An in vitro companion diagnostic device (hereafter referred to as an “IVD companion diagnostic”) is an in vitro diagnostic device (IVD) that provides information that is essential for the safe and effective use of a corresponding therapeutic product. As described in the FDA guidance entitled “In Vitro Companion Diagnostic Devices,” in most circumstances, an IVD companion diagnostic should be approved, granted a de novo request or cleared by FDA contemporaneously with the approval of the corresponding therapeutic product for the use indicated in the therapeutic product labeling.

This guidance document is intended to be a practical guide to assist therapeutic product sponsors and IVD sponsors in developing a therapeutic product and an accompanying IVD companion diagnostic, a process referred to as codevelopment. This guidance is also intended to assist FDA staff participating in the review of candidate IVD companion diagnostics or their associated therapeutic products.