FDA Approves First Drug in New Class of HIV Treatments
The Food and Drug Administration (FDA) today announced the accelerated approval of Fuzeon (enfuvirtide) for use in combination with other anti-HIV medications to treat advanced HIV-1 infection in adults and children ages 6 years and older.
"The accelerated approval of this new drug should provide new hope for those suffering from advanced HIV infection," Health and Human Services Secretary Tommy G. Thompson said. "While we work aggressively to prevent new HIV infections across the country, we also will continue to review potential new treatments so that drugs which are proven safe and effective are made available as quickly as possible to those Americans who could benefit from them."
FDA's accelerated approval of Fuzeon makes it the first product in a new class of medications called fusion inhibitors to receive marketing approval anywhere in the world. Drugs in this class interfere with the entry of HIV-1 into cells by inhibiting the fusion of viral and cellular membranes. This inhibition blocks the virus' ability to infect certain components of the immune system.
"Fuzeon adds an important dimension to our armamentarium of anti-HIV treatments. By affecting viral spread in a different way from existing medications, it helps reduce viral loads, which has been shown to slow HIV progression in patients who have developed resistance to currently available medications," said Commissioner of Food and Drugs Mark B. McClellan, M.D., Ph.D.
According to the U.S. Centers for Disease Control and Prevention (CDC), there are an estimated 850,000 to 950,000 people currently living with HIV in the U.S., with approximately 40,000 new HIV infections occurring in the U.S. every year. A significant percentage of patients with chronic HIV have developed infection resistant to many of the existing medications.
Since HIV must be treated with a combination of medications to be effective, Fuzeon can be used as part of a medication regimen in patients for whom there are limited options. Fuzeon should only be used in patients who have previously used other anti-HIV medications and have ongoing evidence of viral replication. Fuzeon is administered as a subcutaneous injection (i.e., a "shot" underneath the skin).
FDA based its accelerated approval of Fuzeon on an analysis of six months of data from two ongoing clinical studies of Fuzeon involving approximately 1,000 patients. The data from this analysis showed that the addition of Fuzeon to a combination of other anti-HIV medications reduced the level or "load" of HIV infection in the blood more than the use of the combination of anti-HIV medications alone. The long-term effects of Fuzeon are not known at this time, but are being evaluated by the ongoing clinical studies.
The approved labeling for Fuzeon warns physicians to carefully monitor patients for signs and symptoms of pneumonia. Although bacterial pneumonia was uncommon in clinical study participants, more patients treated with Fuzeon developed bacterial pneumonia than did patients who did not receive Fuzeon. Patients receiving Fuzeon are advised to seek medical evaluation immediately if they develop signs or symptoms suggestive of pneumonia such as cough with fever, rapid breathing and shortness of breath.
In addition, Fuzeon can cause both serious systemic allergic reactions and local skin reactions at the site of injection.
Symptoms of a serious systemic allergic reaction with Fuzeon can include: trouble breathing, fever and skin rash, chills, vomiting and low blood pressure. Patients taking Fuzeon should contact their healthcare provider right away if they get any of these symptoms.
Local skin reactions from Fuzeon injections are common, occur in almost all patients, and may be painful. Patients must be careful that their skin does not become infected at the site of injection.
Accelerated approval is a regulatory mechanism that speeds approvals of drugs for people with serious or life-threatening illnesses. FDA bases accelerated approval for a product on laboratory markers such as CD4 cell counts and viral load, rather than on clinical endpoints such as delay in death or reduction in opportunistic infections. FDA may withdraw the approval of products granted accelerated approval if post-marketing studies fail to verify clinical benefits.
Roche Pharmaceuticals of Nutley, N.J., has licensed the product from Trimeris Inc. of Durham, N.C., and will distribute Fuzeon.