ViroPharma Inc. recently announced the initiation of a phase II program. The phase II program will evaluate maribavir for the treatment of cytomegalovirus (CMV) infections in transplant recipients.
Two independent phase II studies will be conducted under the program. The first independent clinical study will include subjects who have asymptomatic CMV. ViroPharma intends to enroll 160 subjects who have CMV viremia but do not have CMV organ disease.
In this study, subjects cannot have CMV infection that is resistant to other anti-CMV agents. Patients in this study will be randomized to receive either oral maribavir (400mg, 800mg or 1200mg) or valganciclovir for up to 12 weeks. The study will monitor blood levels of CMV DNA.
The second study will include treatment-failed patients. ViroPharma is planning to enroll 120 subjects who have demonstrated CMV viremia with or without CMV organ disease. In the study, subjects will be randomized to receive one of the three dosages of oral maribavir for up to 24 weeks. This study will monitor blood levels of CMV DNA.
Maribavir has been granted orphan drug status in the US for the treatment of clinically significant CMV and disease in at-risk patients.
Apart from maribavir, ViroPharma is working on the development of other pipeline candidates like VP 20621 (management of C. difficile infection) and VP20629 (treatment of Friedreich’s Ataxia).
We currently have a Neutral recommendation on ViroPharma. The stock carries a Zacks #4 Rank (Sell rating) in the short-run. The company suffered a setback in April when the FDA denied the company’s March 2006 citizen petition related to the FDA’s proposed in vitro method for determining bioequivalence of abbreviated new drug applications (ANDAs) referencing Vancocin (vancomycin).
Moreover, generic players like Watson Pharma and Akorn have launched their generic versions of Vancocin. We expect rapid erosion in Vancocin sales given the entry of generic competition.