IMPALA Study finds two-monthly injectable HIV treatment safe and preferred by African patients

KENYA— A recent study conducted across Kenya, Uganda, and South Africa has revealed that the injectable HIV treatment Cabotegravir/Rilpivirine (CAB LA + RPV LA), given every two months, is safe, well-tolerated, and preferred by most patients.

These findings bring fresh hope for better treatment adherence, fewer deaths related to HIV, and an improved quality of life for those living with the virus.

The research comes from the IMPALA study, a 24-month randomized controlled trial conducted in collaboration with the Medical Research Council and the Uganda Virus Research Institute, which coordinated the project.

Sponsored by the London School of Hygiene & Tropical Medicine and funded by the Janssen Pharmaceutical Companies of Johnson & Johnson, the study evaluated patient responses to this long-acting injectable regimen.

Dr. Loice Ombajo, an infectious disease expert and co-director at the University of Nairobi’s Center for Epidemiological Modelling and Analysis, served as the principal investigator in Kenya.

She emphasized the importance of these results, explaining that many HIV patients in Africa face challenges, such as taking multiple drugs daily, dealing with stigma, and enduring side effects.

These challenges often lead to difficulties in sticking to treatment, which can cause drug resistance and treatment failure.

By reducing the need for daily pills, injectable therapy offers a promising solution that makes adherence easier and enhances patients’ lives.

Although there have been significant advances in HIV treatment, the global response remains at a crucial point.

In 2024, the World Health Organization estimated that 40.8 million people worldwide were living with HIV, 1.3 million people had contracted the virus, and 630,000 died from HIV-related illnesses.

The current standard treatment involves a daily pill combining three or four medicines that suppress the virus.

This often includes Dolutegravir (DTG), a drug recommended since 2016 for its lower side effects and high resistance barrier.

Despite its effectiveness, taking a daily pill remains challenging—especially for adolescents, young adults, and marginalized populations.

These adherence difficulties lead to increased hospitalizations and higher healthcare costs, contributing to hundreds of thousands of HIV-related deaths annually.

The Joint United Nations Programme on HIV/AIDS (UNAIDS) has set ambitious goals to achieve by 2030, known as the 95-95-95 targets: 95% of people living with HIV diagnosed, 95% of those diagnosed on treatment, and 95% of those on treatment virally suppressed.

However, by the end of 2021, only 71% had reached all three targets, showing a significant gap.

Researchers have therefore been investigating simpler, more flexible treatment options. Long-acting injectable HIV therapy has emerged as a leading candidate.

The IMPALA study specifically targeted adults with unsuppressed viral loads for at least 2 years despite prior antiretroviral therapy, suggesting adherence difficulties.

Results showed that the injectable regimen performed just as well as the daily oral dolutegravir-based therapy (TLD) but helped reduce the burden of daily medication.

Dr. Ombajo noted that these results illustrate the transformative potential of long-acting injectables, which could speed progress toward global HIV targets and improve patient outcomes.

She also highlighted the relevance to the World AIDS Day 2025 theme, “Overcoming Disruption, Transforming the AIDS Response,” calling for solidarity and commitment to innovation in combating HIV.