New science: Highlights from CROI2019
Last week the Conference for Retroviruses and Opportunistic Infections (CROI) was held in Seattle, USA. Spotlight did not attend this year’s conference, but fortunately all CROI abstracts and presentations are made available online. Below we have picked some highlights of relevance for South Africa.
1. New TB prevention therapy works well with dolutegravir
From July the antiretroviral drug dolutegravir will become part of the standard first line treatment for HIV in the public sector in South Africa. Also, in 2019, it is expected that South Africa will introduce a new standard therapy called 3HP for the prevention of TB. The 3HP regimen involves taking a weekly pill containing the medicines isoniazid and rifapentine for three months.
A study presented at CROI found that it is safe to take dolutegravir-based antiretroviral therapy together with 3HP without adjusting the dosage of either. This is good news for patients, since it means that they will not have to take extra dolutegravir pills as was feared might be the case. The confirmation of safety also means that 3HP is now likely to be included in TB prevention guidelines in South Africa and made available in the public sector – providing a low enough price can be negotiated. You can read HIV I-base’s coverage of the study here.
2 . Using two important new tuberculosis treatments together is safe
Bedaquiline and delamanid are the only new TB medicines to be approved in decades – both for the treatment of drug-resistant forms of TB. Drug-resistant forms of TB are treated with anything from three to eight different medicines – typically around five. Yet, until now it was not known whether it is safe to use these two new drugs together – both impact heart rhythms (so-called QT intervals).
A study presented at CROI found that it is indeed safe to use these two drugs together, providing a baseline heart test is done when treatment is started to rule out pre-existing heart risk. The researchers concluded: “The combined effect on the QTcF interval of co-administration of bedaquiline and delamanid is clinically modest and no more than additive. You can read the full abstract here.
This study will likely contribute to updates in both WHO and South African treatment guidelines for drug-resistant TB.
3. Monthly ARV injections appear to be safe and effective
Two studies presented at CROI explored the use of monthly injections of the two ARVs cabotegravir and rilpivirine for HIV treatment – the one study in people already stable on HIV treatment and the other in patients newly starting treatment. Both studies found the injections to be about as safe and effective as daily pills. For more detail, see HIV I-Base’s write-up of the two studies here.
It now seems likely that, for at least some people, monthly injections will become an alternative treatment option to daily pills in the next few years. The usual issues with price, registration and public sector availability still lie in wait. In addition, whether people will prefer monthly injections to daily pills out in the real world remains to be seen – in these two studies at least patients were very positive about the injections.
4. New HIV prevention therapy seems as good as current standard
The current gold-standard in HIV prevention treatment is the combination of the medicines tenofovir and FTC in pill form. TAF is a new form of tenofovir that allows for smaller pills and appears to have a slightly better safety profile. A study presented at CROI found that TAF plus FTC was as effective as traditional tenofovir plus FTC in preventing HIV infection while appearing to be better for bone density and the health of the kidneys. The study was conducted in gay men and transgender women, but the findings are likely generalisable to other groups. TAF has been licensed to the Medicines Patent Pool, so affordable generics of this new option for HIV prevention are likely not too far away.
5. Integrase inhibitors seem to cause moderate weight gain
Integrase inhibitors, the class of drugs including dolutegravir, appears to be associated with a slight increase risk of weight gain. There are a number of studies looking at this issue and the findings are not conclusive as to what sub-group of people are most at risk and which integrase inhibitors are most strongly linked, but the general finding of an increased risk seems to be well-founded. As pointed out in a summary of the evidence on the website AIDSMap, the weight gain is fortunately not like that associated with lipodystrophy (a side effect of earlier ARVs such as d4T that lead to abnormal fat distribution that many found stigmatising). Either way, the potential for modest weight gain may or may not turn out to be an issue as dolutegravir becomes available in the public sector in South Africa.
6. Massive HIV prevention study confirms importance of community healthcare workers
PopART is possibly the largest HIV prevention study ever conducted. The key PopART intervention included annual home-based HIV testing provided by community healthcare workers who also supported linkage to care, treatment adherence and other related services. The study randomised 21 communities in South Africa and Zambia to one of three interventions: universal treatment plus the PopART intervention, treatment according to local guidelines plus PopART, and a control arm with the standard of care in the country without PopART.
The universal coverage plus PopART arm had a 7% lower incidence rate than the control arm – a finding which was not statistically significant. The local guidelines plus PopART arm however had a statistically significant 30% lower incidence than the control arm. The counter-intuitive finding that incidence was higher in the universal treatment group than the local guidelines group is puzzling. Even so, the underlying indication that community healthcare workers working in the PopART model can help bring down incidence is compelling. AIDSMap reports that it emerged in questions after the session where the findings were presented that the two PopART arms together had 20% lower HIV incidence than the control. To what extent government will implement aggressive PopART-style interventions of course remains an open question.
The researchers concluded their abstract: “Community-based HIV testing and linkage is a key component of combination prevention in efforts to achieve effective HIV control.” You can read the abstract here.
7. Food vouchers increases HIV testing in men in KwaZulu-Natal
Getting more men to test for HIV is one of the biggest challenges in South Africa’s HIV response. A study conducted in KwaZulu-Natal tried three different interventions to encourage men to take up home-based HIV testing in different communities – comparing all three interventions to the current standard of care. In one set of communities men were offered R50 food vouchers as an incentive to test, in another the vouchers were offered together with male-targeted counselling provided through an App, and in the third the counselling was offered without the voucher. While the counselling App did not have much impact, the probability that men would test was increased by about 50% in the communities where vouchers were offered. The researchers concluded that: “Micro-incentives significantly increased the uptake of home-based HIV testing among men in rural South Africa and should thus be considered as a policy option where HIV testing rates are low.” You can read the full abstract here.
8. Second man cured of HIV
Much of the headlines from this year’s CROI were dominated by reports of a second man ‘cured’ of HIV following a stem cell transplant. While these cures are important scientific advances, they are of no immediate relevance to almost all people living with HIV given that it involves an extremely dangerous procedure that one would only risk when faced with the serious risk of death. HIV I-Base has written a good summary of the case here and long-time AIDS activist Gregg Gonsalves did a good job of putting it all in perspective here.