A companion’s words of persuasion are effective.
-- Homer
Diagnostic test quality may not be something that pharmaceutical and biotechnology companies have had a lot of experience dealing with, but shortfalls in a diagnostic development program can undercut efforts to streamline clinical trials for personalized medicines.
The Pink Sheet reports that the need for a high-quality diagnostic test development program was a key message delivered by a representative from FDA’s devices center at a September 14th conference on drug/diagnostic co-development.
The conference, sponsored by the Friends of Cancer Research and Alexandria Real Estate Equities Inc., served as a discussion forum for a multi-stakeholder draft proposal aimed at enabling late-stage clinical development of drugs with companion diagnostics by quickly identifying a patient subset most likely to benefit from treatment while minimizing exposure of patients least likely to benefit.
FDA officials were generally receptive to the draft ideas put forward. However, they highlighted the threshold need for a well-characterized, high-quality diagnostic that can accurately distinguish between those patients well-suited for treatment and those unlikely to derive any benefit.
The draft conference paper presented at the meeting was developed with the goal of guiding design of Phase III trials to evaluate a drug and companion diagnostic in situations where prior studies do not provide a clear definition of the diagnostically selected population and sufficient evidence to restrict development.
The draft is intended to fill some of the stakeholder-identified gaps in FDA’s July 2011 draft guidance on vitro companion diagnostic devices. In that 12-page guidance, FDA explained how it defines a companion diagnostic and its expectations for simultaneous development and approval of a drug with the accompanying test.
However, the guidance left many in the drug and device industries wanting more details, such as the regulatory ramifications for drug/diagnostic combinations that are not developed and reviewed in parallel fashion and how laboratory-developed tests fit into the agency’s paradigm for companion diagnostics.
“Patients have to be protected by appropriately balancing the strength of the diagnostic hypothesis with the need for thorough data generation and evaluation,” the draft paper states. “We believe the appropriateness of including marker-negative patients primarily depends on the strength of the science in support of the diagnostic hypothesis (including but not limited to mechanism of action, pre‐clinical efficacy and, if known, class effect), the potential for risk to patients, and clinical data available to date,” the draft paper states.
FDA Office of Hematology and Oncology Products Director Richard Pazdur highlighted several basic principles that FDA considers when evaluating the use of biomarkers in applications submitted to the agency.
The first among these is that the companion diagnostic must be essential for use of the drug, Pazdur said. “It’s not like we’d like to have it or it might be nice to have it or we might in the future need it. It should be essential for the use of the drug when it is licensed.”
