Two new drug therapies can significantly slow the advance of HIV in both the early and late stages of infection, giving new hope to patients with the virus that causes AIDS, according to two Duke studies released earlier this month.
In one finding, doctors announced the potentially ground-breaking effectiveness of T-20, a fusion inhibitor, which is part of the class of drugs that can successfully prevent the entry of HIV into human cells. Researchers in another study compared patients' response to several antiretroviral drug combinations, or cocktails, which attempt to slow the reproduction of viruses within cells, and found that some are far more efficient than others.
The researchers presented the studies at the 14th annual International AIDS Conference in Barcelona, Spain, held the week of July 8.
Dr. Dani Bolognesi headed the T-20 study, which grew out of the research he and other Duke professors pioneered in the early 1990s. The drug1s benefits come, he said, because HIV mutates in some patients to become immune to many of the 17 therapies currently on the market. By taking the unique approach of preventing the virus from ever entering cells, and combining T-20 with more common drugs, researchers greatly reduced HIV1s presence in patients.
"While these cocktails are effective, they are not without side-effects. Taking such strong drugs for a long period of time can be very damaging for a patient, and then the virus can re-emerge," said Bolognesi, who is now on leave from his position as professor of experimental surgery, working full-time to develop T-20 as chief executive officer of Trimeris, Inc. in Research Triangle Park. "Our drug doesn't really care whether the virus has developed resistance or not. It1s equally effective against naturally developed HIV strains and those that have evolved over time."
In one of the trials, the concentration of HIV in patients using T-20 fell to the recommended low levels in 37 percent of cases, compared to 16 percent of cases in which patients just took traditional drug cocktails.
The federal Food and Drug Administration recently placed T-20 on its fast-track list for approval within six months, and Bolognesi said it could be on the market within a year. In addition, he said Trimeris is making progress on an even stronger drug, T-1249, that may replace T-20 if HIV develops immunity to the latter.
On the opposite end of HIV treatment, patients who have never taken medication for the virus may now have a much better chance at longevity according to a study that examined the effectiveness of different cocktails. Dr. John Bartlett, professor of medicine, told the experts gathered in Barcelona that over three quarters of patients responded positively to at least one of the three cocktails tested.
A group using a combination of the antiretroviral drugs abacavir, lamivudine and nNRTI saw the most dramatic reduction in HIV copies per milliliter of blood, in some cases dropping from as high as 100,000 copies/mL to 50 copies/mL.
"Trying to find the best combination for patients is a challenge. It requires a controlled group, and a very large sample," Bartlett said.
The results represent analysis after 48 weeks of the study, and Bartlett said they will know more as trials continue.
A total of 291 patients in North and South America participated in the antiretroviral study, and about 1,000 patients on four continents were treated in the T-20 study. Bartlett noted the importance of using a diverse sample but also said clinical trials are an inexpensive way to bring treatment to developing nations.
Get The Chronicle straight to your inbox
Signup for our editorially curated, weekly newsletter. Cancel at any time.
About 41 million people worldwide are infected with HIV, and although only a few of them will ever have access to expensive drugs like T-20, Bartlett said that many researchers in Barcelona were optimistic about recent attempts to spread therapies.
"There was a very strong emphasis on HIV in the global community," Bartlett said. "For many people, an important access point to antiviral therapy may be through clinical trials."