What is Vacc-4x?
- Vacc-4x is a therapeutic vaccine being developed by Bionor Pharma. A therapeutic vaccine works by controlling HIV in people who are infected with the virus.
- Vacc-4x is made up of long chains of amino acids, called peptides, which resemble the p24 proteins found on the outer coat of HIV. These peptides are injected under the skin with an immune-stimulating medicine called granulocyte macrophage-colony stimulating factor (GM-CSF). Together, the peptides and the GM-CSF cause CD4 and CD8 cells to become stimulated against HIV’s P24 proteins, with the intention of helping the immune system control the virus.
- Currently, Vacc-4x is being developed for use in combination with antiretroviral (ARV) therapy with the goal of boosting the immune response to ultimately allow for ARV treatment discontinuation.
What is already known about Vacc-4x?
- BioNor has conducted four clinical trials to assess the safety of Vacc-4x, as well as its potential to control HIV. The studies are also seeking to determine the duration of the immune response to the vaccine and the overall effect of the vaccine on CD4 counts.
- Two doses of Vacc-4x have been studied: 0.4 milligrams (mg) and 1.2mg per dose. In each study, between six and ten doses have been given over a 26-week period, in conjunction with standard ARV therapy, in people whose current HIV treatment is fully suppressing the virus. Following treatment with Vacc-4x, people then interrupted their HIV treatment.
- Early studies established that the immune system responded well to Vacc-4x, with strong and long-lasting stimulation of CD4 and CD8 cells specific to the peptides in the vaccine.
- In an early study, participants appeared to have significant gains in their CD4 counts while taking both Vacc-4x and their ARVs. The majority were also able to stay off of their ARVs for up to two-and-a-half years.
- A second, larger study, comparing Vacc-4x to a placebo was designed to determine whether those receiving the vaccine could stay off of their ARVs during a treatment interruption for a longer period than those receiving a placebo. The study also sought to determine whether those receiving Vacc-4X would maintain higher CD4 counts during the treatment interruption than those receiving a placebo. The study failed to find any major differences between the treatment and placebo groups with respect to changes in CD4 counts, prompting BioNor to announce that it was discontinuing development of Vacc-4x. However, a later analysis found that people receiving Vacc-4x maintained lower viral loads during their treatment interruption than they had prior to starting HIV treatment, and the company decided to restart development of the vaccine.
- BioNor is awaiting further analysis of the larger study to determine what strategy will be pursued in future studies.
- Like other drugs, Vacc-4x might interact with other medications, including those used to treat HIV. It is important that your personal physician and/or the research nurse or study investigator be aware of all drugs you are taking, including those you buy without a prescription.
What is known about side effects?
- In early studies, reactions at the site of the injection were the most notable side effects. However, Vacc-4x has not been studied in large trials to date, and data on the safety of the drug in the most recent placebo-controlled trial have not yet been released.
Who should not take Vacc-4x?
- It is not known whether Vacc-4x will harm an unborn baby. It is very important to treat HIV during pregnancy to reduce the risk of infecting your baby. Talk to your provider about your treatment options.
- It is not known how Vacc-4x will affect babies who are breast-feeding when the mother while the mother is being treated. To prevent transmission of the virus to uninfected babies, it is recommended that HIV-positive mothers not breast feed.
Where can I learn more about clinical trials of Vacc-4x?
- If you would like to find out if you are eligible for any clinical trials that include Vacc-4x, visit ClinicalTrials.gov, a site run by the U.S. National Institutes of Health. The site has information about all HIV-related clinical studies in the United States. For more info, you can call their toll-free number at 1-800-HIV-0440 (1-800-448-0440) or email firstname.lastname@example.org.