Washington Editor

Gilead Sciences Inc. is requesting FDA approval of a co-formulation combining Viread with Emtriva in a single pill dosed once daily to be taken with other antiretrovirals for the treatment of HIV.

The Foster City, Calif.-based company Monday said it simultaneously filed drug applications with the FDA and the European Agency for the Evaluation of Medicinal Products (EMEA). Action in the U.S. is expected by Jan. 12, 2005, while European action could take up to one year.

James Loduca, Gilead's manager of public affairs, told BioWorld Today the co-formulation drug is designed to be the backbone of HIV combination therapy. The company believes it will compete head to head with Combivir, a combination of AZT (zidovudine) and Epivir (lamivudine), made by London-based GlaxoSmithKline plc. Combivir is a single pill taken twice a day.

"Our drug will be AZT-free and it will be dosed once a day," Loduca said, adding that HIV drugs have greatly improved over the last decade, a time when AIDS patients often took up to 25 drugs a day to control their disease. However, there's a continuing need to simplify drug regimens and reduce treatment-related side effects commonly associated with HIV drug therapy.

Gilead's single tablet would contain 300 mg of Viread (tenofovir disoproxil fumarate) and 200 mg of Emtriva (emtricitabine). Viread, the first nucleotide reverse transcriptase inhibitor approved for HIV combination therapy, was cleared for marketing by the FDA in 2001 and by the EMEA in 2002. It is available as a single 300-mg tablet taken once daily. (See BioWorld Today, Oct. 30, 2001.)

Emtriva is a nucleoside reverse transcriptase inhibitor for HIV cleared for marketing by the FDA and EMEA in 2003. It is available as a single 200-mg capsule that also is taken once daily. (See BioWorld Today, July 3, 2003.)

Both medications work by blocking reverse transcriptase, an enzyme crucial for HIV replication. Following the approval of the fixed-dose co-formulation, each drug would continue to be sold individually, the company said.

Worldwide sales for Viread in 2003 were $566.5 million. Sales for Emtriva, approved mid-year in the U.S., totaled about $10 million. Guidance on sales of the combination product have not been issued.

Gilead believes many of the patients taking either Viread or Emtriva will transition to the fixed-dose combination.

The product will receive a trade name at launch, Loduca said.

Emtriva, also referred to as FTC or Coviracil, was developed by Triangle Pharmaceuticals Inc., a Durham, N.C.-based company that was acquired by Gilead for $464 million in a deal announced in late 2002. (See BioWorld Today, Dec. 5, 2002.)

Emtriva also is being studied in Phase III trials for hepatitis B.

Gilead's stock (NASDAQ:GILD) closed Monday at $56.33, down $1.17.