A phase 3 trial evaluating Janssen’s investigational HIV vaccine for the prevention of HIV-1 infection in HIV-1 seronegative cisgender men and transgender individuals will be discontinued.

The multicenter, randomized, double-blind, placebo-controlled Mosaico trial (ClinicalTrials.gov Identifier: NCT03964415) included approximately 3900 cisgender men and transgender individuals who have sex with cisgender men and/or transgender individuals who are at increased risk for HIV-1 infection. Study participants were required to be HIV-1 seronegative 28 days prior to the first vaccination.

Participants were randomly assigned to receive either placebo or the investigational HIV vaccine regimen, which contained a mosaic-based adenovirus serotype 26 vector (Ad26.Mos4.HIV) administered during 4 vaccination visits over 1 year, and a mix of soluble proteins (Clade C/Mosaic gp140, adjuvanted with aluminum phosphate) given at the third and fourth visit. The primary endpoint was vaccine efficacy based on the number of HIV-1 infections in the vaccine group compared with the placebo group between month 7 and month 24 to 30.

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The decision to discontinue the study was made based on an analysis from an independent data and safety monitoring board, which concluded that the primary endpoint was not expected to be met. Compared with placebo, the vaccine regimen was not observed to be effective in preventing HIV infection. There were no safety issues noted with the vaccine regimen.

“We are disappointed with this outcome and stand in solidarity with the people and communities vulnerable to and affected by HIV,” said Penny Heaton, MD, Global Therapeutic Area Head, Vaccines, Janssen Research & Development, LLC. “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.”


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

This article originally appeared on MPR