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FDA Approves New Dose Formulation of Viracept: 625 mg tablets
  Today, April 30, 2003, the Food and Drug Administration approved a new alternate dosing formulation of Viracept (nelfinavir mesylate). Viracept has been available in 50 mg oral powder and 250 mg tablets. The new formulation of 625 mg reduces the pill burden from five-250 mg tablets twice a day to two-625 mg tablets twice a day, potentially facilitating adherence to treatment regimens.
Viracept is a protease inhibitor indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents. The 250-mg tablet and oral powder received marketing approval in 1997 based on substantive evidence of efficacy and safety. Results of the bioequivalence study of the 250-mg tablet and the 625-mg tablet revealed increased bioavailability with the 625-mg formulation.
The sponsor, Agouron Pharmaceuticals, has submitted clinical safety and pharmacokinetic data to FDA providing evidence that the higher exposures do not pose a safety risk. However, diarrhea may be more common in patients receiving the 625 mg formulation. No efficacy information is contained in this submission because it is unlikely that a more bioavailable formulation would be less efficacious.
The efficacy of Viracept was previously demonstrated and reviewed in NDAs 20778/9.
Richard Klein Office of Special Health Issues
Food and Drug Administration
Agouron/Pfizer Press Release
SAN DIEGO, CA, May 1, 2003 - Agouron Pharmaceuticals, Inc., a Pfizer Company (NYSE:PFE), announced today that the U.S. Food and Drug Administration (FDA) has approved a 625 mg formulation of VIRACEPT (nelfinavir mesylate), cutting pill burden from five to two tablets twice a day. More than six years since it originally came to market, VIRACEPT remains one of the most prescribed protease inhibitors in the U.S. VIRACEPT, which is indicated for the treatment of HIV infection, should be used in combination with other antiretroviral agents.
In healthy volunteers receiving a single 1,250 mg dose, the 625 mg tablet demonstrates greater bioavailability than the 250 mg tablet formulation under fasted or fed conditions. Under fasted conditions (n= 27), the area under the curve (AUC) and Cmax were 34% and 24% higher, respectively, for the 625 mg tablets. In a relative bioavailability assessment under fed conditions (n = 28), the AUC was 24% higher for the 625 mg tablets; the Cmax was comparable for both formulations.
Recent data demonstrates that VIRACEPT should be taken with food to enhance blood levels. Specifically, data from the ATHENA study showed that when therapeutic drug monitoring (TDM) was used to identify suboptimal plasma nelfinavir concentrations, counseling to take VIRACEPT with food was an effective method of enhancing virologic response at one year.
"Moving from five tablets to two twice a day means it will be simpler and more convenient for patients to take this very important medication I trust," remarked Jay Dobkin, MD, Director of the AIDS Program at New York Presbyterian Hospital. "Given its unique resistance profile and the salvage options usually available, nelfinavir is attractive as an initial protease inhibitor choice. This new formulation will make compliance to that critical first treatment regimen even easier."
Studies are underway to evaluate the efficacy and safety of the VIRACEPT 625 mg tablet formulation. Currently, the VIRACEPT 250 mg tablet formulation demonstrates proven effectiveness and immunologic benefit, and it is anticipated that the greater bioavailability of the new 625 mg formulation, enhanced by adequate food intake, will optimize response.
"To help improve adherence, we felt a simplified dosing regimen was a critical next step for this proven therapy," commented Richard Ogden, PhD, Senior Director, Scientific Development, Agouron Pharmaceuticals, Inc. "The new tablets were designed for ease of use, and we hope that both new and current VIRACEPT users will find the switch effortless."
The 625 mg formulation of VIRACEPT will be available through retail and mail order pharmacies as well as institutional suppliers in early third quarter 2003. The recommended dosage for VIRACEPT is 1,250 mg (two 625 mg tablets or five 250 mg tablets) twice daily or 750 mg (three 250 mg tablets) three times daily. It is recommended that VIRACEPT should be taken with a meal when used in combination with other antiretroviral agents. VIRACEPT has been shown to be generally well tolerated. The most frequently reported adverse event among patients receiving VIRACEPT was diarrhea, which was generally of mild to moderate intensity. The frequency of VIRACEPT-associated diarrhea may be increased in patients receiving the 625 mg tablet.
Redistribution or accumulation of body fat may occur in patients receiving anti-retroviral therapy. The cause and long-term health effects of these conditions are not known at this time. VIRACEPT should not be used with certain medications. Taking certain other prescription and nonprescription drugs and supplements with VIRACEPT could create the potential for serious side effects that could be life threatening. In addition, some drugs may markedly reduce VIRACEPT plasma concentrations, resulting in suboptimal antiviral activity and subsequent emergence of drug resistance. Patients should always talk to their physician or healthcare provider before starting new medicines. HIV drugs do not cure HIV infection or prevent individuals from spreading the virus.
Agouron Pharmaceuticals, Inc. became a wholly owned subsidiary of Pfizer Inc in 2000. Pfizer Inc discovers, develops, manufactures and markets leading prescription medicines, for humans and animals, and many of the world’s best known over-the-counter consumer brands.
For more information, dial toll free 1-888-VIRACEPT (847-2237). VIRACEPT and Agouron are registered trademarks of Agouron Pharmaceuticals, Inc.
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