Dr. Colin Pritchard, one of the key developers of UW-OncoPlex, believes that the test’s diagnostic capability is the beginning of a “paradigm shift in cancer treatment.” He immediately adds the caveat: “We are still in early days of this model.”
The ongoing challenge will be adding more genes to the panel. Technically this is not difficult. The platform is easily scalable.
Actionable mutations wanted
What’s needed to add more genes to the panel is the identification of more actionable mutations. John Thompson, MD, an SCCA melanoma specialist, points out that researchers have already identified more than 1,000 mutations. But most of these are irrelevant “passenger mutations and not driver mutations,” Dr. Thompson says. “As clinicians, what we want are the driver mutations, the ones that are making the cancer happen and the ones for which we have a treatment.”
Fortunately, this is precisely the type of research that scientists are tackling in laboratories all over the world. Dr. Pritchard says that many clinical trials are now using the presence or absence of a particular mutation as one of the enrollment criteria. “Even if only 10 percent of these drugs actually get FDA approval, that's still going to be a large increase in the number of options that oncologists have to treat their patients with different targeted therapies,” Dr. Pritchard says.
A new look at efficacy
UW-OncoPlex and other multi-marker cancer-sequencing tests are likely to have a big impact on the design of clinical trials in years to come. Renato Martins, MD, MPH, SCCA’s head of outpatient general oncology/hematology points out that the currently known driver mutations for lung cancer are present in only a small percentage of patients—from one to 10 percent. “It will be challenging to support clinical trials for these ever-smaller populations,” Dr. Martins says. “This will likely encourage more cooperation between academic centers, because one single place is not likely to have enough patients with the characteristics needed to complete the trial in a timely fashion.”
Taking this argument a step further, Elihu Estey, MD, a widely respected authority on leukemia, wonders if the current definition of statistical significance will have to be reexamined. He observes that, currently, the standard of care is based on randomized trials with large populations of patients. “One of the interesting things with UW-OncoPlex and other types of Precision Medicine will be how close we can get to certainty,” Dr. Estey says. “Once we’re very close, we won’t need to do randomized trials. I’m not sure we’ll get there in my lifetime, but UW-OncoPlex is an important step in the right direction.”
Turning lethal cancers into chronic diseases
Dr. Pritchard agrees that time will be needed to bring UW-OncoPlex to its full potential. He believes that most cancers will probably require therapies that hit multiple targets—analogous to how researchers combine multiple drugs to keep human immunodeficiency virus (HIV) under control. “I think SCCA truly is at the forefront of Precision Medicine with this test,” says Dr. Pritchard. “It has already become the standard of care for certain patient populations here. And as we identify more driver mutations with actionable targeted therapies, I believe that, within 15 years, we'll develop highly effective combination treatments that can turn some of the most lethal cancers into chronic diseases. I'm quite optimistic about that.”