The Food and Drug Administration has authorized pre-approval distribution of atavaquone (566C80) -- an experimental drug for treating Pneumocystis carinii pneumonia, a potentially life-threatening infection that often afflicts AIDS patients. The drug will be made available under a Treatment IND protocol that will grant access to the drug to physicians treating patients who have Pneumocystis carinii pneumonia and cannot tolerate treatment with trimethoprim-sulfa, a standard treatment for this condition.
Treatment IND regulations provide a mechanism that allows drug developers to provide pre-approval access to experimental drugs that are designed to treat serious and life-threatening conditions for which there are no satisfactory treatments. Drugs that are granted Treatment IND status must demonstrate through clinical testing that they may be efficacious. This is the 23rd drug to receive Treatment IND status since this program was formalized in 1987.
The Treatment IND for atavaquone (566C80) was based on clinical studies that indicated that the drug could be effective for patients with mild to moderate Pneumocystis carinii pneumonia. The drug will be made available under the treatment IND to patients with this condition who are intolerant or not responding to trimethoprim-sulfa therapy (there are two versions of this therapy which are commonly known by their trade names, Bactrim and Septra). More severely ill patients will be able to get the drug via a companion open label study. Although many patients can be successfully treated with trimethoprim-sulfa, a large number may experience allergic reactions to this drug.
Clinical trials comparing the efficacy of atavaquone (566C80) to Bactrim and Septra, as well as to intravenous pentamidine, the other standard therapy for Pneumocystis carinii pneumonia, have been conducted throughout the United States, Canada and Europe. These studies are continuing and will provide more clinical data on the new drug's long term safety and efficacy.
The most serious adverse effects of atavaquone (566C80) are severe rashes that have been experienced by a very small number of patients. Other, less serious, adverse reactions that have been reported include milder rashes, fever, various digestive problems and relatively minor blood abnormalities.
The Treatment IND and open study protocol for atavaquone (566C80) are being sponsored by the drug's developer, the Burroughs Wellcome Co. of Research Triangle Par, N.C. Physicians interested in enrolling their patients in the Treatment IND or open study protocol can contact the sponsor through a special hotline number, 1-800-755-2020.