ViiV Healthcare announced the HIV Prevention Trials Network (HPTN) 083 study will be stopped early following an interim analysis showing long-acting, injectable cabotegravir (CAB LA) administered every two months is 69% more effective than the current standard of care, daily oral tablets, in preventing HIV transmission.
The double blind phase IIb/III HPTN 083 study was designed to evaluate the safety and efficacy of long-acting injectable cabotegravir for HIV prevention administered every eight weeks compared to daily oral emtricitabine/tenofovir disoproxil fumarate 200 mg and 300 mg (FTC/TDF) tablets. Each subject was to receive a maximum of three years of blinded study medication. The study opened to enrolment in November 2016. HPTN 083 was conducted in approximately 4,600 men who have sex with men and transgender women who have sex with men at research centers in Argentina, Brazil, Peru, United States, South Africa, Thailand and Vietnam. Cabotegravir was found to be 69% more effective when compared to the current standard of care, thus achieving the primary objective of non-inferiority with the difference approaching superiority in favor of cabotegravir, pending final analysis.
Following review of these findings, the DSMB recommended the blinded, randomized portion of the study be stopped early and results released. Participants who were in the FTC/TDF arm will be offered CAB LA and participants in the CAB LA arm will continue to receive it.
The HPTN is also conducting the phase III HPTN 084 study to evaluate long-acting injectable cabotegravir for HIV prevention administered every eight weeks compared to daily oral FTC/TDF tablets (200 mg/300 mg) in 3,200 women who are at increased risk of HIV acquisition. HPTN 084 opened to enrolment in November 2017 and is being conducted at research centers in Botswana, Kenya, Malawi, South Africa, Eswatini, Uganda and Zimbabwe.
Cabotegravir, an analog of dolutegravir, is an HIV-1 integrase strand transfer inhibitor (INSTI). Cabotegravir prevents viral DNA integration into the host genome and inhibits HIV replication.