THE HVTN 705/HPX2008 or Imbokodo study, which began in 2017 to test whether the Imbokodo vaccine regimen could prevent women in Sub-Saharfan Africa from getting HIV has been discontinued following indications that the vaccine did not provide sufficient protection against infection.
By Michael Gwarisa
In a statement, Johnson & Johnson said data showed the investigational HIV vaccine regimen did not provide sufficient protection against HIV infection in a population of young women in sub–Saharan Africa at high risk of acquiring HIV even though the investigational vaccine was found to have a favorable safety profile with no serious adverse events,
We are extremely grateful to the women who volunteered for the Imbokodo study, and to our partners, including the people on the frontlines, all of whom are contributing every day to this enduring quest to make HIV history,” said Paul Stoffels, M.D., Vice Chairman of the Executive Committee and Chief Scientific Officer at Johnson & Johnson.
“HIV is a unique and complex virus that has long posed unprecedented challenges for vaccine development because of its ability to attack, hijack and evade the human immune system. While we are disappointed that the vaccine candidate did not provide a sufficiant level of protection against HIV infection in the Imbokodo trial, the study will give us important scientific findings in the ongoing pursuit for a vaccine to prevent HIV. We continue to stand
in solidarity with people living with and vulnerable to HIV, and remain committed to furthering our research against this devastating virus.”
In parallel to the Phase 2b Imbokodo HIV vaccine trial, Janssen is sponsoring the ongoing Phase 3 Mosaico study (HVTN706/HPX3002) which is testing the safety and efficacy of a different composition of the HIV vaccine regimen among men who have sex with men (MSM) and transgender individuals. This study is being
conducted in the Americas and Europe where different strains of HIV are circulating.
The Imbokodo vaccine regimen was administered to participants through four vaccination visits over one year. The primary analysis was conducted 24 months after participants received their first vaccinations. The study’s primary endpoint was based on the difference in number of new HIV infections between the placebo and vaccine groups from month seven (one month after the third vaccination timepoint) through month 24. These data found that through 24 months of follow up, 63 of 1,109 participants who received placebo compared to 51 of 1,079 participants who received active vaccine acquired HIV. This analysis demonstrated a vaccine efficacy point estimate of 25.2% (95% confidence interval of -10.5% to 49.3%).
The vaccine regimen did not cause harm and was generally well-tolerated. “The high incidence of HIV among young women in sub-Saharan Africa reminds us that, despite great progress made in treatment and prevention, HIV remains a major health challenge for the region,” said Professor Glenda Gray, President and Chief Executive Officer, South Africa Medical Research Council (SAMRC) and Imbokodo’s Protocol Chair1.
“This underscores the need to apply the knowledge that will be gained from this trial to continue to advance the pursuit of a global HIV vaccine.”
The Imbokodo study tested an investigational HIV regimen with an adenovirus vector containing four mosaic immunogens (Ad26.Mos4.HIV) at four vaccination visits over one year. The Imbokodo regimen contains a soluble protein component (Clade C gp140, adjuvanted with aluminum phosphate) which is administered at vaccination visits three and four. The ongoing Phase 3 Mosaico study is testing a different investigational vaccine regimen that involves the administration of a mosaic-based mixture of soluble proteins (Clade C/Mosaic gp140) at vaccination visits three and four.
