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Companion Diagnostics: Changing the Way Patient Care is Provided

Immunotherapy has revolutionized the treatment of cancer by harnessing the power of the human immune system to combat the disease. These new therapies help prevent cancer cells from switching off the immune system in an effort to survive, thereby allowing the immune system to detect and destroy cancerous cells.

Just like with targeted cancer therapies, not all cancer patients are potential candidates for immunotherapy. To identify those who are, doctors rely upon assays or tests known as companion or complementary diagnostics. Companion diagnostics are so named because these assays or tests are specifically developed for use as a companion to a particular drug. In addition to helping identify the right patient population, companion diagnostics may also help avoid adverse drug reactions by allowing doctors to identify patients who are at increased risk for serious side effects from certain medicines. They also give doctors the opportunity to adjust drug therapy in order to achieve better clinical results.  A new category of lab tests has recently been introduced referred to as complementary diagnostics.  These assays provide relevant information for the use of the specific therapy, and while they need to follow the same regulatory pathway as a companion diagnostic, they are not specifically required to use the associated therapy.  Examples of both companion and complementary diagnostics exist in the current immunotherapy landscape.

Commercial use of companion diagnostics began in 1998 with the U.S. Food and Drug Administration’s (FDA) approval of trastuzumab, a targeted therapeutic for the treatment of certain types of breast cancer, as well as its associated companion diagnostic assay. LabCorp developed the clinical trials assay (CTA) and served as the central lab for the testing of HER2-positive breast cancer during the development of trastuzumab. In addition, the company provided analytical testing data for the associated companion diagnostic assays, an immunohistochemistry (IHC) assay to detect HER-2 overexpression and a fluorescence in situ hybridization (FISH) assay to detect amplification of the HER-2gene in breast cancer tissues. In the nearly two decades since those approvals, there has been increasing acceptance by drug makers that companion diagnostics can improve the clinical success of certain medications by identifying patients likely to benefit from a specific treatment.

Today, more than 30 companion diagnostics are in commercial use. LabCorp has played a role in the development of more than 75 percent of them.

The development and commercialization of companion diagnostics and their associated treatments reflects all three components of LabCorp’s strategic focus – delivering world-class diagnostics, bringing innovative medicines to patients faster, and changing the way care is provided.

Precision Medicine and Personalized Medicine

Precision medicine is often used interchangeably with personalized medicine, but the latter implies that the therapy is specific for each individual.

Precision medicine is directed at delivering the right drug to the right patient at the right time. Companion diagnostics evaluate a particular feature of a person’s disease that is a target for that precise and targeted medicine. The particular feature companion diagnostics evaluates is typically a genetic or proteomic change, such as a single gene mutation or alteration in the structure or expression of a protein. For example, tumors expressing high levels of the PD-L1 protein are likely to respond to immunotherapy. In this case, as in the other examples of companion diagnostics, the genotypic or phenotypic changes driving the growth of cancer become the target of therapy.

Thanks to scientists’ improved understanding of what drives cancer development and progression, we are aware of many powerful stories about how immunotherapy and companion diagnostics are transforming the lives of patients.

Considering the insidious and nefarious nature of cancers, the tumor often has an uncanny ability to circumvent treatment.  By disabling one pathway in cancer, genetic changes may enable a second pathway. This process allows disease to become resistant to the specific therapy even after a dramatic response with the original targeted therapy using the companion diagnostic.

LabCorp and its Covance Drug Development Business (Covance) were featured on the award-winning television series Innovations with Ed Begley Jr., a show dedicated to bringing viewers the most up-to-date, cutting-edge information across a vast array of industries, showcasing practical solutions and important issues facing consumers and professional alike. The show aired on Fox Business.

As technology and scientists’ understanding of cancer biology become more sophisticated, the goal is to one day “knock back” cancer by targeting multiple disease pathways with drugs. Companion diagnostics will similarly become more complex, capable of assessing multiple genes and proteins and providing a better reflection of the biology of the disease being combatted. Developing these complex companion diagnostics presents substantial challenges, including the need for communication and coordination among the partnering drug and diagnostic developers, as well as contract research organizations (CROs).

Such close collaboration is necessary because the FDA and other regulatory agencies require that new drugs and their corresponding companion diagnostics be approved simultaneously for commercial use. An example of the changing landscape is the recent approval of the use of a specific immunotherapy across multiple tumor types, not based upon the site of origin of the tumor, but instead based upon genetic changes in the tumor that prevents the tumor cells from adequately correcting mutations.

Our Role in Companion Diagnostics

LabCorp developed the companion diagnostic for trastuzumab 20 years ago and we remain a leader in this increasingly important area. Since then, both LabCorp Diagnostics and Covance Drug Development have been involved in the development of companion diagnostics for cancers such non-small cell lung cancer (NSCLC) and melanoma, as well as the clinical trials that supported FDA approval of such drugs.

More recently, we have played a key role in implementing companion diagnostics for immunotherapies involving the expression of PD-L1, with Covance Central Laboratory Services (CLS) exclusively responsible for testing specimens for PD-L1 expression on the registration trials for pembrolizumab and nivolumab, with LabCorp being the first to commercialize the specific tests.

As pharmaceutical and biotechnology companies consider incorporating companion diagnostics earlier in the drug development process, LabCorp and Covance are uniquely positioned to support drug development partners and contribute to the development of companion and complementary diagnostics, helping patients have access to new therapies on the day the drug and the diagnostic are approved.

Did you know?
LabCorp and Covance have supported more than 75% of all FDA-approved companion and complementary diagnostic assays.

Explore Covance to learn how its full spectrum of nonclinical, clinical and commercialization services help bring new and innovative medicine to patients sooner.