In addition to launching its ProScan test for prostate cancer, CombiMatrix (Mukilteo, Washington) also reaffirmed its regulatory stance in offering its HerScan as a laboratory-developed test (LDT) for breast cancer in response to a citizen petition Genentech (South San Francisco, California) had filed with FDA earlier this month.

CombiMatrix said that expanded study results on its HerScan array comparative genomic hybridization (CGH) test demonstrated 97% concordance with fluorescent in situ hybridization (FISH) enumeration of the Her2 gene locus. The evaluation was based on 100 additional breast cancer cases and was presented this month at the annual San Antonio Breast Cancer Symposia.

"These data also validate our stance that a comprehensive understanding of the chromosomal makeup of a cancer cell is indispensable, and has always been the hallmark of prudent [LDTs] for cancer diagnostics," said president/CEO Amit Kumar, PhD.

Genentech recently filed a petition asking the FDA to re-evaluate its regulation of LDTs, including CombiMatrix' HerScan test. In its Dec. 8 filing, it said that marketing claims made by several laboratory test developers suggest the agency's "inconsistency" in regulating LDTs has led to an increase in the number of tests that are not adequately validated. The biotech company named the HerScan from CombiMatrix as one such test.

"While we agree with Genentech on the key points in the petition, we were disappointed that Genentech did not contact us or evaluate our validation data before mentioning our test in their petition," Kumar. "The FDA in its guidance documents has clearly stated that cytogenetic tests, of which HerScan is one, are appropriate for operation as LDTs."

Kumar said the FDA issued CombiMatrix a letter in October 2006 stating that its tests can be run as LDTs.

"This whole area of genetics is brand-new and it's emerging and there [are] concerns about how these things are going to be regulated," Kumar told MDD. "We have this tremendous amount of support from FDA ... that's a very powerful support from the leading regulatory agency in the world regarding our tests and how we're running them and what kind of benefit they have to patients."

– Amanda Pedersen