NEW YORK (GenomeWeb) ─ Response Genetics entered the next-generation sequencing-based diagnostics market this week with the launch of a non-small cell lung cancer panel proprietary to the Knight Diagnostic Laboratories at Oregon Health & Science University.
The test, according to OHSU's website, operates on an Ion Torrent PGM platform and gauges a number of genetic alterations known to impact lung cancer patients' response to different treatments, as well as markers that are being studied in investigational drug trials.
Among the genes analyzed by the panel are EGFR, HER2, and BRAF, mutations which are associated with patients' ability to respond well to Tarceva (erlotinib), Tykerb (lapatinib), and Zelboraf (vemurafenib); DDR2 mutations, which according to some studies, make squamous cell lung cancer patients sensitive to Sprycel (dasatinib); and KRAS mutations associated with limited response to Tarceva (erlotinib). Additionally, the test will analyze a number of genes being explored in the lung cancer setting, such as ALK, NRAS, HRAS, and AKT1.
The company believes that because OHSU's test gauges specific actionable genetic alterations, it will be a better option for doctors and patients than diagnostics that gauge hotspot regions of a gene where mutations and other abnormal changes are more likely to occur.
"For us, it is important that we select something that is curated, carefully thought out, rather than sort of a shotgun approach, with a gazillion genes," Stephanie Astrow, VP of research and development at Response Genetics, told PGx Reporter. "We wanted something where the test made sense. That was one appeal of [OHSU's] panel."
By analyzing the entire coding region of the genes of interest instead of just the hot spot regions, OHSU's test can potentially pick up on alterations that impact treatment response and that might have been otherwise missed. "We didn't just want to do a hotspot panel. We wanted to have something that had full gene interrogation," Astrow said. "What we learned from the KRAS story was that this was going to be increasingly important."
Recently, published studies have suggested that metastatic colorectal cancer patients with RAS mutations in regions other than the standard exon 2 region also lack benefit from anti-EGFR treatments. In a study published in the Journal of Clinical Oncology earlier this month, researchers from Amgen and other institutions reported that when they considered metastatic colorectal cancer patients with not just wild-type KRAS mutations in exon 2 but also wild-type KRAS and NRAS mutations occurring in exons 2, 3, and 4, they experienced a significant overall survival advantage from anti-EGFR therapies versus anti-VEGF therapies. The survival benefit from anti-EGFR therapies was much better, researchers found, when they considered wild-type RAS patients as a whole versus just patients with wild-type KRAS exon 2 tumors.
"For the longest time, the region of KRAS that everyone was looking at was exon 2," Astrow said. But studies have shown that "there are important mutations in other codons that lie in exon 3 and exon 4 and they had predictive power as to resistance to EGFR targeted therapies. So, if you were focused on exon 2 as your hotspot then you miss those other regions."
The NGS-based lung cancer diagnostic will be offered as part of Response Genetics' Academic Profile suite of tests, which provides doctors various options, including FISH and PCR-based platforms. It's up to Response Genetics' physician customers to decide how deeply they want to test a particular patient's tumor.
"Most of our physicians know what they want," Astrow said. "They're not at all confused about how extensively a work up they want on their patients … But if someone has questions, we're happy to work with them … and advise them not just on what's the best test but what a test means in terms of patient management."
Response Genetics said it will begin offering the NGS lung cancer test to its customers immediately. According to Astrow, the company's sales force will incorporate the NGS test into its marketing efforts, but, overall, the sales strategy won't change. Response calls on pathologists and oncologists at community practices and large academic centers. The NGS test is "another option to offer particularly to those physicians interested in the technology or in these genes that are a little bit more in the experimental realm," Astrow said.
In terms of reimbursement, the company will use a combination of Tier 1 analyte-specific CPT codes and miscellaneous CPT codes to bill payors for the NGS lung cancer test. "The reimbursable genes are billed," Astrow said. "The fact that the test is next-gen versus another technology doesn't really have too much of an impact [on payment]."
Similarly, Medicare reimbursement is also based on the markers being gauged, not so much the platform technology, Eric Chen, VP of business development at Response Genetics, said. "Next-gen is somewhat synonymous with more markers or panels, but from a Medicare point of view they only care what markers are being tested," he explained.
Furthermore, Response Genetics doesn't bill patients if any portion of the test is not paid for. "If we're denied reimbursement from an insurance company, we don't try to go after the patient for the balance," Astrow added.
In addition to its offerings for lung cancer, Response Genetics currently markets genetic tests for gastrointestinal, gastric, thyroid, and breast cancers, as well as a panel test for solid tumors that analyzes 37 genes. The company has plans to eventually roll out NGS-based testing for these other tumor types.