Janssen, Global Partners Discontinue HIV Vaccine Study, Saying Regimen Is Not Effective

Janssen Pharmaceutical Companies of Johnson & Johnson’s investigational HIV vaccine regimen was not effective in preventing HIV infection compared with the placebo, results of the phase 3 Mosaico study (NCT03964415) showed.¹

The study results were evaluated by an independent data and safety monitoring board, which did not identify any safety issues associated with the vaccine.¹

“We are disappointed with this outcome and stand in solidarity with the [individuals] and communities vulnerable to and affected by HIV,” Penny Heaton, MD, global therapeutic area head of vaccines at Janssen Research & Development LLC, said in a statement. “We remain steadfast in our commitment to advancing innovation in HIV, and we hope the data from Mosaico will provide insights for future efforts to develop a safe and effective vaccine.”¹

Because of the determination by the independent review board, the trial will be discontinued. Individual notifications and further analyses of the data are also under way.¹

Investigators have ensured that any individuals who contracted HIV received care and treatment throughout the trial.¹

The phase 3 trial began in 2019 and completed vaccinations in October 2022. It was conducted at more than 50 trial sites, including Argentina, Brazil, Italy, Poland, Spain, and the United States.¹

The trial included approximately 3900 cisgender men and transgender individuals who have sex with cisgender men and/or transgender individuals. Participants represented groups and populations who are vulnerable to contracting HIV.¹

Investigators evaluated the investigational vaccine regimen, containing a mosaic-based adenovirus serotype 26 vector, which was administered during 4 vaccination visits in a 1-year period. A mix of soluble proteins, including aluminum phosphate and Clade C/Mosaic gp140, was also administered at visits 3 and 4.¹

The review board determined that the regimen does not protect against HIV and is not expected to meet its primary endpoint based on the available data.¹

There were no safety issues identified for the vaccine and further analyses will continue even though the study will be discontinued.¹

The decision also follows the primary analysis of the phase 2b Imbokodo study (NCT03060629), which was announced in August 2021. Results showed that a similar investigational HIV vaccine regimen did not provide sufficient protection against HIV for young women in sub-Saharan Africa.¹

However, this investigational vaccine regimen was found to have a favorable safety profile.¹

The primary analysis was conducted 24 months after individuals received their first vaccination. The primary endpoint was the difference in number of new HIV infections between the placebo and the vaccine groups from month 7 through month 24.²

Investigators found that through month 24, 63 of 1109 individuals who received the placebo acquired HIV, and 51 of 1079 individuals who received the vaccine acquired HIV. The vaccine efficacy was estimated at 25.2%.²

However, the vaccine did not cause harm and was generally well tolerated.²

Reference

1. Janssen and global partners to discontinue phase 3 Mosaico HIV vaccine clinical trial. Janssen Pharmaceutical Companies. News release. January 18, 2023. Accessed January 18, 2023. https://www.jnj.com/janssen-and-global-partners-to-discontinue-phase-3-mosaico-hiv-vaccine-clinical-trial

2. Johnson & Johnson and global partners announce results from phase 2b Imbokodo HIV vaccine clinical trial in young women in sub-Saharan Africa. Johnson & Johnson. News release. August 31, 2021. Accessed January 18, 2023. https://www.jnj.com/johnson-johnson-and-global-partners-announce-results-from-phase-2b-imbokodo-hiv-vaccine-clinical-trial-in-young-women-in-sub-saharan-africa