When a field is besieged by failures, small forward as look great triumphs. This is the case with the last effort to protect women at high risk of HIV infection. Two largest test a vaginal ring that slowly secretes an antiretroviral drug in the vagina have found that it reduced infection of about 30%. The placebo-controlled trials involved a total of 4,500 women in four countries in sub-Saharan Africa. "It's a huge win," said Sharon Hillier, a specialist in infectious diseases of reproduction at the University of Pittsburgh in Pennsylvania, who helped coordinate ASPIRE, the largest of the two studies and conducted trials of . Similar interventions have failed
others who are not involved in the studies are measured "the good news is the tests provide a consistent conclusion. the ring provided modest protection" says Mitchell Warren, head of AVAC, a nonprofit in New York that advocates for HIV prevention. "But it's oh so modest."
along Researchers have attempted to develop a preventive HIV specifically for women. But the most promising candidate compounds called vaginal microbicides that thwart the virus on the site of infection have failed repeatedly in clinical trials. "This [set of studies] was the last hope for Microbicides in many ways," says Thomas Hope Feinberg School of Medicine at Northwestern University of Chicago, Illinois. Hope, who was not involved with the new study, said. "I expected the results to be depressing"
The ring, a silicon band that releases an experimental antiretroviral called dapivirine, was tested South Africa, Malawi, Uganda and Zimbabwe, among 18 to 45 years. the ASPIRE trial found 27% overall efficiency, while the second trial called the Ring Study-found efficiency of 31%.
But the ring did not make nearly as much for women aged 18 to 21, giving a simple protection of 15% in the study and had absolutely no ring in the ASPIRE trial. in women over 21, however, the efficiency reached 56% in ASPIRE, Ring the study showed 37% protection in the older group No serious safety concerns emerged in both studies
.. the results were presented to the public for the first time today at a press conference at the Conference on retroviruses and opportunistic infections (CROI) in Boston. ASPIRE results also appear in a paper published online today in The New England Journal of Medicine . Researchers from both trials will present their findings in more detail later this week in the scientific sessions at CROI.
Each holding-study in parallel to speed regulatory approval cost of about $ 72 million. The National Institute of Allergy and Infectious Diseases of the United States provided the main funding ASPIRE, which has been run by the Network for microbicide trials that Hillier leaders. The International Partnership for Microbicides (IPM), a nonprofit headquartered in Silver Spring, Maryland, led the study Ring. IPM has also developed the ring and allowed Dapivirine Sciences Janssen Ireland UC.
"I think it is a bold step in the right direction, and it gives the field a thing to build on," said Robin Shattock, studying mucosal immunology and HIV transmission Imperial College London and chairs the scientific board of IPM. "Scientifically, there is much that can be done to improve it and make it better."
Preliminary data suggest the ring offered less protection for young women because many do not wear for all 28 days between study visits. Dapivirine levels that descend each day that the rings used were higher in some rings used than others. Greater protection took place when there was less left Dapivirine. "It is a little a while 'duh'," said epidemiologist Zeda Rosenberg, CEO of IPM. "Everything will work if it is used."
obstinate adherence problems have other pre-exposure prophylaxis, or PrEP, strategies to prevent infection with HIV, most of which require taking anti-HIV pill every day. But researchers had hoped that a ring that can be inserted once a month and left alone would circumvent this problem. Based on samples of blood monthly, Hillier said they initially thought they were right. But they may have been misled by the trial participants who reintegrated rings before study visits to please the researchers. "We call this effect" white coat "," Hillier said, explaining that if women inserted the ring the day before the test, they would have ample drugs in their blood.
Biological factors could also help to explain the lower effectiveness in younger women. "the differences in the genital tract can make them more susceptible to infection," said Shattock. Another possibility is that they had more sex with partners infected with HIV. But ASPIRE, the rate of new infections among women who received rings containing placebo was 5.4% per year in the 21 and under a similar group in the incidence of 6.1% per year in the slice age 22 to 26.
in the future, the researchers hope to test higher levels of antiretroviral drugs or more powerful-in vaginal rings. IPM provides a ring to which secretes the drug for 3 months. And researchers think that many women find most attractive product if it combines the anti-HIV drugs with hormonal contraceptive, which are already sold worldwide in vaginal rings.
Whatever the shortcomings of the ring Dapivirine 28 days tested both studies, IPM plans to seek regulatory approval in about 1 year. Rosenberg provides that each ring initially will sell for about $ 5.
0 Komentar