FDA grants Vical orphan-drug designation

Vical Incorporated today announced that the Office of Orphan Products Development of the U.S. Food and Drug Administration (FDA) has designated the company's bivalent (two-plasmid) formulation of the company's vaccine against cytomegalovirus (CMV) as an orphan drug for the prevention of clinically significant CMV viremia, CMV disease and associated complications in at-risk hematopoietic cell transplant (HCT) and solid organ transplant (SOT) populations.

The vaccine is expected to enter Phase 2 human trials in HCT donor-recipients in the second half of 2005.

The Orphan Drug Act is intended to encourage development of products for rare diseases affecting fewer than 200,000 people in the United States. For products designated as orphan drugs, FDA will not approve other applications to market the same product for the same indication for a period of seven years after product approval. In addition to potential market protection, orphan-drug designation provides certain tax credits, opportunities for regulatory agency assistance on review of clinical protocols, and waiver of the Prescription Drug User Fee Act (PDUFA) filing fee.

"The potential benefits of orphan-drug designation offer substantial incentives for continued development of our CMV vaccine in the initial transplant indications," said Vijay B. Samant, Vical's President and Chief Executive Officer. "The opportunities for market exclusivity, financial and tax advantages, additional FDA guidance, and elimination of PDUFA fees support our efforts to address the serious unmet need to protect transplant patients from CMV. We may then be able to leverage success in the transplant market into a collaboration for a universal CMV vaccine indication to address the significant healthcare burden of congenitally-acquired CMV infection, which would not be covered by the orphan-drug designation."

CMV infection affects an estimated 30 to 60 percent of the estimated 29,000 patients undergoing HCT or SOT procedures in the United States annually, causing transplant rejection, serious illness and even death if untreated. Expensive antiviral drug therapy is used to control the disease, but does not eliminate the infection. Congenital CMV infection also affects one out of every hundred infants, and causes severe consequences in about 3,600 infants and death in about 400 each year in the United States.