Ibacitabine

Ibacitabine (5-Iodo-2'-deoxycytidine) is a nucleoside analog that serves as a substrate for cytidine deaminase, with antiviral and antitumor activities. Ibacitabine is preferentially phosphorylated and activated by kinases specifically induced by herpesviruses, thereby being converted into its active form (IdUTP) and incorporated into viral DNA in infected cells. Ibacitabine can be used in the research of herpes simplex virus infection and herpetic keratitis^[1]. In Vitro:Ibacitabine potently inhibits herpes simplex virus replication in cell culture^[1].
Ibacitabine exhibits reduced cytotoxicity compared to IdUrd in baby hamster kidney cells lacking cytidine deaminase, and its toxicity in HEp-2 cells containing cytidine deaminase can be mitigated by co-administration of tetrahydouridine^[1].
Ibacitabine is selectively phosphorylated by herpes simplex virus-induced pyrimidine deoxyribonucleoside kinase, but poorly utilized by most mammalian cellular kinases, contributing to its selective antiviral activity^[1]. In Vivo:Ibacitabine suppresses the development of polyoma virus-induced tumors in newborn hamsters^[1].
Ibacitabine (topical; daily; 12 days) is therapeutically effective against herpes simplex virus keratitis in rabbits, with efficacy comparable to 5-iodo-2'-deoxyuridine (HY-B0307)^[1].