FAQs
Companion Diagnostics & Biomarker Strategy

Q13: What clinical evidence does FDA require to approve a companion diagnostic?

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Clinical evidence requirements for a companion diagnostic (CDx) are heavily influenced by the novelty of the biomarker, the relationship to the therapy, the target population, and the consequences of a false result. All these factors provide context for the appropriate study design and submission package to secure agency approval.

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For established biomarkers with prior approvals, the  FDA has accepted concordance data from archived specimens combined with clinical outcome data from the associated therapeutic trial. For a novel biomarker or intended use claim, the FDA usually expects prospective clinical trial data with a clear pre-specified analysis plan.

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Clinical evidence must support all aspects of the intended use statement. This includes the patient population, the decision threshold for the biomarker cutoff, the specimen type, and the therapeutic context. Evidence that doesn’t match the labeled claim will generate deficiencies that impact the approval process. Landrich Group advises CDx developers on clinical evidence strategy and pre-submission meeting preparation to define the right evidence package before studies begin.  Conducting pre-sub meetings with the FDA is an effective means for mitigating risks that the FDA will have objections to the CDx study design, acceptance criteria, or clinical endpoints.  

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