The importance of companion diagnostic development and approval as an essential corollary to the development of stratified medicines continues to attract attention.
In July 2011, US regulator the FDA announced that approval of new forms of stratified medicines was likely to require simultaneous approval of the relevant companion diagnostic, to accurately define the patient population for whom the medicine was suitable (see previous news).
M. Trevor Page, director of business development at diagnostics company Dako, which recently agreed to collaborate with pharmaceutical company Genentech on the regulatory submission of companion diagnostic tests alongside a new drug candidate for HER2-positive breast cancer, commented: “The tests are becoming almost gatekeepers to the drug”.
Diagnostics 2011, a report released by Price Waterhouse Cooper launched in December, notes a surge in partnerships between pharmaceutical and diagnostics companies prompted by this expanding area, as well as acquisitions of molecular and tissue diagnostics companies by larger pharma. However, it warns that the momentum of this trend will depend on government, regulatory and industry efforts to support innovation.
Comment: This is indeed a complex situation requiring ongoing oversight. Experts warn that there are many ‘economic, scientific and regulatory obstacles to developing companion diagnostics’, not least the difficulty of coordinating drug and diagnostic development when the scope of a new drug’s target population often becomes clear only at late stages. Pharmaceutical companies would greatly prefer to produce drugs that are licensed for broader use wherever possible, since the financial returns are much greater, but can see the value in producing a stratified medicine from a promising compound if it proves ineffective in the general population. At the same time, the typically smaller diagnostics companies face financial risks in developing tests for drugs that may not prove effective or reach the market at all.