NEW YORK (GenomeWeb) – Myriad Genetics this week presented data from two studies involving its myPlan Lung Cancer test, which the company is hoping will bolster its reimbursement prospects ahead of full commercialization.
At the Association for the Study of Lung Cancer's world conference, Myriad presented data from one study that validated the test's ability to analyze formalin-fixed paraffin-embedded tissue samples and a second study that compared the test's ability to assess risk of progression to standard guidelines, which are based on pathological features.
Myriad initiated a phased market introduction of the test in October 2013, allowing some doctors early access. MyPlan Lung Cancer gauges the expression of 31 cell cycle progression genes. The firm is marketing the test as a tool oncologists can use in addition to the pathological features of a tumor to improve their ability to determine if an early-stage lung cancer patient is at risk of dying from lung cancer in five years.
So far, the company has conducted three validation studies. In a paper published earlier this year in the Journal of Thoracic Oncology, researchers from Myriad Genetics used myPlan to analyze tumor samples from 650 stage I and II lung adenocarcinomas, and found that the gene expression test and pathological staging together predicted lung cancer mortality better than staging information alone.
In another study published this year in the European Journal of Cancer, researchers analyzed samples from 485 early-stage lung cancer patients and concluded that the addition of the gene expression score on top of staging information improved risk assessments. "The threefold higher risk in the high-risk group defines a subset of patients that should consider therapeutic choices to improve outcome," the study authors wrote.
In a third abstract presented at the American Society of Clinical Oncology's annual meeting in June, Myriad researchers analyzed samples from 1,200 stage I adenocarcinoma patients and showed that in the Stage IB cohort, the gene expression test score and pathological staging provided prognostic risk information "above" what can be gleaned from using high-risk features described in the National Comprehensive Cancer Network's guidelines.
"There is a lot of variability in how stage IB patients are medically managed following surgical resection," Myriad spokesperson Ron Rogers told GenomeWeb. "NCCN guidelines state that physicians can consider adjuvant chemotherapy treatment for patients presenting with high-risk factors, but the guidelines do not state how many high-risk factors constitute 'high risk,' how the different factors should be weighted, or how combinations of different high- and low-risk features should be interpreted."
Moreover, there is uncertainty in the field as to whether to treat stage I lung cancer patients with adjuvant chemotherapy. A test that improves identification of patients at high risk of progression at an early point in their disease would help doctors decide which stage I patients to prescribe chemotherapy.
In one of the studies presented this week, researchers from the University of Southern California and Myriad presented data demonstrating how risk determinations vary when using myPlan versus standard guidelines. They looked at the experience of more than 270 Stage IB lung adenocarcinoma patients who were tested on myPlan over the last 18 months within the early access program, and concluded that a proportion of patients who would be deemed 'low risk' by NCCN guidelines alone would be classified as 'high risk' after considering the gene expression score.
In a poster describing the study results, researchers highlighted the experience of a 71-year-old man with a pulmonary nodule who had a 45 pack-year smoking history, but who had quit smoking 30 years ago. He had a pacemaker and suffered from coronary artery disease. Moreover, he had several of the NCCN's high-risk features, which factor in tumor size greater than 4 cm, cell differentiation, vascular invasion, wedge resection, visceral pleural involvement, and incomplete evaluation of the lymph node.
Based on these factors, two oncologists decided to observe the patient, one considered chemotherapy as a possibility, and another suggested a lobectomy. Factoring in myPlan results plus staging information, the patient received a high risk score — denoting a 30 percent risk of dying from lung cancer in five years — and was given chemotherapy. At 18 months, the patient doesn't have any evidence of recurrence, the researchers, led by Myriad's Anne-Renee Hartman, reported in the poster.
Overall, the study showed that based on the prognostic score — the gene expression result plus pathological stage — 66 percent of patients in the study were at high risk of cancer progression. There were 74 patients who received a high prognostic score that had between three and five of the NCCN high risk features; 106 patients who had one or two high risk features; and 3 who had none of the NCCN high risk features.
The latest study, however, involved early-stage lung cancer patients at the beginning of their treatment, so it's unknown how many of those who myPlan deemed at high risk actually experienced progression in five years.
"Current pathological features both underestimate and overestimate risk," Rogers said. "The goal of this study was to highlight the considerable variability in assessed risk as determined by classical high risk factors and the molecular test for patients with stage IB disease."
In presenting how risk stratifications differed between NCCN features and the test results, Myriad is hoping physicians will be able to "derive their own conclusions as to the relative value of any one or combination of high risk factors when compared to a molecular risk assessment," Rogers said.
Myriad expects to fully commercialize myPlan after discussions with payors and after some coverage decisions have come in. The company presented a study last year, which compared the cost effectiveness of myPlan against the standard of care when used to determine whether to treat stage I and II patients with chemotherapy. The model found that myPlan would direct more patients to chemotherapy compared to standard methods. Still, myPlan was cost effective 51 percent of the time at a willingness-to-pay-threshold of $50,000 per quality-adjusted life years (QALY) gained and around 85 percent of the time at $100,000 per QALY gained.
The analysis has been submitted for publication, Rogers said, but he would not speculate on the timing and nature of Myriad's discussions with payors about myPlan.
Test adoption in the early access program has been "very good," he added, with most of the interest coming from thoracic surgeons, who first treat Stage I and II lung cancer patients. "Regardless of medical specialty … the test has seen the greatest uptake in the Stage IB patient population," Rogers said.