Originally published Jan. 24. This article has been updated to include comments from Crescendo Bioscience's Ted Snelgrove, who spoke at a personalized medicine conference this week in Mt. View, Calif.
When oncologists use Genomic Health's Oncotype DX colon cancer recurrence test, they change their treatment recommendations in 29 percent of cases, according to the results of a clinical decision-making study.
"These new results support our efforts to gain broad reimbursement coverage and increase patient access, and highlight the independent value beyond conventional measures that the test provides to physicians, patients, and payors," Steve Shak, Genomic Health's chief medical officer, said in a statement.
Although Medicare contractor Palmetto GBA extended coverage for the colon cancer test last year, Wall Street has been skeptical that the colon cancer test will be as successful as Genomic Health's flagship breast cancer recurrence test without a study validating the test's predictive capabilities.
Genomic Health co-developed the Oncotype DX colon cancer recurrence test with the National Surgical Adjuvant Breast and Bowel Project and the Cleveland Clinic. In clinical trials, Genomic Health has been able to show that the 12-gene expression RT-PCR-based test assesses the risk of colon cancer recurrence in patients with stage II disease, but the test has not yet been validated as a tool for predicting chemotherapy benefit.
The Quick and Simple and Reliable, or QUASAR, study validated Oncotype DX for the assessment of colon cancer recurrence risk in patients with stage II disease who have been treated with surgery. The test's recurrence score was found to have prognostic value compared to other recurrence risk measures such as T-stage and mismatch repair protein status. The QUASAR study, however, did not prove that the recurrence score was predictive of chemotherapy benefit (PGx Reporter 11/9/2011).
Still, according to the latest clinical decision study, it appears that oncologists are already using the test to influence their treatment decisions for colon cancer patients. For the study, researchers form Genomic Health and elsewhere surveyed US medical oncologists who had tested three or more patients with the Oncotype DX colon cancer test and gauged how the test's recurrence score impacted their treatment decisions.
"Out of the 92 patients who had treatment recommendations before having Oncotype DX testing, physicians changed treatment recommendations based on the recurrence score results in 27 patients (29 percent)," Genomic Health reported.
Of the 27 patients who had treatment changes based on Oncotype DX testing, 67 percent of the time doctors recommended a decrease in the "intensity" of the treatment. For example, doctors recommended stopping chemotherapy and just observing the patient, or suggested treatment with fluoropyrimidine monotherapy instead of an oxaliplatin-containing chemotherapy. Meanwhile, 33 percent of the treatment changes involved increasing the intensity of the medical intervention.
Genomic Health presented data from this study at the Gastrointestinal Cancers Symposium in San Francisco last week.
The rate at which the Oncotype DX colon cancer test influences clinical decisions is similar to Genomic Health's breast cancer recurrence test, which also has a change rate of approximately 30 percent when used by oncologists to inform treatment decisions for early-stage breast cancer patients.
Physicians' rate of decision change that results from their use of the Oncotype DX tests may be a target that other companies should shoot for, Ted Snelgrove, chief commercial officer at Crescendo Bioscience and formerly VP of sales and marketing at Genomic Health, reflected this week at a personalized medicine conference in Mt. View, Calif. According to Snelgrove, a diagnostic that changes physicians' decisions 10 percent to 15 percent of the time may not be perceived as clinically useful. Meanwhile, a test that changes decisions as much as 40 percent to 50 percent of the time may also have an adoption problem because "doctors don't want to believe they're that bad at their job." However, a test that docs can use to alter their decisions around 30 percent of the time may be the "sweet spot" when it comes to driving adoption of a test, Snelgrove said.
David Ferreiro, an analyst from investment firm Oppeheimer, wrote in a research note that the findings of the clinical decision study are a "step in the right direction," and maintained his "perform" rating for the company.
Nevertheless, he noted that the Oncotype DX colon cancer test is still not indicated for prediction of chemotherapy benefit. "We believe this was key to Oncotype DX's node negative breast cancer success and think that Oncotype DX's colon cancer test launch will be stymied without the same benefit."
Genomic Health and the Mayo Clinic Cancer Research Consortium Clinical Trial are conducting a prospectively designed study to investigate whether the Oncotype DX recurrence score can help oncologists with adjuvant therapy decision-making for stage II colon cancer patients. Additionally, Genomic Health is also performing a large gene identification study to assess the test's ability to predict oxaliplatin benefit in stage II and III colon cancer patients.
The colon cancer test represents a significant revenue opportunity for Genomic Health, since around 150,000 people in the world are currently diagnosed with stage II disease. "The indication represents a real diagnostic opportunity, especially when [mismatch repair] status and chemotherapy benefit are added alongside test results," Ferreiro wrote in his note.
He projected that the company would sell between 1,129 and 1,438 colon cancer tests in 2011 and 2012, respectively.