sisunatovir + itraconazole

**Sisunatovir + itraconazole** is an investigational combination of two small molecule drugs. *Sisunatovir* is a respiratory syncytial virus (RSV) fusion inhibitor that targets the RSV F protein, preventing viral entry into host cells. *Itraconazole* is an antifungal agent well-established in clinical use, acting primarily through inhibition of ergosterol synthesis in fungi, but also studied for its host-targeted antiviral effects, including impairing viral replication by inhibition of cholesterol transport and other host cellular pathways. The rationale for their combination would be to unite a direct-acting antiviral (sisunatovir) with a host-targeted agent (itraconazole) to potentially enhance antiviral activity, possibly lower doses, and reduce development of resistance. Current evidence for this combination is largely theoretical and investigational; there are no clinical trials or clinical approvals for the use of sisunatovir + itraconazole together, though combinations of similar classes (fusion inhibitors and host-targeted agents) are being explored in RSV and other viral diseases[2].