Phase III Mosaico study of Ad26.Mos4.HIV discontinued for HIV patients

The study’s independent Data and Safety Monitoring Board (DSMB) determined that the regimen was not effective in preventing HIV infection compared to placebo among study participants. No safety issues with the vaccine regimen were identified. In light of the DSMB’s determination, the Mosaico clinical trial will be discontinued. Participant notifications and further analyses of the data are underway. Throughout the trial, study investigators have ensured that any individuals who contracted HIV received prompt HIV treatment and care.

The Mosaico DSMB analysis, based on the data available to date, indicated that the regimen does not protect against HIV and the study is not expected to meet its primary endpoint. No safety issues with the vaccine regimen were identified. In light of this, the study will be discontinued, and further analyses are underway. The DSMB’s determination follows the primary analysis of the Phase IIb Imbokodo study, which was announced in August 2021 and found that a similar investigational HIV vaccine regimen did not provide sufficient protection against HIV in a population of young women in sub-Saharan Africa. The investigational vaccine regimen used in the Imbokodo study was found to have a favorable safety profile.