The U.S. Food and Drug Administration (FDA) has issued a final guidance on the development, review, and approval or clearance of companion diagnostics and is intending to publish a proposed risk-based oversight framework for laboratory developed tests (LDTs).

The companion diagnostics guidance is intended to assist companies in identifying the need for tests used to pinpoint patients who will benefit from or be harmed by treatment with a particular drug. These tests are aimed at assisting physicians in determining suitable treatments for individual patients and are often used to detect certain types of gene-based cancers.

The agency is also notifying Congress of its intention to publish a proposed risk-based oversight framework for LDTs; these tests are designed, manufactured, and utilized within a single laboratory and include some genetics tests used by healthcare professionals to guide patient medical treatment. Direct-to-consumer tests are already regulated by the FDA whether or not they are LDTs or traditional diagnostics.

RELATED: The App Will See You Now: Smartphones as Diagnostic Devices

The FDA states that while it has historically exercised enforcement discretion over LDTs, current ones lacking support from clinical trials evaluating their accuracy and efficacy may be competing with FDA-approved tests. Inaccurate test results may cause a patient to seek unnecessary treatment, or to delay or forgo treatment entirely. Enforcement discretion will be exercised for low-risk LDTs, LDTs for rare diseases, and, under specific circumstances, LDTs for which no FDA-approved or cleared test exists.

A draft guidance explaining how laboratories can notify the FDA that they are currently manufacturing and using LDTs will also be published by the FDA and will include steps on how laboratories can provide information about their LDTs and comply with the medical device reporting requirements.

For more information visit