Originally Published May 3.
By Turna Ray
New analysis has shown that Biodesix's serum-based VeriStrat test is able to identify non-small cell lung cancer patients most likely to benefit from the anti-EGFR tyrosine kinase-inhibitor Tarceva (erlotinib), the company said last week.
VeriStrat, which costs $2,860, operates on a mass spectrometry-based platform and uses Biodesix's proprietary algorithms to determine if second-line NSCLC patients are "VeriStrat Good," meaning they will benefit from EGFR-tyrosine kinase inhibitors, or are "VeriStrat Poor," meaning they will not benefit from such treatment.
The company launched the predictive test commercially in May 2009, and in December began marketing it to community oncologists as a tool to guide NSCLC treatment with EGFR-TKIs (PGx Reporter 12/02/09).
At the European Lung Cancer Conference last week in Geneva, Biodesix presented a new subset analysis of a multi-center Phase III study that showed that VeriStrat was able to identify NSCLC patients most likely to have a "significant survival benefit" from treatment with Tarceva.
The investigation — a retrospective proteomic analysis involving 441 of 729 patients in the NCIC Clinical Trials Group Study BR.21 — revealed that after treatment with Tarceva, patients in the group classified as “VeriStrat Good” had a median survival of 10.5 months compared to 4 months in the group classified as “VeriStrat Poor.” The median survival of the general study population, ahead of genetic stratification, was 6.7 months.
"The new data validate the utility of VeriStrat in a previously treated lung cancer population with single agent erlotinib," Paul Beresford, Biodesix's VP of business development and strategic marketing, told Pharmacogenomics Reporter this week. "We believe the test has additional utility with other EGFR inhibitors and tumor types and will be conducting additional studies to further expand the intended use of VeriStrat."
So far, VeriStrat has been validated in clinical studies with over 1,000 patients, the company claims. Patient samples are analyzed at Biodesix's CLIA-certified laboratory and results are reported typically within 72 hours of sample shipment, according to the company.
In the recently reported study, patients who were treated with erlotinib and identified as VeriStrat Good experienced a significant improvement in survival of 10.5 months compared to 6.6 months on placebo. In comparison, VeriStrat Poor patients treated with erlotinib had a median survival of 4.0 months compared to 3.1 months on placebo. Additionally, VeriStrat Good patients also had a significantly higher tumor response rate than VeriStrat Poor patients.
According to Biodesix, one of the main advantages of VeriStrat is that it is a serum-based test, particularly because second-line lung cancer patients often don't have available tissue. "We analyze serum, not tissue, which is very important for a patient population that has multiple comorbidities and cannot undergo surgical procedures," Beresford said.
VeriStrat analyzes patients' specific proteomic profile in their serum to determine if the patient is likely or not likely to benefit from Tarceva. Specifically, the company explained that VeriStrat measures eight selected differentiating proteomic peaks "related to host-tumor interactions."
Previously, a Biodesix employee had suggested that VeriStrat may fall under the US Food and Drug Administration's definition of an in vitro diagnostic multivariate index assay, a subset of laboratory-developed tests the agency has said it intends to regulate. But the company has said it plans to continue to market the test as a homebrew until more definitive regulatory guidance from the FDA.
Tarceva is manufactured by Genentech and OSI Pharmaceuticals in the US and by Roche outside the US. Genentech is a subsidiary of Roche.
The drug, which costs around $3,500 per month according to reports, is indicated for the treatment of advanced NSCLC patients whose cancer has spread after receiving at least one chemotherapy regimen, or for patients whose disease has not spread after initial chemotherapy treatment.
Beresford said that Biodesix would welcome the opportunity to partner with Tarceva's sponsors in the US and abroad to market the drug with VeriStrat as a companion test.
None of Tarceva's sponsors have announced any intent to market Tarceva with a companion test. However, drug makers have been increasingly investing to personalize NSCLC drugs with companion genetic tests. For example, AstraZeneca is currently paying for EGFR mutation analysis ahead of prescribing the NSCLC drug Iressa under a patient access scheme with the UK's National Health Service (PGx Reporter 04/07/10).
Qiagen subsidiary DxS is working with Boehringer Ingelheim to develop an EGFR test for the investigational NSCLC drug BIBW2992. Pfizer's NSCLC drug PF-02341066, currently in early clinical studies, is being advanced with a companion test from Abbott Molecular that detects anaplastic lymphoma kinase translocation gene rearrangements (PGx Reporter 09/02/10).
Since launching the test last year, Biodesix has also been working with payor and physician groups to drive adoption of VeriStrat. "We have also discussed potential collaboration efforts with Medco and the UK's National Institute for Health and Clinical Excellence," Beresford said.
Targeted stratification of NSCLC to improve patient outcomes is something that payors are likely to be interested in since survival rates are low and cancer treatments are costly. According to the American Cancer Society, lung cancer is the leading cause of cancer death in the US. NSCLC represents approximately 87 percent of lung cancer, with less than 5 percent of patients surviving for five years. In 2008, approximately 215,000 people were newly diagnosed with lung cancer, and 162,000 died of the disease.
In addition to Tarceva, Avastin (bevacizumab) is another targeted treatment for NSCLC. Other treatment options include surgery, radiation treatment, and chemotherapy.
Although VeriStrat is currently available only in the US, Biodesix is validating the test in an ongoing phase III trial in Italy. "It is the company’s intent to expand into EU markets in the future," Beresford noted. "At that time we would evaluate the most appropriate regulatory pathway forward."