Med Device Monday: Companion Diagnostics

There are seemingly endless numbers of medical devices and medicines that have been designed and approved to (what else) help people. But medicine isn't about putting a square peg in a round hole to solve a problem: patients are human beings with endless variables, and it makes sense that the most safe and effective treatment is one that's tailored to each patient. Of course, this isn't always easy. 

Enter personalized medicine.

I've written about personalized medicine in various capacities here before. Today I'm talking about companion diagnostics. Per FDA, "Companion diagnostics are medical devices that help doctors decide which treatments to offer patients and which dosage to give, tailored specifically to the patient, says Elizabeth A. Mansfield, Ph.D., Deputy Director for Personalized Medicine in FDA's Office of In Vitro Diagnostics and Radiological Health. The companion diagnostic is essential to the safe and effective use of the drug. They go together."

For instance, one drug may work well for two people, but be contraindicated for a third patient. Companion devices would help make this determination so that everyone is treated effectively and safely.

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Companion diagnostics are designed to work with specific drugs and thus are developed in conjunction with the drug, and approval of both requires close collaboration between the device and drug centers at FDA. There's a lot to consider with this new companion program. FDA has issued a final guidance document here, and you can find a draft guidance document here.

Per FDA, "Patricia Keegan, M.D., an oncologist and supervisory medical officer in FDA’s Division of Oncology Products II, part of FDA’s drug center, explains that the agency requires a companion diagnostic test if a new drug works on a specific genetic or biological target that is present in some, but not all, patients with a certain cancer or disease. The companion diagnostic test is used to identify who would benefit from the treatment and sometimes to determine if there are patients who not only would not benefit, but could be harmed by use of a certain drug for treatment of their disease.

The process works best when development of the test begins before the drug enters clinical trials, Keegan explains, increasing the likelihood that the participants in the trials are the patients most likely to benefit from the treatment."

This all got started with Herceptin, a cancer drug approved by FDA in 1998. In about a quarter to a third of very aggressive cancers, there are high levels of a protein called HER2. The companion diagnostic test detects this protein, which can help determine if Herceptin would likely be an effective treatment for a given patient. Targeted, personalized medicine: what's not to like about that?

There are now over 20 cleared/approved companion diagnostic tests for selection of drugs to treat various diseases and conditions.  There are currently three companies that have a test for HER2. Most of the approved diagnostic tests are for cancers that exhibit a specific mutation that can be tested for. 

The regulation info on HER2 devices (product code NYQ) is here.  

One of the companies that makes the Herceptin test kit is Life Technologies. They submitted in 2005 and got their PMA approved in 2008: the approval is here. As a fun aside, Life Technologies is here in the San Diego area, and they used to be Invitrogen, which was my first real job! In 1998, before my senior in high school, I worked in R&D as a lab tech running agarose gels and mini-preps. While I didn't work on the HER2 project specifically, Invitrogen was where my passion for life sciences began! It's hard to believe that was almost 20 years ago.