MVA-BN® HER2
Therapeutic breast cancer vaccine candidate.
MVA-BN® HER2 is designed to express sequences that control
immunity to HER2-Neu antigen (HER2). HER2 is a growth factor
receptor that is over-expressed by approximately 20 - 30% of
patients with localized breast cancer, and is important for the
growth of the tumour. HER2 has been validated as a tumour antigen
target through numerous preclinical and clinical studies. This is
notably exemplified by the efficacy of Herceptin, a humanized
anti-HER2 monoclonal antibody, FDA and EMEA approved for treatment
in both metastatic and adjuvant disease settings. Active
immunotherapy against HER2 is being studied by numerous
investigators at an early stage of development using a variety of
forms of HER2 including wild-type, truncated, peptide fragments,
and modified forms. Bavarian-Nordic's approach is to utilize the
MVA-BN® vector, engineered to encode a modified form of HER2,
to generate endogenous immune response to the critical tumour
antigen.
In early 2009, Bavarian Nordic reported data from its clinical
Phase I/II studies with its breast cancer vaccine,
MVA-BN®-HER2, in development as therapy of metastatic breast
cancer patients. The study met its primary endpoint with regards to
safety and by showing an immune response.
Additionally, Bavarian Nordic has completed preclinical studies
with an improved version of the MVA-BN® HER2 vaccine. In those
studies, the new vaccine induced up to 20-fold higher T-cell immune
response as compared to the original version. Furthermore, it
proved to be efficacious in additional tumour immunotherapy models
in HER2 transgenic mice. The immunological situation regarding HER2
in those mice strongly resembles the situation in humans.
Based on those data from both clinical and preclinical studies
Bavarian Nordic decided to advance the clinical development of
MVA-BN® HER2 in further clinical studies with the new and
improved vaccine. Specifically, a new, single-site Phase I/II study
in the United States will be initiated in the first half of 2010
and evaluate 24 patients in both metastatic breast cancer as well
as in an adjuvant therapy of breast cancer setting.
