US FDA consults on companion diagnostics

The US Food and Drug Administration yesterday issued a new draft guidance to facilitate the development and review of companion diagnostics – tests used to help health care professionals determine whether a patient with a particular disease or condition should receive a particular drug therapy or how much of the drug to give.

As part of agency's efforts to promote development of personalized medicines and diagnostics, the draft document is intended to provide companies with guidance on the agency's policy for reviewing a companion diagnostic and the corresponding therapy, the FDA stated.

One common type of companion diagnostic looks for whether a patient has a specific gene amplification or protein over-expression that could predict whether a drug might benefit the patient or lead to harm. For example, the FDA in 1998 approved Roche’s 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 whether or not the patient should receive Herceptin.