British Journal of Dermatology publishes data on DermTech's new genomic assay for melanoma

Feb 7 2011

DermTech International, Inc., a biotechnology company dedicated to bringing genomic medicine to dermatologists, today announced that the discovery data on its new genomic assay for melanoma have been published in the British Journal of Dermatology.  The test is based on the EGIR™ technology (Epidermal Genetic Information Retrieval) that non-invasively collects cells from the skin's surface using a custom adhesive.  Details from the paper titled "Non-invasive Genomic Detection of Melanoma" show that the test is 100% sensitive in identifying melanoma.  

The EGIR-based technology assessed pigmented skin lesions thought to be suspicious for melanoma and identified all the lesions containing either in situ (early stage) or invasive disease correctly 100% of the time.  The test registers 88% specificity (12% false positives).  These results are more accurate than any currently available melanoma detection tool.  The study was performed at 18 sites across the United States.

"Once it becomes available, this new 'tape stripping' technology will allow us to non-invasively evaluate lesions which might not rise to the level of clinical suspicion that would prompt one to perform a biopsy, but which nonetheless, might harbor melanoma," said Mitchell Kline, MD, Clinical Assistant Professor of Dermatology, New York Presbyterian-Weill Cornell Medical School.  "I believe that this genomic-based approach will allow dermatologists to more fully assess patients in advance of a biopsy and the test's very low false positive rate should translate to a reduced number of required excisions.  This is a technology I expect will have advantages for patients and the healthcare system."

The paper shows that the EGIR method, which uses adhesive to harvest cells from the skin, identified genes that were differentially expressed in melanomas versus normal skin and nevi.  Class prediction modeling identified a 17-gene biomarker that detects both in situ and invasive disease.  As part of the year-long multi-center study, 202 total lesional samples were collected (samples included superficial spreading melanoma, nodular melanoma and lentigo maligna, often misdiagnosed as solar lentigo, a sun spot).  

"Worldwide, the incidence rate of melanoma is climbing faster than any other cancer," said Daniel M. Siegel, MD, incoming President-Elect of the American Academy of Dermatology.  "Accurate detection remains the most significant challenge that dermatologists face daily in their practices.  Early detection and full excision with proper margins is the only cure for this disease and dermatologists will benefit from tools that help them identify all instances of melanoma.  The EGIR technology in development appears to be a major step in this direction."

The current standard of care, an invasive biopsy followed by histopathologic evaluation, typically reveals the presence of melanoma just 3.5-5% of the time. The marked increase in specificity of the genomic test may better identify which of the patient's lesions contain melanoma, effectively helping to direct biopsies.  

Many experts believe that, in addition to limiting invasive procedures, the genomic test may be more accurate than today's detection methods. In one case, as reported in the paper, a lesion that was read to be benign by standard review of histopathology was called positive for melanoma using the biomarker-based test.  The patient's tissue was then serial sectioned and re-examined by the pathologists, at which time invasive melanoma was diagnosed.

DermTech is now translating these discovery data onto a quantitative PCR platform. Preliminary results suggest the feasibility of using this 17-gene biomarker in a clinical laboratory setting.  Additional sample collection activities are ongoing in the US, Australia and Europe.

"If these findings are confirmed in an expanded clinical validation study, it would establish the EGIR-based assay as a more accurate and cost effective alternative to the currently available tools for melanoma detection," said George Schwartz, CEO, DermTech.