Fuzeon May Be of Greatest Benefit to People With Less Drug Resistance, Study Says
HIV-positive individuals who have "lesser degrees" of drug resistance may benefit even more from the new fusion inhibitor Fuzeon than people who have developed a more broad resistance to antiretrovirals, according to a study presented this weekend at the Interscience Conference on Antimicrobial Agents and Chemotherapy in San Diego, the Wall Street Journal reports (Chase, Wall Street Journal, 9/30). Fuzeon, formerly known as T-20, is the first in a new class of antiretroviral drugs called fusion inhibitors, which are designed to prevent HIV from entering cells. The drug, which was developed by Roche and Trimeris, was developed for patients who have drug-resistant strains of the virus and is intended to be administered in combination with other antiretroviral drugs (Kaiser Daily HIV/AIDS Report, 9/18). Fuzeon was originally "billed as a solution for patients running out of treatment options," but according to the study of 491 patients, it may work "even better" on patients with lesser degrees of drug resistance, the Journal reports. In the study, the patients were divided into four groups based on their "varying levels of response to standard AIDS drugs." One group of patients with "highly resistant virus" was given individually tailored combination antiretroviral therapy, while a second group of highly resistant patients was given combination therapy plus Fuzeon. Two groups of patients with less resistance were also given combination therapy with one group receiving Fuzeon as part of the combination. After 24 weeks, the group with less resistance that had received Fuzeon in addition to combination therapy showed the greatest decline in viral load, with some patients seeing declines from 100,000 virus particles per milliliter of blood to 501 particles per milliliter, according to Roche and Trimeris. The drug companies this month asked the FDA for marketing approval for Fuzeon. Although the companies have not yet set a price for the drug, analysts estimate that the cost could be as much as $12,000 to $15,000 per year because of the drug's complex manufacturing process. Roche and Trimeris are also already developing a second-generation version of Fuzeon, known as T-1249, "designed to have more potency, a longer half-life in the blood and more activity against different kinds of HIV, so that it can block viruses that become resistant to Fuzeon," Dani Bolognesi, CEO of Trimeris, said (Wall Street Journal, 9/30).
Valtrex May Reduce Spread of Herpes
Also at the conference, officials from GlaxoSmithKline released a study that
demonstrated that a once daily dose of the antiviral drug Valtrex can cut transmission of the viruses that cause genital herpes by up to 77% in heterosexual couples, the Journal reports. Genital herpes, which is caused by one of two viruses -- HSV-1 or HSV-2 -- is not life-threatening, but it is not curable. The infection is characterized by outbreaks of open lesions in the genital area, which are painful and can facilitate HIV transmission. The problem is particularly acute in Africa, where some countries have adult HSV-2 infection rates of 70% or higher. The study, which involved 1,484 heterosexual couples, half of whom were given Valtrex, marks the first time a study has shown that the drug may actually prevent HSV transmission. Valtrex is currently approved only for the treatment of genital herpes lesions. GSK officials said they plan to seek approval to market the drug as a means of reducing HSV transmission (Naik, Wall Street Journal, 9/30).