Monogram Biosciences this week announced it will launch its HERmark Breast Cancer Assay on July 15.
The CLIA-certified test, which provides a quantitative measurement of HER2 total protein and HER2 homodimer levels, will be available to US physicians through Monogram’s CAP-certified clinical laboratory.
In a statement, Monogram highlighted the accuracy of its assay in determining which breast cancer patients will benefit from treatment with Genentech’s Herceptin over currently available fluorescent in situ hybridization and immunohistochemistry tests. HERmark measures the HER2 protein and HER2 homodimer levels, while conventional methods measure the HER2 gene, Monogram claims.
"Comparisons with local lab results by IHC or FISH suggest significantly larger numbers of discordant results,” Michael Bates, Monogram’s VP of clinical research, said in a statement. “We believe the HERmark Assay measures HER2 total protein and homodimer levels very accurately and will help physicians to make treatment decisions with high confidence."
Indeed, guidance recently issued jointly by the American Society of Clinical Oncology and the College of American Pathologists indicate that approximately 20 percent of HER2 determinations by current testing technologies may be inaccurate.
The two top players in the HER2 breast cancer diagnostics market are currently Dako’s IHC-based HercepTest and the FISH-based PathVysion HER-2 DNA probe kits made by Vysis, which was acquired by Abbott in 2001. Both tests are approved by the US Food and Drug Administration.
This week, Invitrogen also received FDA approval for its SPOT-Light HER2 CISH kit, which is based on chromogenic in situ hybridization, or CISH. Invitrogen claims that its test also offers a number of advantages over currently available HER2 tests based on IHC or FISH (see Snippets, in this issue for more detail).
Monogram estimates that its HERmark assay can accurately reclassify the 20 percent of inaccurate determinations.
The company highlights that HERmark can detect HER2 at levels from 2,500 to over 1 million receptors per cell, which is seven to 10 times more sensitive than IHC.
In clinical trials, Monogram has found HER2 expression and HER2 homodimer levels to be “independent correlates of both time-to-progression and overall survival.”
Results from the HERmark assay are reported to physicians within seven days. The report the physician receives will indicate patients’ HERmark status as "positive", "negative," or "equivocal".
“The boundaries for the equivocal zone represent an upper level above which 95 percent are positive and a lower level below which 95 percent are negative patients,” the company said.