DURHAM, N.C. - Study results released today by the HIV Prevention Trials Network (HPTN) show long-acting injectable cabotegravir (CAB LA) to be well tolerated by men and women and support the dosing schedule currently being used in a phase 3 HPTN study for HIV prevention. Analysis of HPTN 077 study data presented today at the 9th IAS Conference on HIV Science in Paris, France, supported further development of CAB LA for HIV prevention in men and women using 600mg (3 mL) injections every eight weeks with the first two injections given four weeks apart.
"Having more options for HIV prevention is critical, especially those that need not be used on a daily basis," said HPTN 077 protocol chair Raphael J. Landovitz, M.D., M.Sc. "The next step is to evaluate in larger studies whether the dose of CAB identified will work to prevent HIV infection." Dr. Landovitz is an associate professor of medicine in the Division of Infectious Diseases at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA) and associate director of the UCLA Center for Clinical AIDS Research & Education (CARE).
The HPTN 077 study tested the safety, tolerability, acceptability, and pharmacokinetics of the long-acting injectable integrase inhibitor cabotegravir. The study enrolled 199 men and women at low risk for getting HIV at sites in Brazil, United States, Malawi, and South Africa. Study participants received cabotegravir or a matching placebo first as pills to make sure that they could tolerate it, and then as injections: either 800 mg (2mL in 2 injections) every 12 weeks for a total of three doses, or 600 mg (3mL as a single injection) every 8 weeks after a 4-week "loading dose" for a total of 5 doses. The primary analysis was performed at 41 weeks after enrollment into the study in both groups. The 600 mg dose every 8 weeks consistently showed appropriate levels in the blood stream in both men and women, and was well tolerated. The study will continue with follow-up until July 2018.
"Knowing that a drug is well tolerated and finding the correct dose to use are key steps in the development of new HIV prevention methods," said Myron Cohen, M.D., co-principal investigator for the HPTN and director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill. "If injectable cabotegravir is shown to protect against HIV transmission in HPTN 083 and 084, people at risk of becoming HIV infected will have another option that they can use."
The HPTN is currently conducting HPTN 083, the first efficacy study of CAB LA for pre-exposure prophylaxis (PrEP) among at-risk cisgender men and transgender women who have sex with men in the U.S., Argentina, Brazil, Peru, South Africa, Thailand, and Vietnam.
Additionally, HPTN 084 is being developed to test the efficacy of CAB LA among at-risk women in sub-Saharan Africa
The HPTN 077 study is sponsored by the U.S. National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Study drugs were provided by ViiV Healthcare. For more information about HPTN 077, visit hptn.org, or ClinicalTrials.gov using study identifier NCT02178800.
About HPTN: The HIV Prevention Trials Network (HPTN) is a worldwide collaborative clinical trials network that brings together investigators, ethicists, community and other partners to develop and test the safety and efficacy of interventions designed to prevent the acquisition and transmission of HIV. HPTN studies evaluate new HIV prevention interventions and strategies in populations and geographical regions that bear a disproportionate burden of infection. The HPTN research agenda is focused primarily on the use of integrated strategies: use of antiretroviral drugs (antiretroviral therapy and pre-exposure prophylaxis); interventions for substance abuse, particularly injection drug use; behavioral risk reduction interventions and structural interventions. NIH funds HPTN. For more information, visit hptn.org.