http://allafrica.com/stories/200809200019.html

A drug designed to reduce the transmission of HIV when taken as a single pill before unprotected sex is going to be tested in Uganda soon.

The pill has proved successful in monkeys and initial tests in human beings have shown encouraging results, according to Dr Patrick Ndase, who is coordinating the drug trial. A team of Ugandan and American scientists are preparing for a Phase III trial, which is considered the final test before the drug goes into use.

The pill would help discordant couples, where one person is HIV positive and the other is negative, to produce children without spreading the infection. It would also help a woman to protect herself in case her sexual partner does not want to use a condom.

Ndase says they are enrolling volunteers in Kampala, Kabwohe (Bushenyi), Mbale and Tororo. "Overall, we want to enroll 3,900 discordant couples on a volunteer basis and follow them up for a planned period of four years," Ndase said. "Those who want to take part in the trial should go for HIV testing as a couple and if they are discordant, go to our centres for more information," he said.

Such a strategy, in which someone takes a drug to pre-empt infection is referred to as pre-exposure prophylaxis. It has been used against malaria and TB. If the trial is successful, it would be the first time the method is used to prevent HIV among adults.

The trial, funded by the Bill and Melinda Gates Foundation, is a partnership involving universities, Government departments and NGOs in Uganda and the United States. It involves the Makerere University Infectious Diseases Institute, Makerere-University Johns Hopkins University collaboration, the University of Washington, the Centers for Disease Control and Prevention (CDC) and the National Institute of Health of the US. Others participating in the experiment are Kabwohe Clinical Research Centre, TASO Mbale and CDC Tororo.

According to documents from the AIDS Vaccine Advocacy Coalition (AVAC), drugs under study are tenofovir disoproxil fumerate (TDF), commercially known as Viread, and TDF combined with emtricitabine (FTC), commercially known as Truvada. "Both drugs are ARVs that have been in use for treating HIV infection," said the AVC document. "They have proved safe, remain in the blood stream for long periods of time, require once-daily dosing and if someone developed resistance, they would still be able to use many other classes of ARVs".

Ndase added that the two drugs are broad antiviral drugs which can be used for all HIV types. "As ARVs, they are effective both at early and late stage of the infection and as a prevention tool, they can block initial infection. They have no food or drug restrictions and will soon be very affordable because their patent period is ending soon."

Patent period is the time given to a pharmaceutical company that develops a drug to exclusively manufacture and sell it to recover the money invested. After that time, it can allow other companies to manufacture the drug, thereby lowering prices.

Although the drugs are proven to be friendly to the kidneys, liver and bones, Ndase said, volunteers will still be closely monitored to ascertain that they do not suffer side effects.

AVAC, a non profit organisation carrying out global advocacy to expand HIV prevention, revealed that the trials are currently planned or going on in many countries of Africa, Asia, Latin America and the US. "At this point, no one knows whether it will work," a statement says. "But if it does, it will be used in combination with current HIV prevention methods, including safer sex practices, condoms, treatment of sexually transmitted diseases, risk reduction counselling, safe needles, and male circumcision."

Dr. Kuhuumuro Apuuli, Director General of the Uganda AIDS Commission, hails the trials saying all experiments, successful or not, yield important lessons. "Apart from the new scientific information to base our subsequent research on, there is community participation, political involvement and the whole trial site benefits."

He calls for support for the trials and speedy utilisation of the findings. "In Uganda, we have always been champions in the HIV fight. The first HIV vaccine trial in Africa was here. We must remain at the forefront."

He, however, warns that the drug should be taken within the context of a comprehensive prevention strategy against HIV. "At the HIV International Conference in Mexico, it came out clearly that we need to combine all prevention measures, which include behaviour change, condoms, treatment, prevention of mother-to-child transmission, male circumcision, vaccines and microbicides."

Dr. Elioda Tumwesigye, chairman of the parliamentary committee on HIV/AIDS, welcomes it as good news. "We have 57% discordant couples in Uganda," he says. "There are also young adults who were born with HIV and want to raise families. Our serosurvey also showed that HIV incidence is high among married people. I think husbands fear to move with condoms and end up in problems. This drug would be the best preventive method which a female can control without permission from a man." Early next year, another trial will start in Kampala and other places in South Africa, using the same drugs in high risk women. The trial to be conducted by Makerere University and Johns Hopkins University corroboration, will be funded by the US National Institute of health. It will target 4,200 sexually active women.