ViroPharma Initiates Phase 3 Study of CAMVIA(TM) (maribavir) in Liver Transplant Patients
- Category: Small Molecules
- Published on Friday, 06 July 2007 04:00
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EXTON, PA, USA | July 5, 2007 | ViroPharma Incorporated (Nasdaq: VPHM) today announced that the recently initiated second Phase 3 clinical study of CAMVIA(TM) (maribavir) in transplant patients is now open to patient recruitment. This study will evaluate the prophylactic use of CAMVIA in patients undergoing a liver transplant procedure, and will be conducted in up to 60 U.S. transplant centers. The first Phase 3 study of CAMVIA was initiated in September 2006 in patients undergoing a stem cell transplant.
ViroPharma's Phase 3 liver transplant study will compare the efficacy, safety and tolerability of prophylactic use of CAMVIA versus oral ganciclovir when administered for up to 14 weeks for the prevention of cytomegalovirus disease in recipients of orthotopic liver transplants at high risk of developing CMV disease. The study also will evaluate the pharmacokinetics of CAMVIA in this subject population.
"We have made great progress with CAMVIA in the last 12 months; the initiation of this second Phase 3 study is our latest milestone as we work towards our goal of making this important drug available for the more than 120,000 transplant patients throughout the world who are at risk of deadly CMV disease," commented Colin Broom, M.D., ViroPharma's chief scientific officer. "The excellent CAMVIA Phase 2 data presented at the 2006 ASH meeting encourage us as we execute on our comprehensive Phase 3 program in transplant patients."
Phase 3 Liver Transplant Study Design
This Phase 3 study is a randomized, double-blind, multicenter study intended to enroll over 300 subjects who have undergone liver transplantation and are at high-risk of developing CMV disease (i.e., donor CMV seropositive / recipient CMV seronegative). Following transplantation, eligible subjects will be randomized to receive CAMVIA 100mg BID or oral ganciclovir 1,000mg TID in a 1:1 allocation ratio for up to 14 weeks. If CMV disease, defined as symptomatic CMV infection or CMV organ disease, occurs during the study drug administration period, study drug will be discontinued and the subject will be managed according to standard CMV treatment practices at the transplant center.
The primary efficacy endpoint is the incidence of CMV disease (either symptomatic CMV infection or CMV organ disease) within 6 months post transplantation, which is expected to be approximately 12 percent in the oral ganciclovir arm of the study, based on data from published literature. A number of key secondary endpoints have been identified and assessment of these endpoints will play an important part in assessing the clinical benefit of CAMVIA. These secondary endpoints include time to onset of CMV infection and disease; the incidence and time to onset of anti-CMV therapy; and survival without CMV infection or disease; in addition to the incidence of adverse effects that limit the use of current therapies, including suppression of bone marrow function.
CAMVIA's antiviral activity and tolerability were elucidated in a Phase 2 study designed to assess the rate of CMV reactivation in patients undergoing allogeneic stem cell transplantation. The press release announcing the presentation of the data at the 2006 American Society of Hematology meeting can be found at the following URL: http://phx.corporate- ir.net/phoenix.zhtml?c=92320&p=irol-researchNewsArticle&ID=941183&highlight= (to ensure proper link, please copy and paste full address into browser)
CAMVIA(TM) (maribavir) is a potent and selective, orally bioavailable Phase 3 antiviral drug with a unique mechanism of action against cytomegalovirus and a favorable early clinical safety profile. It is a potent member of a new class of drugs called benzimidazole ribosides. Unlike currently available anti-CMV agents that inhibit CMV DNA polymerase, CAMVIA inhibits viral DNA assembly and inhibits egress of viral capsids from the nucleus of infected cells. CAMVIA is active in vitro against strains of CMV that are resistant to commonly used anti-CMV drugs.
CMV is a member of the herpes virus group, which includes the viruses that cause chicken pox, mononucleosis, herpes labialis (cold sores), and herpes genitalis (genital herpes). Like other herpes viruses, CMV has the ability to remain dormant in the body for long periods of time. Human CMV infection rates average between 50 percent and 85 percent of adults in the U.S. by 40 years of age, but in healthy adults causes little to no apparent illness. However, in immunocompromised individuals including cancer patients, HIV patients, and transplant patients, and in children born with primary CMV infection, CMV can lead to serious disease or death. Patients who are immunosuppressed following hematopoietic stem cell (bone marrow) or solid organ transplantation are at high risk of CMV infection. In these patients, CMV can lead to severe conditions such as pneumonitis or hepatitis, or to complications such as acute or chronic rejection of a transplanted organ. While currently available systemic anti-CMV agents are effective against the virus, their use is limited by toxicities, most notably bone marrow suppression and renal impairment.
About ViroPharma Incorporated
ViroPharma Incorporated is a biopharmaceutical company dedicated to the development and commercialization of products that address serious diseases treated by physician specialists and in hospital settings. ViroPharma commercializes Vancocin(R), approved for oral administration for treatment of antibiotic-associated pseudomembranous colitis caused by Clostridium difficile and enterocolitis caused by Staphylococcus aureus, including methicillin- resistant strains (for prescribing information, please download the package insert at http://www.viropharma.com/docs/Vancocin_pi_2007.htm ). ViroPharma currently focuses its drug development activities in viral diseases including cytomegalovirus (CMV) and hepatitis C (HCV). For more information on ViroPharma, visit the company's website at http://www.viropharma.com .
Certain statements in this press release may contain forward-looking statements that involve a number of risks and uncertainties, including those relating to our hope that CAMVIA could be a very important drug to market for the 120,000-plus transplant patients throughout the world at risk of deadly CMV disease and the expected incidence of CMV disease within 6 months post- transplant the oral ganciclovir arm of the study. Our actual results could differ materially from those results expressed in, or implied by, these forward-looking statements. The development and commercialization of pharmaceutical products is subject to risks and uncertainties. Further testing such as the planned Phase 3 clinical trials, may not support any or all of the statements in this press release. The antiviral and tolerability data that were elucidated in our Phase 2 study designed to assess the rate of CMV reactivation in patients undergoing allogeneic stem cell transplantation may not be predictive of the results of our Phase 3 programs in allogeneic stem cell transplantation or liver transplant patients and further testing such as the ongoing Phase 3 clinical studies may not support any or all of the statements in this press release. There can be no assurance that that our Phase 3 programs will yield positive results, that the FDA or other regulatory authorities will not require additional or unanticipated studies or clinical trial outcomes before granting regulatory approval, or that ViroPharma will be successful in gaining regulatory approval of CAMVIA in the US or other jurisdictions. These factors, and other factors, including, but not limited to those described in ViroPharma's quarterly report on Form 10-Q for the quarter ended March 31, 2007 filed with the Securities and Exchange Commission, could cause future results to differ materially from the expectations expressed in this press release. The forward-looking statements contained in this press release may become outdated over time. ViroPharma does not assume any responsibility for updating any forward-looking statements.
SOURCE: ViroPharma Incorporated