Wellcome Files First PLAs for Valaciclovir

Wellcome has filed Product License Applications for its new oral antiherpes drug Valtrex (valaciclovir) with regulatory authorities in 19 countries, including the USA and major European countries. The announcement comes soon after competitor SmithKline Beecham received approval to market its Famvir (famciclovir) in the USA (see also Marketletter July 11 and page 5).

Valaciclovir, an optical isomer of its parent drug Zovirax (aciclovir), is Wellcome's next-generation antiherpes drug; its superior bioavailability provides improved clinical efficacy and dosing, and the new drug is widely expected to share Zovirax' excellent safety profile. The new drug is a means for Wellcome to offset the potential advantage with famciclovir of a more favorable dosage regimen (three times daily for the SB drug compared to five times daily for aciclovir).

Wellcome is seeking licenses for the product initially for the treatment of herpes zoster or shingles, but in the near-term valaciclovir is also being tested for effi-cacy in treating or preventing recurrences of genital herpes and to suppress cytomegalovirus infections in immunocompromised patients.