By Lenah Bosibori
New research led by Kenyan scientists is offering important evidence on how to manage HIV treatment failure, protect pregnant and breastfeeding women, and simplify treatment for older people living with HIV.
The findings were presented at the 26th International AIDS Conference held in Australia and come as HIV programmes across Africa face new questions about drug resistance, long-term treatment and the needs of people who have often been underrepresented in research.
The studies were led by the Centre for Epidemiological Modelling and Analysis (CEMA) at the University of Nairobi. Researchers said the evidence could help inform HIV treatment policies in Kenya and other African countries.
“HIV treatment has transformed millions of lives,” said Dr Loice Ombajo, Principal Investigator and CEMA Co-Director. “The results we presented showcase African-led research generating evidence to improve HIV treatment policies for populations often underrepresented in global research, including older adults and people experiencing treatment failure, including pregnant and breastfeeding women.”
The research focused on two studies. The Ndovu Study is examining what should happen when people taking dolutegravir-based HIV treatment experience treatment failure. The Sungura Study is assessing whether an easier two-drug HIV treatment regimen is safe for older adults who have previously been exposed to hepatitis B.
When HIV treatment stops working
Dolutegravir, often referred to as DTG, is widely used in HIV treatment because it is effective, generally well tolerated, and has historically had a high barrier to drug resistance.
However, as more people in sub-Saharan Africa use DTG-based treatment, doctors are increasingly identifying cases where the virus develops resistance to the medicine.
“While resistance to dolutegravir has historically been considered rare, increasing use of DTG based antiretroviral therapy across sub Saharan Africa has led to increasing recognition of emerging drug resistance,” Dr Ombajo said.
The Ndovu Study is a multicountry prospective study taking place in Kenya, Tanzania, Mozambique and Lesotho. It is examining the best treatment approach for people whose HIV is no longer adequately controlled while they are taking DTG-based treatment.
The study is also looking at patterns of drug resistance linked to dolutegravir.
In Kenya, researchers tested the first 2,994 participants enrolled across 131 health facilities. All participants had been taking DTG-based HIV treatment for at least six months.
Those found to have major drug resistance mutations associated with dolutegravir were enrolled in a clinical trial within the wider study.
Between September 1, 2025 and April 2, 2026, 72 participants were randomly assigned to one of two treatment groups. Thirty-eight participants continued receiving the standard dose of dolutegravir, while 34 participants were switched to a treatment regimen containing ritonavir boosted darunavir, known as DRV/r.
Early findings showed better viral suppression among participants who were switched to the DRV/r regimen.
After one month, 80 percent of participants in the DRV/r group, or 24 out of 30 people with available results, recorded a drop in viral load. This compared with 19 percent, or seven out of 37, in the DTG group.
By the third month, 83 percent of participants in the DRV/r group, or 20 out of 24, had achieved viral suppression. In comparison, 13 percent of those who remained on DTG, or three out of 23, had achieved viral suppression.
Viral suppression means reducing the amount of HIV in a person’s blood to very low levels. It is important for protecting a person’s health and preventing transmission of the virus.
“There is currently limited evidence to guide the management of dolutegravir resistance among people living with HIV,” Dr Ombajo said. “Through the Ndovu Study, we are generating much needed evidence to inform treatment decisions for patients who develop DTG resistance.”
She said the findings reinforce the need for accessible tools that can detect DTG resistance and support timely treatment decisions, particularly in settings where drug resistance testing is not widely available.
The preliminary results suggest that people with major DTG associated resistance mutations may face a higher risk of treatment failure if they remain on standard dose DTG. The findings indicate that switching to a DRV/r based regimen may offer better viral suppression for this group.
Following an early review of the interim findings on April 8, 2026, the Independent Data Safety and Monitoring Board recommended stopping further randomisation to the DTG treatment group because of the difference in outcomes between the two groups.
The study is continuing to generate evidence on treatment options for people with drug-resistant HIV.
A critical concern for pregnant and breastfeeding women
The Ndovu Study also examined pregnant and breastfeeding women with persistent viraemia while receiving DTG based treatment.
Viraemia means that HIV remains present in the bloodstream at levels high enough to raise concern. During pregnancy and breastfeeding, uncontrolled HIV can increase the risk of mother to child transmission.
Infant infections account for about 10 percent of new HIV infections globally. Poor adherence to HIV treatment and resulting high viral load during pregnancy or breastfeeding are among the leading contributors to these infections.
Researchers examined 109 pregnant and breastfeeding women with persistent viraemia. Most were aged 25 years or older, had been on HIV treatment for more than one year and had a viral load above 10,000 copies per millilitre.
The study found that enhanced adherence support helped more than half of the women achieve viral suppression within three months while remaining on the same treatment.
The findings point to the importance of timely viral load testing and targeted adherence counselling for pregnant and breastfeeding women.
For health programmes, the message is that a high viral load does not always mean that a mother must immediately change treatment. Some women may first need support to take their medicines consistently, understand treatment instructions and address barriers that make adherence difficult.
But researchers say such support must be provided quickly, especially during pregnancy and breastfeeding, when delays can put both mother and child at risk.
Can HIV treatment be simplified for older adults?
Another study presented at the conference examined whether an easier two drug HIV treatment regimen is safe for older adults who have previously been exposed to hepatitis B.
The Sungura Study followed 197 adults aged 60 years and above in Kenya. Participants switched from a three drug regimen containing bictegravir, emtricitabine and tenofovir alafenamide to a two drug combination of dolutegravir and lamivudine.
The change matters because tenofovir also helps protect against hepatitis B. Researchers wanted to determine whether removing tenofovir could cause hepatitis B to return in people who had previously been exposed to the virus.
After 72 weeks, the findings were reassuring.
Among 92 participants who had previously been exposed to hepatitis B, 98 percent showed no signs of active hepatitis B infection. None experienced a return of the virus or developed a new hepatitis B infection during the study period.
The findings suggest that the simpler two drug HIV treatment regimen may be a safe option for older adults with previous exposure to hepatitis B.
The study also highlights the importance of increasing hepatitis B vaccination, which can prevent new infections and help protect people living with HIV from complications linked to the virus.
Older people living with HIV are an increasingly important group in HIV care. As treatment improves and people live longer, health systems must respond to the health needs that come with ageing, including other chronic illnesses, long-term medicine use and the risk of drug interactions.
African evidence for African health systems
Dr Ombajo was also invited to present the Ndovu Study findings at a World Health Organization pre-conference Think Tank on HIV treatment.
CEMA said the emerging evidence contributed to discussions on possible updates to global guidance for people living with HIV who experience treatment failure while taking DTG based treatment.
The researchers say studies conducted within African health systems are especially important because treatment decisions should reflect the realities faced by patients and healthcare workers in the region.
These include limited access to resistance testing, differences in healthcare infrastructure, treatment availability and the needs of communities affected most by HIV.
“By conducting large multi-country clinical studies and collaborating closely with ministries of health, healthcare workers and research institutions, CEMA is helping to ensure that decisions about HIV treatment are informed by evidence generated within the populations most affected by the epidemic,” Dr Ombajo said.
The studies involved collaborations between the University of Nairobi’s Department of Clinical Medicine and Therapeutics, Kenya’s Ministry of Health through the National AIDS and STI Control Programme, SolidarMed in Lesotho, Mozambique’s Instituto Nacional de Saúde, and Muhimbili University of Health and Allied Sciences in Tanzania.
Healthcare facilities, county health teams and local leaders in Kenya also supported the research.
The Sungura Study was supported by ViiV Healthcare, while the Ndovu Study was supported by the Gates Foundation.
As HIV treatment continues to evolve, the studies show that better care will depend not only on new medicines but also on evidence that reflects the experiences of people living with HIV in African countries.
For patients experiencing treatment failure, pregnant and breastfeeding women, and older adults living with HIV, the research offers the possibility of treatment decisions that are more timely, safer and better suited to their needs.