U.S. flag An official website of the United States government
  1. Home
  2. Medical Devices
  3. Products and Medical Procedures
  4. In Vitro Diagnostics
  5. Companion Diagnostics
  1. In Vitro Diagnostics

Companion Diagnostics

A companion diagnostic is a medical device, often an in vitro device, which provides information that is essential for the safe and effective use of a corresponding drug or biological product. The test helps a health care professional determine whether a particular therapeutic product’s benefits to patients will outweigh any potential serious side effects or risks.

Companion diagnostics can:

  • identify patients who are most likely to benefit from a particular therapeutic product;
  • identify patients likely to be at increased risk for serious side effects as a result of treatment with a particular therapeutic product; or
  • monitor response to treatment with a particular therapeutic product for the purpose of adjusting treatment to achieve improved safety or effectiveness.

If the diagnostic test is inaccurate, then the treatment decision based on that test may not be optimal.

On July 31, 2014 the FDA issued "Guidance for Industry: In Vitro Companion Diagnostic Devices," to help companies identify the need for companion diagnostics at an earlier stage in the drug development process and to plan for co-development of the drug and companion diagnostic test. The ultimate goal of the guidance is to stimulate early collaborations that will result in faster access to promising new treatments for patients living with serious and life-threatening diseases.

On July 15, 2016, FDA released the draft guidance, "Principles for Codevelopment of an In Vitro Companion Diagnostic Device with a Therapeutic Product." 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.

On December 7, 2018, the FDA published the draft guidance, "Developing and Labeling In Vitro Companion Diagnostic Devices for a Specific Group or Class of Oncology Therapeutic Products" which, if finalized, is intended to facilitate class labeling on diagnostic tests for oncology therapeutic products, where scientifically appropriate. This draft guidance notes that in some cases, if evidence is sufficient to conclude that the companion diagnostic is appropriate for use with a specific group or class of therapeutic products, the companion diagnostic’s intended use should name the specific group or class of therapeutic products, rather than specific products. A 60-day public comment period will last until February 5, 2019. Electronic comments should be submitted through www.regulations.gov. Written comments may be submitted to Dockets Management Staff (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852. Identify comments with Docket No. FDA-2018-D-3380.

Additional Information

Back to Top