Bionor Immuno trials new innovative therapeutic immunization designed to help existing HIV and AIDS patients

Aug 4 2008

Bionor Immuno today announced that it has advanced its efforts to develop the first HIV therapeutic immunization with the dosing of patients in a global Phase 2b clinical trial of the company's lead candidate (Vacc-4x).

This randomized, double-blind, placebo-controlled trial is being conducted in HIV infected patients with the potential to offer an important drug free break in their current antiretroviral therapy. The company anticipates that trial results will be available by year end 2009.

"The commencement of this global Phase 2b study represents an important milestone in the clinical development of our Vacc-4x therapeutic peptide candidate," said Birger Sørensen, President and CEO of Bionor Immuno. "In previous clinical studies, this peptide therapeutic candidate has demonstrated promising results in T-cell stimulation of the immune system in HIV patients. Bionor is excited to provide a potential significant step forward for treatment alternatives in the management of HIV disease."

Earlier observations of HIV patients showed that sustained immune responses to the protein p24 in the HIV virus were associated with delayed disease progression. Building on this observation, Vacc-4x is comprised of 4 modified synthetic peptides, each of which correspond to a conserved domain of the p24 protein. The modified peptides in Vacc-4x are designed to amplify and extend immunity to this protein, which could allow for extended drug free periods and may delay disease progression.

Dr. Barry Peters, Head of the Academic Unit of HIV & STDs at the Guys & St Thomas' site of Kings College London, is leading the research in the UK and has 20 years of clinical experience of managing people with HIV infection. He says: "A successful immunotherapeutic HIV vaccine would give patients and doctors enormous advantages over current treatments, both in developed and developing countries. Even if this vaccine is not the final answer, it could help the march towards a successful immunotherapeutic HIV vaccine."

Dr. Richard Pollard, Head of the Infectious Diseases Division at The University of California, Davis Medical School, Sacramento, California, says "this is the largest current therapeutic vaccine trial in the world involving 345 patients. This trial will establish a solid foundation for HIV immune therapies if we can maintain immunogenicity during drug free periods.

About Vacc-4x Peptide Therapeutic Candidate

Vacc-4x has been tested in two clinical trials exposing the vaccine to 11 and 38 HIV patients, respectively. In both studies the vaccine was found to be safe and well tolerated. In the phase IIa study comprising 38 patients, the primary objective was to measure immune responses to Vacc-4x. Subjects were initially maintained stable on ART (Antiretroviral Therapy) while treated over a period of 26 weeks with a series of Vacc-4x immunizations at a low dose (LD) or high dose (HD). This immunization phase included also an ART-free window during which endogenous antigen stimulation was allowed.

• The majority of subjects experienced a pronounced therapeutic effect allowing them to remain off ART following completion of the study (Week 52). While being off ART the patients CD4+ cell counts remained high above the level they had before they had ART commenced by their treating physician.
• Due to this pronounced clinical response permission was granted to follow the subjects until they resumed ART. The median treatment interruption achieved for all subjects in the Vacc-4x Phase IIa clinical study was 31 months. The duration of treatment interruption was linked to immune responsiveness to the peptides.
• At a follow up 44 months after treatment interruption, 34% of the patients were still not back on ART treatment. For the full appreciation of these unique data it should be noted that previous experience has shown that ART usually cannot be interrupted for more than 3-4 months.