Oxford BioTherapeutics is poised to become a key player in providing personalised medicines based on the development of novel therapeutic antibodies combined with tailored diagnostics. The integration of diagnostics and therapeutics for a specific disease has already been shown to be a highly successful approach by the commercialisation of Herceptin by Genentech and Roche. This diagnostics-therapeutics combination also referred to as companion diagnostic or theranostics is one of the most attractive fields of the biotechnology and pharmaceutical industry today. This combined approach offers many benefits including improved patient outcomes, increased speed of development of more targeted therapeutics, as well as creating new market opportunities.

Companion diagnostics will allow the rapid identification of patients who are more likely to respond and those that are most likely to fail to respond, to a given treatment regime. They also may enable the identification of the individuals at risk from adverse events when receiving therapy. This is because such companion diagnostics will not only allow the clinician to diagnose the disease they will also be able to monitor and predict drug response based on the analysis of the changes in a specific individuals’ biomarkers. Overall this diagnostics-therapeutics approach has the potential to deliver personalised therapy to each individual patient – the holy grail in terms of generating a significant improvement in patient outcomes across a whole spectrum of diseases.

With the development of more accurate disease specific biomarkers, the benefit of using diagnostic tests, as part of overall clinical development, is becoming increasingly accepted by the pharmaceutical industry. The ability to accurately measure the presence or absence of biomarkers provides valuable insights at every stage of the drug discovery and development process. It assists in gaining a better understanding of the disease mechanism and may also provide important information on the efficacy of a drug candidate and its potential side effects rapidly. In addition, diagnostics will help to determine the most appropriate patients to select and recruit for the clinical trials of a specific therapeutic.

Although concerns were initially raised about the limited market potential of personalised medicines, it is now clear that in combination with the appropriate companion diagnostic they offer significant commercial upside. This is because they clearly meet the major requirement of healthcare today providing more cost effective treatment alternatives with proven health economic benefits. There is little doubt that targeted therapies which greatly improve the patient’s response to treatment will have significant medical and commercial advantages in the increasingly competitive pharmaceutical landscape.

Cancer is one of the first therapeutic areas to have seen the successful use of diagnostic/therapeutic combinations with the launch of the Herceptin, Gleevec, and Iressa. The most commercially successful combination centres around the monoclonal antibody Herceptin (trastuzumab) which gained market approval along with a diagnostic test in the US and in Europe in 1998 and 2000 respectively for the treatment of certain types of breast cancer.

Critical to the success of Herceptin was the discovery that the patients who positively respond to the treatment are those who over-express a protein called HER2 – this allowed the development of a diagnostic test to identify the sub-segment of patients, and led to accelerated approval of the drug by the FDA. Herceptin was launched with a companion diagnostic test which enabled physicians to distinguish between normal metastases and those over-expressing HER2, thus allowing the identification of the patients most likely to respond a priori to Herceptin treatment. While the drug is only effective in a subset of patients, it still achieves over $3.5bn in annual sales.