Partners launch phase 2 safety study of a long-acting injectable to prevent HIV

Contact:
Elena Pantjushenko, 650.392.2537, epantjushenko@path.org.

South San Francisco, United States, February 18, 2015–PATH, in collaboration with the US National Institutes of Health (NIH) and the HIV Prevention Trials Network (HPTN), has launched a new study to test the safety and acceptability of a long-acting injectable formulation of the proven antiretroviral drug rilpivirine (TMC278) as a pre-exposure prophylaxis (PrEP) against HIV.

The trial–HPTN 076–will be implemented by the NIH-funded HPTN, with PATH providing regulatory sponsorship.

PrEP involves using antiretroviral drug-based interventions to reduce the risk of HIV infection in healthy adults, with current strategies including oral or topical PrEP modalities. While oral PrEP with tenofovir disoproxil fumarate and emtricitabine (Truvada) demonstrated high levels of efficacy and has been approved by the US Food and Drug Administration for prevention of HIV, some studies have shown that low adherence to oral and topical regimens, especially among women, may limit its effectiveness.

A long-acting (LA) formulation of PrEP requiring less frequent dosing has the potential to improve uptake and adherence. It could also expand the global toolbox of prevention interventions, providing safe and effective choices to address different circumstances and preferences. Such drugs would complement other HIV prevention strategies including an eventual vaccine, microbicides, barrier contraception, voluntary medical male circumcision, treatment as prevention, and other options.

"We are very pleased to join our partners as we begin further evaluation of this promising candidate, rilpivirine (TMC278) LA, as a PrEP agent," said Dr. David Shoultz, PATH's Drug Development program leader. "Long-acting injectable antiretrovirals hold great potential to protect and empower people who are most vulnerable to HIV, particularly women and young girls in countries with high HIV prevalence. These drugs could add an important new option to a current package of effective interventions, positioning us for even greater success in battling the virus."

HPTN 076 is expected to enroll approximately 132 healthy, HIV-uninfected women who are sexually active and at low risk for infection at four sites in South Africa, the US, and Zimbabwe. The researchers will compare the safety and acceptability of intramuscular injections of rilpivirine LA to placebo injections given once every 8 weeks over a 10-month period, with an 8-month follow-up. Study participants will be counseled at each clinic visit on how to protect against HIV infection.

"With women bearing the brunt of the HIV burden in Southern Africa and evidence of increasing infection in some women in the US, it is particularly timely to embark on testing the safety and acceptability of this long-acting antiretroviral agent as a prophylactic intervention in women in Southern Africa and the US," said Dr. Linda-Gail Bekker, HPTN 076 study protocol chair and lead investigator at the Cape Town, South Africa research site.

Other partners include the pharmaceutical company Janssen Sciences Ireland UC, which granted to PATH a royalty-free license for the development of rilpivirine LA in 2013. Funding to PATH to establish the viability of an injectable form of PrEP as an intervention for HIV prevention is being provided by the Bill & Melinda Gates Foundation.

For more information about the HPTN 076 study, see Clinicaltrials.gov using the identifier NCT02165202.

PATH's Drug Development program works to develop and ensure the availability and accessibility of safe and effective new medicines for diseases disproportionately affecting people in developing countries. For more information, please visit sites.path.org/drugdevelopment/.