Vacc-4x is being developed by Bionor Immuno AS as a therapeutic
vaccine to be used in conjunction with antiretroviral
therapies by individuals infected with HIV. The
vaccine is comprised of four synthetic
peptides describing sequences from within the highly conserved
HIV core protein p24, which are thought to induce T-cell-mediated responses.
Vacc-4x was assessed in 51 patients infected with HIV in one phase I and one phase II clinical trial and was demonstrated to be safe and generally well tolerated with no significant adverse events. Promisingly, the
vaccine was reported to induce cell-mediated immunity, with a third of vaccinees eligible for follow-up remaining off antiretroviral
therapy and being essentially symptom-free 4 years
after treatment. Nonetheless, without the inclusion of a placebo group, the data will be looked upon with a degree of skepticism in the scientific community. A phase IIb, placebo-controlled clinical trial to address this issue is currently ongoing, with data expected to become available by the end of 2010. If
Vacc-4x vaccinees demonstrate significantly better responses than the placebo group in this trial, the prospects for
Vacc-4x could be highly promising.