initiation, and after discontinuation; adjust dose
- Strong CYP3A4 inducers reduce maribavir exposure — coadministration not recommended except with dose-adjusted carbamazepine/phenytoin; dose adjust with phenobarbital and rifabutin
Adverse reactions
- Most common (>10%): taste disturbance (46%), nausea, diarrhea, vomiting, fatigue
Pregnancy No adequate human data; decreased embryo-fetal survival in rats at exposures below the recommended human dose
Lactation Unknown whether present in milk or effects on infant/production; weigh benefits of breastfeeding vs need for drug
NO BOXED WARNINGS
Principal riskNo FDA boxed warning.
Cost, est. cash$300–$2,000/month
Generic entry2032 est.
Classes and tags
Clinical profile
Legacy pregnancy categoryNot assigned — PLLR-era drug
Defining liabilityAgent-specific renal, hepatic, hematologic, metabolic and drug-interaction toxicity.
Mechanism of action: Maribavir ballicule
