Preventing mother-to-child transmission of HIV in late pregnancy.
In sub-Saharan Africa more than one in five HIV-infected pregnant women are diagnosed in late pregnancy each year. This group is the most likely to transmit HIV to their infants due to delayed initiation of combination antiretroviral therapy (cART). The risk of mother-to-child transmission is directly related to maternal HIV viral load, therefore HIV drugs that quickly decrease viral load may be effective at preventing transmission, even in late pregnancy.
First-line efavirenz-based therapy does not work quickly enough to give these women the best chances of protecting their infant from HIV infection during delivery, the time of greatest risk.
Medications that rapidly decrease viral load could play an important role in the global goal to eliminate mother-to-child transmission of HIV. The project, implemented in South Africa and Uganda, aims to establish high-quality evidence and operational guidance for the use of dolutegravir (DTG) in late pregnancy. It involves a multi-centre trial of 250 HIV-infected women starting combination antiretroviral therapy in late pregnancy.
“Mother-to-child transmission of HIV is preventable, and we have a duty to ensure the burden of HIV is not handed down across generations. More than 100,000 babies acquired HIV last year worldwide. We have both a moral imperative to make new treatments available and affordable, and an ethical imperative to ensure these treatments are supported by robust evidence for safety and efficacy. As this evidence is gathered, we will work closely with international agencies involved in enlarging access and developing clinical guidelines in order to ensure that this research translates into real benefit for such a vulnerable population.”
Professor Saye Khoo, Trial Principal Investigator
Progress so far
The DolPHIN2 pregnancy trial started enrolling participants in January 2018 and reached target recruitment in August 2018. The participants were women initiating antiretroviral therapy in late pregnancy (28–40+ weeks) in South Africa and Uganda. Initial results, presented at the 2019 Conference on Retroviruses and Opportunistic Infections, showed that 74 percent of women receiving DTG achieved viral suppression when giving birth, versus 43 percent in those receiving efavirenz. Final results are expected in early 2021.
In parallel, a qualitative research study aims to identify barriers to the implementation of DTG for use in late-presenting pregnant women. The project is on track to meet targets with initial results expected in mid-2019.
The impact we are seeking
The goal of the grant is to generate evidence to support the use of a DTG-based regimen in pregnant women.This would reduce the rate of mother-to-child HIV transmission in late-presenting HIV-positive pregnant women. An effective DTG-based regimen could reduce the number of children who acquire the virus – currently estimated at 150,000 per year – and generate significant financial savings from averted treatment costs.