The National Comprehensive Cancer Network now supports MGMT methylation testing in elderly glioblastoma patients to assess the likelihood that they will benefit from temozolomide treatment. This may help spur adoption of MDxHealth's MGMT PredictMDx for Glioblastoma test.
In the latest version of NCCN's guidelines for central nervous system cancers, the group references MGMT methylation as a prognostic marker in patients with certain types of brain tumors. "Oligodendrogliomas frequently exhibit MGMT hypermethylation and low expression levels, which may explain its enhanced chemosensitivity," NCCN states.
NCCN cites studies that have shown that temozolomide-treated patients with MGMT methylation have longer survival than those without methylated MGMT. After surgery, the group recommends that only patients older than 70 years who are positive for MGMT promoter methylation should receive adjuvant treatment with temozolomide.
MDxHealth CEO Jan Groen said in a statement that getting NCCN's nod for gauging MGMT methylation status in glioblastoma patients will spur oncologists to use the MGMT PredictMDx for Glioblastoma test more readily to guide treatment strategies for patients with brain cancer.
MDxHealth is developing MGMT PredictMDx for Glioblastoma as a tool that doctors can use to gauge if brain cancer patients are likely to respond to alkylating agents, drugs commonly used to treat the disease. Studies suggest that patients with the methylated form of the MGMT gene have a better response to alkylating drugs compared to those with the unmethylated form of the gene.
One recently published study in the Journal of Clinical Oncology looked at whether MGMT methylation status in newly diagnosed glioblastoma patients impacted their response to temozolomide. Researchers led by Mark Gilbert from MD Anderson Cancer Center randomized more than 800 patients to receive either temozolomide or dose dense temozolomide. Patients' MGMT methylation status was determined using the MDxHealth test.
In this study, Gilbert and colleagues found no statistically significant differences in median overall survival or median progression-free survival between those treated with temozolomide and dose dense temozolomide. "Efficacy did not differ by methylation status," the study authors wrote in the abstract.
However, when the researchers stratified based on MGMT methylation status, the test was able to predict best responders regardless of the type of treatment. Glioblastoma patients with methylated MGMT experienced median overall survival of 21.2 months compared to 14 months for those with unmethylated MGMT. Median progression-free survival for those with methylated MGMT was 8.7 months compared to 5.7 months for those with the unmethylated form of the gene.
"This study did not demonstrate improved efficacy for dose dense temozolomide for newly diagnosed glioblastoma [patients], regardless of methylation status," Gilbert and colleagues wrote. "However, it did confirm the prognostic significance of MGMT methylation."
Earlier this year, Merck's 500-patient Phase III trial failed to show a survival advantage for patients treated with the investigational agent cilengitide in combination with temozolomide and radiotherapy compared to just temozolomide and radiotherapy. In the study, researchers used MDxHealth's MGMT test to determine methylation status of patients and gauge if this influenced their outcomes, but they found no such activity (PGx Reporter 6/5/2013) Despite this setback, MDxHealth has ongoing partnerships with a number of drug developers for the MGMT test.
MDxHealth has also received a new Tier 1 CPT code from the American Medical Association for its PredictMDx Glioblastoma test (81287), the company announced. CMS recently released national payment limits for a number of molecular diagnostics described by Tier 1 CPT codes, however MGMT methylation testing was not among the priced codes (PGx Reporter 10/2/2013).
The company has its European headquarters in Herstal, Belgium and is based in the US out of Irvine, California. As such, its Medicare contractor is Noridian.