Nikki Martin, Director of Precision Medicine Initiatives at LUNGevity, had a virtual "sit-down" with Erica Schnettler, Medical Science Liaison at OneOme, to discuss pharmacogenomics testing. Erica has her BS in genetics and PhD in pharmacology and is passionate about using PGx to improve oncology patient health outcomes.
Nikki Martin: Let’s start with basic definition of pharmacogenomics.
Erica Schnettler: How your body responds to a drug is determined by many factors. Of those factors, your genes (or variations in your DNA that make you unique) can have a major influence. In fact, genetic factors can account for up to 50-75% of how you respond to medications. Pharmacogenomics (PGx) studies the ways in which an individual’s genes affect their response to medications to help identify effective, safe medications and doses for patients.
NM: When we speak about precision medicine in the lung cancer space, we normally mean getting patients the right drug and care plan at the right time in their treatment experience. Tell us how PGx potentially can fit into precision medicine for lung cancer?
ES: PGx is emerging as an important component of precision medicine in oncology. Currently, when we think of precision medicine in cancer, it involves using tumor DNA from a biopsy to find a biomarker-driven therapy that will target the tumor, based on its mutations. The idea is that these targeted therapies will be more effective in killing the tumor and reducing the cancer.
Meanwhile, PGx tests focus more on helping clinicians predict which dose of the chemotherapy or targeted treatment and which supportive care medications may work best for the patient. The goal is to make the patient’s cancer treatment effective and tolerable by minimizing the number and severity of side effects they experience. Oncologists use PGx testing as a tool to improve patient medication safety and avoid dangerous side effects.
NM: What possible impact can running a PGx test have on a lung cancer patient?
ES: First, PGx testing may help predict which patients are at risk for developing severe side effects related to certain chemotherapies and targeted agents. In lung cancer, PGx testing may help estimate what is the safe dose of a chemotherapy (such as docetaxel, paclitaxel, or etoposide) and a targeted therapy (such as gefitinib, and erlotinib) for an individual patient. The test results can help oncologists better monitor or adjust the dose to avoid cancer drug-related side effects.
Second, it can help patients’ physicians find the optimal supportive care medications. Supportive or palliative care medications are given to patients to prevent, control, or relieve treatment-related complications and side effects (like pain, nausea, vomiting, sleep, anxiety, etc.) and to improve the patient’s comfort and overall quality of life. Unfortunately, supportive care medications don’t always work as intended or may even cause more side effects. PGx testing may be able to help identify a more effective supportive care medication and dose, reduce the number of side effects, and make patients more comfortable.
NM: We often talk to patients and their caregivers about the importance of testing for biomarkers at various times – first when the lung cancer is diagnosed and again if it progresses. How often does someone with lung cancer need to be tested with a pharmacogenomics test?
ES: Because PGx testing does not require a tumor sample or biopsy, and because the type of DNA we test does not change over time (unlike cancer cell DNA), PGx testing only needs to be performed once. PGx testing utilizes DNA that is typically isolated from cheek cells (buccal swab), saliva, or a blood sample. PGx testing is not painful for the patient. Also, as the sample collection can be done easily and processed quickly in the lab, results can typically be returned within days or weeks of sample collection.
It’s best to get PGx testing done soon after diagnosis or prior to surgery or chemotherapy to help guide prescriptions or dosing; however, PGx test results can be used to guide prescription needs at any stage or point in time during the patient’s journey with cancer.
NM: If someone wants more information about pharmacogenomics, is there a third-party site that provides information? Where can they learn more about your test?
ES: Patients can learn more about pharmacogenomics here:
National Institutes of Health – Frequently asked questions about pharmacogenomics
NM: How does someone interested in PGx testing access it? Is it as easy as requesting it from an oncologist?
ES: A patient’s oncologist can certainly order a PGx test, but it can also be ordered by a patient’s primary care physician, supportive/palliative care physician, or psychiatrist; or by any physician, nurse practitioner (NP), or physician assistant (PA) in charge of prescribing and managing the patient’s medications. One thing to note is that although PGx testing has rapidly expanded into the clinic over the past several years, the patient’s provider may not necessarily order PGx testing on a regular basis.
The cost of PGx testing varies depending on the type of test ordered and your health insurance coverage. Some insurance companies may cover pharmacogenomic testing, depending on the policy and reasons for testing. Contact your insurance provider about coverage prior to testing if cost and coverage are concerns.
Learn more about PGx testing by checking out A Patient's Story with Pharmagenomics Testing.
Nicole Martin is LUNGevity's Director of Precision Medicine Initatives