May 28, 2003

BIRMINGHAM, AL — Fuzeon (enfuvirtide), a new HIV therapy, has been shown effective in significantly reducing virus levels in patients who have developed multi-drug resistance to other HIV combination therapies, according to two studies published in the May 29 issue of the New England Journal of Medicine. The UAB 1917 Clinic, one of 48 sites that participated in the studies, pioneered development and testing of the new therapy, formerly called T-20, in 1997. Dr. Michael Saag, director of the 1917 Clinic, led the initial study.

The drug represents the first of a new class of HIV therapies known as fusion inhibitors that work by preventing the virus from infecting healthy cells. "Other therapies on the market work by preventing the virus from replicating once it enters cells while this drug is designed to block further spread of infection to new cells within the body," said Dr. Michael Kilby, medical director of the 1917 Clinic. "The clear advantage with T-20 is that because it has a different mechanism of action, it is sometimes effective for patients who have failed all other drug regimens."

Studies in the NEJM detail recent findings from two large clinical trials, which prompted the FDA to accelerate approval of the drug earlier this year. "Patients taking T-20, in combination with other already approved therapies, experienced a 10-fold drop in their levels of detectable virus compared with those who received the best available approved drugs but not T-20," Kilby said. "Also, on T-20, patients experienced few of the side effects common with other HIV treatments."

While encouraged by the drug's success, clinicians caution that Fuzeon is not for everyone. "It's a complex compound that is difficult to manufacture, therefore it's relatively expensive," Kilby said. "Also, it's not available in pill form. It must be administered twice daily by injection, which can be problematic for some. So, it is best reserved as a 'salvage' drug for patients who have run out of other options."

Fuzeon, manufactured by Trimeris and Roche Pharmaceuticals, opens the door for development of other viral entry inhibitors. The prospect of such therapies is discussed in a NEJM review, authored by Kilby and colleague Dr. Joseph J. Eron, with the department of medicine at the University of North Carolina at Chapel Hill. "The T-20 experience provides proof of concept that this novel class of anti-HIV drugs can have clinically meaningful activity," Kilby said. "It may be that, once they are further along in development, other types of viral entry inhibitors may be administered in combination with fusion inhibitors like T-20 for even more promising 'salvage' options for our treatment-experienced patients."

NOTE: The University of Alabama at Birmingham is a separate, independent campus from the University of Alabama, which is located in Tuscaloosa. Please use University of Alabama at Birmingham on first reference and UAB on second reference.