FDA Issues Draft Guidance on Diagnostic/Therapy Companions

(Tomomarusan/Wikimedia Commons)

The U.S. Food and Drug Administration (FDA) issued a draft of guidance to encourage the development and review of diagnostics tests to help health care professionals determine if a patient should receive a particular drug therapy or its dosage. The agency is seeking public input on the draft guidance for 60 days.

The draft document aims to provide companies with FDA’s policy for reviewing a companion diagnostic and its corresponding therapy. A common type of companion diagnostic determines if a patient has a specific gene amplification or protein over-expression that can predict if a drug might benefit or harm the patient.

An example is the FDA’s approval in 1998 of Herceptin (trastuzumab), a breast cancer drug designed to target HER2 gene amplification or HER2 protein over-expression. The drug was approved with a companion test and today testing is routinely performed on women diagnosed with breast cancer to help health care professionals determine if the patient should receive Herceptin.

The document clarifies the FDA’s definition of a companion diagnostic, and recommends early engagement between the FDA and manufacturers so that the agency’s expectations are included in development plans. In addition, the guidance indicates FDA plan to conduct simultaneous reviews of a drug or biologic therapy and its corresponding companion diagnostic.

The text identifies as well instances where FDA may approve a targeted medicine in the absence of a cleared or approved companion diagnostic. These cases will likely involve therapies intended to treat a serious or life-threatening disease or condition for which there are no available or satisfactory treatment and when the potential benefits outweigh the risks of not having a cleared or approved companion diagnostic. In these instances, the therapy could be approved first while the companion diagnostic may be approved or cleared later through the appropriate device submission process.

Read more: FDA Approves Genetic Test for Breast Cancer Treatment

*     *     *