A community oncologist's perspective on the advantages and challenges with precision medicine.
CANCER CARE HAS EVOLVED
from surgery as the only treatment option to broad-spectrum chemotherapy, more precise chemotherapy, and combination chemotherapy. We have arrived at the next phase of this ongoing evolution: targeted therapy.
Patients who would previously have received traditional chemotherapy are now benefitting from targeted therapy, used alone or in conjunction with traditional chemotherapy. In addition, those for whom traditional chemotherapy was not successful or not a good treatment option, can now be successfully treated with targeted therapy if they meet the eligibility criteria. The results can be dramatic.
Who Is a Candidate?
Only an estimated 7% to 8% of all patients with cancer are candidates for targeted therapies. Inclusion criteria are determined, not by the type of cancer, but by the presence of specific gene mutations.
The first classic illness to be treated with targeted therapy was chronic myeloid leukemia (CML), a disease in which nearly all patients express the BCR-ABL fusion gene, making them candidates for targeted therapies such as imatinib (Gleevec), dasatinib (Sprycel), nilotinib (Tasigna), and ponatinib (Iclusig). Remissions lasted for years and some patients may even have been cured. For other cancer types, however, a patient’s tumor tissue must be tested to determine whether an appropriate target is present.
Genetic tests for targeted cancer therapy detect mutations in the DNA of cancer cells. For the most part, these mutations are not inherited, but develop in the cancer. Knowing whether the cancer has a particular mutation can help guide the type of treatment a patient should receive, as the presence or absence of certain mutations (predictive biomarkers) is often predictive of who may benefit from these agents versus who is not likely to respond. As these targeted cancer drugs are expensive and generally only work in patients whose cancer has the “target,” genetic testing prior to treatment initiation is necessary to match the treatment with patients and the cancer types likely to benefit from them. Genetic testing, while readily available in larger cities, may not be available in smaller cities and rural areas. Medicare, Medicaid, and private payers typically cover the testing.
Targeted Therapy: Successes and Problems
There are more and more data demonstrating that matching patients to targeted therapies based on the unique molecular profile of the patient’s disease leads to improved outcomes across a variety of key measures, including overall survival. The successes are obvious. Not so obvious are the nonmedical problems.
Cost of Drugs
The drugs prescribed in targeted therapy treatment are often prohibitively expensive. Monthly averages of $5000 to $10,000 and annual totals over $100,000 are common. Orphan drugs, which are used to treat “rare” diseases, can cost $300,000 or more per year, however. Some patients will need to take these expensive drugs for the rest of their lives. Although many patients turn to patient assistance programs and foundations for help with drug costs, the availability of these mechanisms for covering drug costs is decreasing. The increased use of targeted therapies and the everrising drug costs make the current system unsustainable. If patients are to survive, reform is vital.
Payers Keeping Pace
Payers often find it difficult to keep pace with the rapid developments within the field of targeted therapies and the new treatments that gain FDA approval. In 2016 alone, 6 new drugs were approved for treating cancer and approved entities were granted 15 new indications. So far, in 2017, there are 8 new entities and 12 new indications for current entities. Payers—both national and local—need more time and education to assimilate new drugs and treatment protocols into the predetermination, approval, and claim processing systems, and manufacturers must do more to educate payers at all levels on the value proposition of new agents. It is unfair to place this burden on oncologists.
Oncologists are increasingly being asked to carry the burden of no, low, or slow pay for rapidly deployed new agents or face the moral dilemma of refraining from offering the potential best option to their patients. One possible solution is to change current regulations that prohibit manufacturers from initiating the payer education process prior to the FDA approval of their drug. This would give payers more time to learn about the specific treatment and make decisions for formulary inclusion and payment policies. Manufacturers should also give extended dating on payment for costly targeted therapies, potentially until reimbursement by insurers, to reduce the financial burden on community oncologists.
There is no doubt that targeted therapies are allowing patients to live longer. The results can be dramatic, especially those seen, to date, in patients with lung cancer, myeloma, and CML. It is unclear how many more indications research will discover that can be treated with the various targeted therapies. The next hurdle will be determining if maintenance treatment provides continuous disease-free survival once the cancer is in remission. Currently, it is difficult to know when or if to stop treatment. Yet, there is no good data to guide oncologists. Once a patient is in remission, many oncologists (including me) will stop treatment for 1 to 3 months under careful and continued monitoring. After that respite, re-staging will indicate if active treatment should resume.
In the 40-plus years that I have been treating patients with cancer, now is the most wonderful time. I see patients who 3 years ago would not have survived, myeloma patients surviving 8 years after diagnosis when a few years ago they would have survived for only 3 years, and patients with stage IV non—small cell lung cancer surpassing the previously dismal 5-year survival rates. The drugs and targeted treatments that are available today could mean these outcomes may soon become the norm.AUTHOR INFORMATION
Barry Kaplan, MD, PhD, is a practicing, board-certified oncologist/hematologist; clinical associate professor, Weill Medical College of Cornell University; and president, Queens Medical Associates.
ADDRESS FOR CORRESPONDENCE
Barry Kaplan, MD, PhD
President, Queens Medical Associates
176-60 Union Turnpike, Suite 360
Fresh Meadows, NY 11366