Long-Term Immune Response Data for Investigational HIV Vaccine Revealed

Johnson & Johnson has announced long-term immune response data from the early stage APPROACH trial for the mosaic-based HIV-1 preventive vaccine regimen. In a presentation at the 22^nd International AIDS Conference (AIDS 2018) in Amsterdam, the Netherlands, the company announced that in the phase 1/2a trial, healthy volunteers who received the lead vaccine regimen maintained a robust HIV antibody response at 96 weeks, 1 year after the last vaccination.

The long-term results build on the initial data of the APPROACH trial, which were published in The Lancet on July 6, 2018.

The study enrolled 393 healthy individuals who were not infected with HIV in the United States, Rwanda, Uganda, South Africa, and Thailand, with a goal of evaluating the safety and ability of an investigational mosaic-based preventive vaccine regimen to elicit an immune response for prevention of HIV-1 infection.

The regimens used in this study are based on unique mosaic vaccines that utilize pieces of different HIV viruses and combines to elicit immune responses against a variety of strains.

“This is a preventive vaccine (not a therapeutic vaccine), so our goal is to help transform the start of the continuum—prevention.” Frank Tomaka, MD, senior director, global clinical development HIV & STI vaccines, Janssen, told Contagion®. “Our investigational vaccine regimen is designed as a ‘global vaccine’ with the aim to prevent infections due to a wide range of HIV-1 strains around the world that are responsible for the pandemic.”

To stimulate an initial immune response, each participant received an injection of Ad26.Mos.HIV at the advent of the study and 12 weeks later. Two additional vaccinations were given at week 24 and week 48 using combinations of Ad26.Mos.HIV or a different vaccine component referred to as modified Vaccinia Ankara (MVA) with or without 2 different doses of clade C HIV gp140 protein. The purpose of the method of priming followed by boosting with different vaccine components was to produce a strong and lasting immune response.

The new data presented at AIDS 2018 indicated that at 96 weeks, 1 year after the final vaccine dose, all regimens reported a favorable safety profile and there had been no reported adverse events related to the vaccine. All of the regimens maintained humoral and cellular immune responses from the vaccine.

The strongest immune response was produced by the regimen with the mosaic Ad26 as the prime and Ad26+gp140 as the boost, which achieved antibody response that was sustained up to 1 year-post vaccination in all participants that received the regimen. In addition, some recipients of the most immunogenic regimen also achieved a cellular immune response.

“APPROACH is important because it helped enable the initiation of the first efficacy study for the mosaic-based vaccine regimen…” Dr Tomaka emphasized to Contagion®, “Additional large-scale studies will be needed for licensure of the mosaic-based vaccine regimen against HIV-1. But we are optimistic that the world will find an HIV vaccine in our lifetimes.”

The next step for the mosaic vaccine is the phase 2b trial, known as Imbokodo.

The phase 2b trial began enrolling volunteers in November 2017. The goal is to enroll 2,600 young women between the ages of 18 and 35 in South Africa, Malawi, Zambia, and Zimbabwe. The trial will seek to determine the safety of the vaccine and its ability to reduce infections in the participants.

Data from the phase 2b trial are expected in 2021.