Best practices for companion diagnostic and therapeutic development: translating between the stakeholders

By 2012 the pharmaceutical industry has generally recognized the value proposition offered through 'personalized medicine': shorter regulatory reviews and higher prices as a tradeoff for a more specific patient market. Examples of companion diagnostics (Cdx) exist not only in oncology, but across therapeutic areas that allow us to define treatment benefit and identify the 'best patients' for a given treatment approach or combination thereof. In the 13 years since the co-approval of trastuzumab (Herceptin(®)) from Genentech and the HercepTest(®) from Dako, the regulatory and commercial environments have yet to adopt a standard methodology for co-development and co-approval. Furthermore, a one-size-fits-all approach is unlikely to emerge despite attempts by various stakeholders to create an environment of conformity for approval and reimbursement issues. What has emerged, however, is the experience of clinical developers and commercial teams in bringing these products to market. In this article, we focus on the many factors that should be considered to successfully develop and market a companion diagnostic, based on lessons learned from recent case studies. A proposed framework of questions to be addressed at the various stages of developing highly effective companion diagnostic products is also presented.