Camvia™ (maribavir)
More than 100,000 transplants are performed throughout the world annually; for each of these patients, one of the biggest medical concerns is the development of cytomegalovirus, or CMV, disease. Clinical studies involving Camvia™ (maribavir), an investigational product, suggest the drug may represent the first advancement in the field of CMV prevention in over a decade.
Background
maribavir is a novel Phase 3 antiviral compound in clinical development by ViroPharma for prevention of CMV disease in stem cell and solid organ transplant patients. Clinical data suggest that maribavir is a potent and selective, orally bioavailable antiviral drug with a unique mechanism of action against cytomegalovirus and a favorable early clinical tolerability 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, benzimidazole ribosides inhibit viral DNA assembly and inhibits egress of viral capsids from the nucleus of infected cells. Maribavir is active in vitro against strains of CMV that are resistant to commonly used anti-CMV drugs.
In Phase 2 clinical maribavir studies, data clearly demonstrated, among other outcomes, that prophylaxis with maribavir significantly reduced the incidence of CMV infection in this population. In addition to the favorable overall safety profile, there was no evidence of myelosuppression or renal toxicity at any of the doses tested. Thus, maribavir represents a promising investigational anti-CMV agent that may provide clinically significant advantages as compared to currently available therapies. The compound was granted orphan drug designation by the U.S. Food and Drug Administration in the US for prevention of cytomegalovirus viremia and disease in the populations at-risk in February 2007, and in Europe for cytomegalovirus (CMV) disease in patients with impaired cell-mediated immunity in November 2007. The links to these press releases can be found here and here.
Status
On July 5, 2007, ViroPharma announced the initiation of patient recruitment into a second pivotal Phase 3 study of maribavir. This study will evaluate the prophylactic use of maribavir in patients undergoing a liver transplant procedure. The press release announcing this initiation can be found here. The first Phase 3 study of maribavir was initiated in September 2006 in patients undergoing a stem cell transplant. The press release announcing this initiation can be found here.
On December 11, 2006, ViroPharma announced the presentation of results from the company’s Phase 2 evaluation of maribavir at the 48th Annual Meeting of the American Society of Hematology (ASH). The press release announcing these results can be found here.