Africa Clinical Research Network awarded grant to lead SUPPRESS-LA, a Phase 3 trial
evaluating long-acting antiretroviral therapy to prevent mother-to-child HIV transmission
Africa-led, multicountry study in South Africa, Uganda and Zimbabwe will evaluate whether
long-acting injectable antiretroviral therapy can sustain maternal viral suppression and close the
residual gap that continues to drive paediatric HIV in Eastern and Southern Africa
HARARE, ZIMBABWE — 18 August 2026 — The Africa Clinical Research Network (ACRN) today
announced that it has been awarded a grant from the Gates Foundation to sponsor the
Supporting Programmatic Maternal Viral Suppression with Long-Acting therapy study
(SUPPRESS-LA), a Phase 3 multicountry clinical trial evaluating whether a long-acting injectable
antiretroviral regimen can sustain maternal viral suppression throughout pregnancy and
breastfeeding, thereby reducing residual mother-to-child HIV transmission.
The remaining challenge in preventing mother-to-child HIV transmission across Eastern and
Southern Africa
Eastern and Southern Africa continues to carry the overwhelming majority of new paediatric HIV
infections worldwide. Approximately 120,000 children under five years acquired HIV globally in
2024, with most infections occurring in this region. Despite more than two decades of progress in
prevention of mother-to-child transmission (PMTCT), transmission rates in the three SUPPRESS-LA
countries remain above the World Health Organization (WHO) and the Joint United Nations
Programme on HIV/AIDS (UNAIDS) elimination threshold of less than 5% among breastfeeding
populations:
- South Africa has the largest population of pregnant women living with HIV in the world and
recorded an estimated 6,600 new paediatric HIV infections in 2024 — the second-highest
national total globally. Approximately 53% of these transmissions occurred during the
breastfeeding period. - Zimbabwe has reduced its mother-to-child transmission (MTCT) rate from over 20% in the
early 2000s to 6.4% in 2024, but the country remains above the 5% elimination threshold.
UNAIDS Spectrum modelling estimates that approximately 40% of remaining mother-to-child
HIV transmission in Zimbabwe occur postnatally, during breastfeeding. - Uganda has made comparable progress, but final-mile mother-to-child HIV transmission,
measured through the end of the breastfeeding period, is still estimated at approximately 6%,
and mother-to-child HIV transmission remains the principal source of new HIV infections in
children in the country.
The common driver across all three settings is the difficulty of sustaining viral suppression on
daily oral therapy through pregnancy, the period after childbirth (postpartum) and
breastfeeding. A 2026 systematic review and meta-analysis of pregnant and lactating women
on antiretroviral therapy across Africa reported an overall rate of successful viral suppression of
approximately 81% — well below the UNAIDS 95% target. Prospective cohort data from Cape Town
demonstrate that the high antenatal viral suppression rates achieved on
tenofovir-lamivudine-dolutegravir (TLD) decline substantially in the postpartum period,
identifying daily-adherence failure rather than regimen failure as the principal driver of residual
mother-to-child HIV transmission.
SUPPRESS-LA will evaluate whether eliminating the need for daily oral dosing entirely — through
long-acting injectable therapy administered every eight weeks and every six months — can
sustain maternal viral suppression across pregnancy, postpartum and breastfeeding, and
ultimately reduce residual mother-to-child HIV transmission.
A trial designed for, and led from, Africa
“Mother-to-child HIV transmission is one of the most consequential challenges in global health,
and yet our daily-dosing regimens are not reaching the women who most need them,
particularly through the postpartum and breastfeeding period,” said Dr. Tariro Makadzange, Chief
Executive Officer of ACRN. “SUPPRESS-LA addresses a question of direct importance to African
mothers and infants, in the settings where the evidence is most needed and where the findings
are intended to inform practice, with African investigators leading the research. We are grateful
to the Gates Foundation for supporting African-led research that addresses priorities identified
by African clinicians, researchers and communities.”
SUPPRESS-LA will be conducted across clinical research sites in South Africa, Uganda and
Zimbabwe, with country Principal Investigators leading implementation through nationally
recognized African research institutions. Regulatory submissions are being coordinated through
the African Vaccine Regulatory Forum (AVAREF) joint review mechanism, enabling harmonized
review by the South African Health Products Regulatory Authority (SAHPRA), the Medicines Control
Authority of Zimbabwe (MCAZ) and the Uganda National Drug Authority (NDA). The first
participant is expected to be enrolled in early 2027.
About ACRN
The Africa Clinical Research Network is an African-led clinical research platform built to
strengthen and expand the capacity for high-quality clinical trials on the continent. ACRN
combines a hybrid site management organisation with selected clinical research organisation
services, supporting a preferred provider network of clinical research sites across 14 African
countries. The platform invests in regulatory, laboratory, data management and clinical
operations infrastructure, while strengthening the capacity of African investigators and trial staff,
and building a pipeline of studies across key therapeutic areas. ACRN’s mission is to ensure that
the science informing healthcare in Africa is generated, led and owned in Africa.
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