By Monica Heger
In the race to develop the first sequencing-based trisomy 21 test, researchers from GATC Biotech subsidiary LifeCodexx said that they have completed a pilot study in 45 patients and plan to start a clinical validation study in 500 patients.
If all goes well, LifeCodexx could launch the test commercially by the end of the year, the company's CEO Michael Lutz told Clinical Sequencing News.
"The plan is to launch before the end of the year, which is ambitious, but if we get all our ducks in a row, then I think we should be able to get there," Lutz said.
The company completed the pilot study on Illumina's Genome Analyzer. However, Lutz said it plans to switch to the HiSeq 2000 for the clinical validation study and for the commercial version of the test in order to drive the cost down. "With the [Genome Analyzer], we'll never be cost competitive," he said. On the HiSeq however, throughput is higher, and samples can be multiplexed.
In the pilot test, which the group plans to publish in a peer reviewed journal, Lutz said that scientists from the two companies, as well as from the Center for Prenatal Diagnosis and Human Genetics in Berlin, sequenced maternal plasma from 45 patients who had received an abnormal ultrasound, and detected trisomy 21 in eight of the fetuses, all of which were confirmed with karyotyping. The test had 100 percent specificity and sensitivity, and did not elicit any false positive or false negative calls, he said.
LifeCodexx is not the only company developing a sequencing-based trisomy 21 test. Sequenom is developing a very similar test, which it plans to launch by the end of the year or early next year (CSN 3/16/2011). Additionally, Stanford University's Stephen Quake has also described a sequencing-based approach to detect Down syndrome and has licensed the IP co-exclusively to Fluidigm and Artemis Health.
LifeCodexx based its test on technology developed by the Chinese University of Hong Kong's Dennis Lo that was described earlier this year in a paper in the British Medical Journal. Sequenom holds an exclusive license to Lo's technology, which it is using as the basis for its own trisomy 21 test.
Lo told Clinical Sequencing News via e-mail that, from a "scientific point of view, I am pleased to see that they state that they have replicated our work." He added, however, that he would like to see the actual data, which has not yet been published, before commenting further.
Lutz acknowledged that the LifeCodexx/GATC method is similar to Sequenom's, but said the tests are not identical. "We have a few things in common, but a few details that we do differently," he said.
He declined to elaborate further, but said that despite the similarities between the two tests, he did not think there would be any patent disputes. "We looked at it seriously. We're well aware of the patent space," he said.
Sequenom declined to comment on the issue. However, in documents it recently filed with the US Securities and Exchange Commission, it expressed some concern about its intellectual property.
Sequenom holds a broad patent for the noninvasive detection of fetal DNA from maternal plasma for diagnoses, but the patent is not specific to sequencing-based diagnostics.
In its 10-K filing, the company wrote that while it believes that the patent "provides us substantial rights with respect to prenatal diagnostic products independent of platform and we are also the licensee of a patent application that contains claims regarding the use of [massively parallel shotgun sequencing] in prenatal diagnostics, we are also aware of other patent applications that contain the same claims and similar claims are owned or controlled by a potential competitor."
Both Sequenom and LifeCodexx are launching their tests as lab-developed tests, although Sequenom also plans to file for premarket approval with the US Food and Drug Administration. Lutz said that LifeCodexx's primary market would be Europe, and it has no plans to launch its test in the US.
He added that it "will be interesting to see how the FDA reacts" to the launch of Sequenom's test, given the agency's recently stated plans to regulate LDTs more stringently.
Lutz said that LifeCodexx researchers are currently recruiting patients from a number of different hospitals in Europe for the clinical validation study, which it is "planning to kick off shortly."
He said the company will also test sample multiplexing, somewhere between a 2-plex and 4-plex. He cited Lo's recent study, in which he tested the multiplexing of two samples and eight samples, and found that multiplexing just two samples yielded better results (IS 1/18/2011).
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