Tuesday, May 14, 2013

FDA Approves First Companion Diagnostic for Lung Cancer

May 14, 2013
The US Food and Drug Administration today announced the approval of the cobas EGFR Mutation Test, a companion diagnostic for the cancer drug erlotinib (Tarceva). This is the first FDA-approved companion diagnostic that can detect epidermal growth factor receptor (EGFR) gene mutations, which are present in approximately 10% of non–small cell lung cancers (NSCLCs).
The approval of this test comes at the same time as an expanded indication for erlotinib. The FDA has also announced a labeling change for erlotinib, and the drug is now indicated for first-line use in patients with metastasized NSCLC that tests positive for EGRF mutations. Until now, the official indication was second- or third-line use in advanced NSCLC.
"The approval of the cobas EGFR Mutation Test will allow physicians to identify non–small cell lung cancer patients who are candidates for receiving Tarceva as first-line therapy," said Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA's Center for Devices and Radiological Health, in a statement. "Companion diagnostics play an important role in determining which therapies are the safest and most effective for a particular patient."
The safety and effectiveness of the cobas EGFR Mutation Test was established with clinical data showing progression-free survival in NSCLC patients with specific types of EGFR mutations (exon 19 deletions or exon 21 L858R substitution mutations) for 10.4 months when they received erlotinib treatment, compared with 5.4 months for those who received standard therapy.
In the United States, erlotinib is currently the only drug available for use in EGFR-positive NSCLC, although elsewhere in the world, another similar drug is widely used: gefitinib (Iressa). A third drug in this class of EGFR tyrosine kinase inhibitors (TKIs), afatanib (Boehringer Ingelheim), is close to approval, with an FDA decision expected in July 2013. Afatanib will also have its own companion diagnostic test ( Therascreen EGFR PCR Kit, from Qiagen).
Using an EGFR TKI in the first-line treatment of EGFR-mutated NSCLC is recommended by several clinical guidelines, including the American Society of Clinical Oncology.
Patient outcomes are significantly better when compared with chemotherapy, so much so that it "would be a tragedy not to use" an EGFR inhibitor in an EGFR-positive patients, according to one expert in the field, Edward Kim, MD, PhD, assistant professor of medicine and director of clinical operations at the University of Texas M.D. Anderson Cancer Center in Houston. To not know whether the tumor is mutation-positive is not acceptable anymore, he added.
However, testing for mutations is not yet routine, and there are difficulties with obtaining lung cancer samples of sufficient size and quality, as well as disagreement over which is the best method for obtaining such samples, as recently reported by Medscape Medical News. In addition, there are issues with the costs of such testing, as outlined in a comment from a surgeon is response to that article.
The cobas EGFR Mutation Test is manufactured by the Roche Molecular Systems. Erlotinib is co-marketed by California-based Genentech, a member of the Roche Group and OSI Pharmaceuticals.
 
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