Africa Analysis: Getting combination tools to fight HIV – SciDev.Net

Regulatory challenges could delay new, game-changing tools for fighting HIV/AIDS in women, writes Linda Nordling.
 
One of the most challenging aspects of fighting Sub-Saharan Africa’s devastating HIV epidemic has been finding ways for women — who are most at risk of catching the virus — to protect themselves.
 
Traditional prevention methods such as condoms or faithfulness to one partner are often outside women’s control. Sex workers, who have a very high risk of HIV infection, usually get paid more for sex without condoms. As for faithfulness, there is little a woman can do to stop her partner from cheating.
 
Recent years have seen advances in the development of biomedical HIV prevention technologies. By combining these technologies with contraceptive tools, scientists are now working on multipurpose prevention tools that could make a big difference to African women facing HIV risk.

“Traditional prevention methods such as condoms or faithfulness to one partner are often outside women’s control.”

Linda Nordling

 
But securing regulatory approval for combination interventions, especially those that involve technologies that are currently experimental, will be time-consuming. For some African women, it could prove a deadly wait.
 
Next generation HIV tools
 
An impressive pipeline of next generation HIV prevention methods were on display at the HIV Research for Prevention (R4P) conference held in Cape Town, South Africa, from 28 to 31 October.
 
The conference focussed on only HIV prevention, and was attended by over 1,300 delegates from all over the world. Encouragingly, nearly 500 delegates were from Africa, and approximately 30 per cent of the research studies accepted for presentation came from African institutions and investigators.
 
Exciting HIV prevention methods include the antiretroviral pill Truvada, which, when taken daily, has been shown to reduce the infection risk of people at high risk of getting HIV — such as HIV negative people whose partners are HIV positive, or intravenous drug users — by over 90 per cent.
 
Microbicide gels that are inserted into the vagina or rectum have been partially effective in reducing sexual transmission of HIV. The first partially successful vaginal microbicide gel containing the drug tenofovir was shown to protect 39 per cent of women from HIV in a 2010 South African study. [1] More gels have since gone through efficacy testing, but adherence to such products is not always good, as the gel needs to be inserted before and after each sexual encounter.
 
Other delivery methods could prove user-friendlier. Vaginal silicon hoops that contain slow-releasing antiretrovirals are currently undergoing efficacy testing in African women. They would only have to be inserted once a month. Scientists also hope that research on long-term injectable antiretrovirals for treatment of HIV/AIDS could pave the way for injectable or implantable HIV prevention tools.
 
Contraceptive combos
 
None of the technologies mentioned above, apart from the pre-exposure Truvada treatment, is yet licensed for clinical use. However, scientists are already talking about creating multi-purpose HIV prevention and birth control tools, which could prove particularly useful for African women.
 
Multipurpose prevention technologies, or MTPs, are a rapidly growing field covering tools that simultaneously prevent unintended pregnancy, HIV, and other sexually transmitted infections.
 
A study funded by the Bill & Melinda Gates Foundation in Uganda, Nigeria and South Africa, published last month, found that 93 per cent of the women interviewed said they would prefer combined contraception and HIV prevention technologies over a product that offered either one or the other. [2]   
 
A simple example of MPT would be to use a vaginal microbicide with SILCS, an easy-to-use diaphragm developed by PATH, a non-profit medical health technologies company.
 
Other MPTs could include vaginal rings that release contraceptive hormones as well as HIV-fighting antiretrovirals. Contraceptive rings have been around for more than a decade and are changed monthly, same as the rings containing the anti-HIV drug dapivirine undergoing in clinical trials. The non-profit reproductive health organisation CONRAD launched a safety study in 50 healthy women of a vaginal ring combining contraception, HIV and herpes prevention on 16 November.[3] 
However, it is with the injectable and long-term antiretroviral prevention ideas that arguably hold the greatest promise for African women in low-resource settings. Currently, long-term injectable contraceptives and contraceptive implants are hugely popular among South African women.
 
Such acceptance of a new technology from its end users can make or break its success in the real world, Gita Ramjee, a South African clinical researcher based in Durban, said on the sidelines of the R4P conference in Cape Town.
 
South African women’s acceptance of injectable and implantable birth control is a good indicator that they would welcome and make use of long-acting HIV prevention technologies, she said. However, she added that there will be no prevention option that will fit all women. Rather, scientists like her should study a range of technologies so that women can choose what they prefer.
 
Regulatory challenges
 
However, multipurpose prevention tools could prove slow to clear the stringent regulatory hoops needed before being allowed for widespread clinical use.
 
First, any experimental treatments have to be proven safe and effective on their own. Then, tests have to ascertain that two treatments being combined won’t interfere with each other, or provide harmful unintended consequences.
 

“Multipurpose prevention technologies, or MTPs, are a rapidly growing field covering tools that simultaneously prevent unintended pregnancy, HIV, and other sexually transmitted infections.”

Linda Nordling

The successful delivery of MPTs to the market will also require cross-disciplinary collaboration between scientists working on HIV, birth control and other sexually transmitted infections. Funders and advocacy groups working in these fields also need to come together to make MPTs a reality.
 
However, it’s likely to take time, and those months and years will cost some African women dearly.
 
How quickly these interventions can be developed depend on how well these many actors can work together towards a common goal. They should try their best. Africa’s women deserve no less.

This article has been produced by SciDev.Net’s Sub-Saharan Africa desk.