Issue link: http://digital.copcomm.com/i/857677
4 0 | PULSE S u m m e r 2 0 1 7 By using liquid biopsies to identify and target specific mutations, physicians can offer more individualized cancer care. For instance, one of the clinical trials open at Torrance Memorial Physician Network–Cancer Care focuses on patients who have run out of standard treatment options for their cancer. When this is the case, they can have a liquid biopsy. If they find a specific mutation in a gene, such as BRAF, EGFR or sonic hedgehog (yes, the actual name of a gene), then the patient can qualify for a drug that targets the protein produced by these mutant genes, Dr. Horodner explains. By enrolling in the clinical trial, the patients are provided the drug by the sponsoring company, Science 37, at no cost to them or their insurance companies. Research has also found that mutations can develop while a patient is on anti-cancer therapy, leading to resistance and tumor growth. While a traditional tumor biopsy provides a static snapshot of the genetic profile of a cancer, a liquid biopsy can help provide a picture of how a tumor changes over time. "It's becoming clear that treatment can result in new changes in the cancer that alter the DNA profile. at may open new opportunities to treat with a second targeted drug ," says Dr. Chan. ADDED BENEFITS FOR PATIENTS Because there are so many clinical trials at Torrance Memorial Physician Network–Cancer Care, many patients can be involved in more than one clinical trial over the course of their treatment, which can be valuable when an initial treatment isn't effective. For instance, because Torrance Memorial Physician Network–Cancer Care works with the research network DAVA, the hospital can offer a trial for non-small cell lung cancer patients for whom first line therapy has not worked. e study looks for the Exon 14 skipping mutation. If found, patients can qualify for a therapy aimed at this mutation. Liquid biopsies for cancer diagnosis and monitoring are not yet standard of care, and some of the treatments targeting specific mutations on these trials do not yet have FDA approval. "At Torrance Memorial Physician Network–Cancer Care, we are on the cutting edge in terms of using these tests to guide treatment decisions and in terms of having clinical trials available to our patients," notes Dr. Horodner. "Our patients can use the results of these tests to gain access to treatments not readily available to the general public by enrolling in our clinical trials. Oncologists from other clinics can refer patients to us if they have exhausted treatment options and their patients have these targetable mutations." Finding these new mutations, and having treatment available for them, has directly benefited patients. For instance, a patient treated with Tarceva for a type of lung cancer with a EGFR gene mutation was doing well for awhile, but her cancer started to worsen. Dr. Horodner and colleagues did a liquid biopsy and found the tumor developed a driver mutation called T790M, for which the FDA has an approved drug named Tagrisso. "Our patient was able to receive this drug and her disease is responding well. She has minimal side effects." THE FUTURE OF LIQUID BIOPSY Although the promise of liquid biopsies is great, it wasn't until June 2016 that the FDA approved the first liquid biopsy for use in cancer. Known as the Cobas EGFR Mutation Test v2, the test picks up certain mutations in the epidermal growth factor receptor (EGFR) gene that makes patients with advanced non-small cell lung cancer eligible for treatment with Tarceva (erlotinib), which targets EGFR mutations. More approvals are likely on the horizon, but first liquid biopsy testing must prove it can detect alterations in genes consistent with what is detected by using traditional tumor biopsy methods. "With time and maturation of data and promising results, these tests will likely become part of the standard oncology diagnostic algorithm," says medical oncologist Andrew Horodner, MD.