By Randall Osborne
West Coast Editor
Gilead Sciences Inc. said its HIV drug Viread will be on pharmacy shelves in days ¿ having won approval late Friday from the FDA, which said the company can label the treatment for all patients with the virus, not just those whose disease has quit responding to other drugs.
Viread (tenofovir disoproxil fumarate), which joins about 15 other HIV drugs on the market, is a nucleotide analogue reverse transcriptase inhibitor. It¿s the first such compound approved for HIV, which allows for once-daily dosing.
Clinical trials have shown Viread reduces HIV in the blood for up to 48 weeks when used with patients¿ existing antiviral regimens, and worked even in those patients who had developed resistance to their usual treatments.
¿This is a drug that will surprise some people,¿ said Eric Ende, an analyst with Banc of America Securities in New York. ¿It works extremely well in resistant patients.¿
Viread¿s once-daily dosing will prove a boon as well in the resistance area, he said.
¿A lot of the reason [HIV patients] tend to develop resistance is they can¿t comply with the complex regimens,¿ he said. ¿They¿re dosing with 20 pills a day sometimes.¿
Early this month, the Antiviral Drugs Advisory Committee of the Center for Drug Evaluation and Research came out divided on Viread. Nine members supported a restricted label for use only in treatment-experienced patients, seven voted for a label recommending it for treatment-naive patients, and two members abstained. (See BioWorld Today, Oct. 4, 2001.)
As it stands, the label will note that studies on which approval was based were in the treatment-experienced patients, so the risk-benefit ratio for others has not been determined. About 15,000 HIV patients of the total 350,000 in the U.S. are new to treatment each year.
Gilead also has a program to evaluate Viread in treatment-experienced pediatric patients.
¿We¿re in the process of initiating that,¿ said Amy Flood, manager of corporate communications for Gilead. ¿We¿ll have a pediatric formulation [for the trials] in the first quarter of next year.¿
The company also is further testing Viread in treatment-naive people living with HIV. A 96-week blinded trial, called Study 903, is comparing a treatment regimen of Viread, lamivudine (3TC) and efavirenz to a treatment regimen of stavudine (d4T), lamivudine and efavirenz in patients in the U.S., Europe and South America. Enrollment was completed in January with 601 patients.
¿We¿ll have data on the primary endpoint the first part of next year,¿ at the 48-week check point, Flood told BioWorld Today.
Resistance is slow to develop to Viread itself, Gilead said, noting that the drug has been given to more than 1,000 patients alone or in combination with other antiretrovirals for periods of 28 days to 143 weeks in clinical trials and in a compassionate-access study.
¿So far, we¿ve seen the [resistance] mutation is rare, and occurred in 3 percent of patients in pivotal studies,¿ Flood said. ¿It can also develop in the presence of other drugs, so it¿s not a definitive answer that it was attributable to Viread.¿
Flood said Viread will cost $4,135 per year. Ende put sales next year at $124 million, with peak sales at $500 million, noting the drug is especially beneficial for Gilead, since ¿they own the entire thing, both the U.S. and Europe.¿
Ende said Viread is priced ¿somewhat at the higher end,¿ but noted protease inhibitors are even more costly, at $6,000 to $6,500 a year.
Earlier this month, Gilead said the European Union¿s Committee for Proprietary Medicinal Products recommended granting marketing authorization for Viread in the 15 member states for patients 18 years and older experiencing early virological failure.
Gilead said it expects that authorization will be granted in early 2002, when the drug will be launched in the UK and Germany.
Launch in other EU states will be done on a country-by-country basis, as pricing and reimbursement are negotiated. Gilead has told analysts it expects that its beefed-up sales force will contact physicians writing prescriptions for as much as 85 percent of HIV treatments, wrote analyst Thomas Dietz, with Pacific Growth Equities, in a research note.
Gilead also has filed for approval of Viread in Australia, with approval expected in 2002, and more regulatory filings are expected in Switzerland, Brazil, Argentina and Canada.
Gilead¿s stock (NASDAQ:GILD) closed Monday at $65.55, down $2.13.