Slow dissolving, longer-acting HIV prevention method in the pipeline

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A dapivirine vaginal ring to be used in an HIV prevention trial. PHOTO | AFP

Kenya is one of four countries chosen for the rollout of a vaginal film, containing the antiretroviral drug dapivirine. It is designed to dissolve over the course of 30 days acting as a HIV prevention method for women.

The vaginal film is being put to the test for the first time in a study launched last week that aims to determine its practicability and acceptability as a potential HIV prevention method for women.

Comparable to breath mint strips that dissolve in the mouth, vaginal films are designed to dissolve after being inserted into the vagina. Previous studies have explored the use of vaginal films as a drug delivery method for HIV prevention, but they have typically involved quick-dissolve films or films that dissolve within a week.

Refining the design

The study, known as Matrix-002, is being conducted by Matrix, a project funded by the United States Agency for International Development (USAid).
In Matrix-002, researchers are evaluating the acceptability, usability, and safety of two prototype monthly vaginal films that do not contain any active drug. This approach allows them to gather insights into potential design refinements, including the shape of the film, before conducting a first-in-human study of the monthly dapivirine film.

The study will enrol 100 women and 30 sexual partners at five sites across Kenya, South Africa, Zimbabwe, and the US.

Teams led by the University of Pittsburgh and Magee-Womens Research Institute in the US are leading the study and developing the monthly dapivirine vaginal film products and a dual-purpose film containing dapivirine and a hormonal contraceptive.

By starting with placebo films that do not contain any active drug, the study aims to answer crucial questions about acceptability of a vaginal film that takes 30 days to dissolve. It also seeks to determine the support and counselling women may need to use the film effectively. The insights gained from this study will shape the design of the final product to increase chances of its success.

Matrix places great importance on incorporating end-user and stakeholder feedback during the early stages of product development, as it evaluates two prototype vaginal films with different shapes based on feedback received during stakeholder consultations. The study will randomly assign participants to use one of the two placebo films.

“From the study of placebo films with no active drug, we will be able to answer fundamentally important questions. Are women, especially African women, comfortable with the idea of using a vaginal film taking 30 days to dissolve? What kind of support and counselling will they need to use it properly?” posed Matrix-002 protocol co-chair and investigator at the Harare Health and Research Consortium Zengeza clinical research site in Zimbabwe, Nyaradzo Mgodi.

The study will be underway at all five clinical research sites early 2024, with follow-up completed by mid-2024.

The results of the study are anticipated by the end of 2024. If successful, the first-in-human study of the monthly dapivirine film could begin in 2025.

“We are fully aware of the urgent need for more HIV prevention methods for women, but we also don’t want to rush into study of a new product with design features that may not be to the liking of women and could therefore impact product use.

Something as simple as the shape of the film, or how it feels to the touch, are important considerations that are best resolved as early in the process as possible,” added protocol co-chair and behavioural scientist from RTI International, Berkeley, Calif., Alexandra.

With women and girls accounting for a significant percentage of new HIV infections in Sub-Saharan Africa, at 63 percent of all new HIV infections in Sub-Saharan Africa in 2022, versus 46 percent globally, there is an urgent need for additional HIV prevention methods.

In much of Africa, daily oral PrEP (pre-exposure prophylaxis), which requires taking an ARV tablet every day, is the only biomedical prevention method available. But daily pill-taking has been especially challenging for adolescent girls and young women according to UNAids. Despite the dapivirine ring and cabotegravir long-acting injectable (CAB-LA) being recommended by WHO and approved in several African countries, neither method is yet widely available. The vaginal film offers a potential alternative that could meet the diverse preferences and needs of women.