NEW YORK (GenomeWeb) – Following completion of a validation study, German prenatal genetic testing provider LifeCodexx plans to launch a new noninvasive prenatal fetal trisomy test that is based on methylation-specific quantitative PCR.
The new test, called qNIPT, will become available "as soon as possible," LifeCodexx CEO Michael Lutz told GenomeWeb. It will initially only detect fetal trisomy 21 but is expected to cover other fetal trisomies in the future.
LifeCodexx will offer qNIPT as a service out of its Constance laboratory at first and plans to transfer the technology to other laboratories later on, Lutz said, the same model it followed with its existing PrenaTest, which relies on next-generation sequencing and is now offered by a handful of laboratories in Germany and Switzerland.
The new test will replace the most basic version of the PrenaTest, which only detects fetal trisomy 21 and fetal sex and will be discontinued. The other two versions of PrenaTest, which detect fetal trisomies 21, 18 and 13, either with or without sex chromosomal aneuploidies, will remain available for the time being.
LifeCodexx has filed several patent applications around the technology used for qNIPT. The basic approach — which exploits the different methylation profiles of maternal and fetal DNA found in maternal plasma — was first described in a publication in Clinical Chemistry by Dennis Lo's group in 2006 but the company has made many changes that "finally made the concept work," Lutz said. The method is distinct from work published by NIPD Genetics of Cyprus, he added, which several years ago also pursued a methylation-based qPCR approach prior to switching to an NGS-based method.
The main reason for developing the new test was to "come up with something that is proprietary that does not use NGS," Lutz said.
LifeCodexx believes that qNIPT is not covered by Ilumina and Sequenom's 2014 patent pool around noninvasive prenatal testing. The company did take a license to Sequenom's intellectual property prior to commercializing its PrenaTest but will presumably not need such a license for qNIPT.
Illumina and Sequenom, which is now part of Laboratory Corporation of America, have been asserting their IP rights in the NIPT field aggressively. In October, for example, they obtained an injunction against clinical laboratory company Amedes in Germany and its recently launched Fetalis test, which uses technology developed by Roche's Ariosa Diagnostics. They have also sued companies in the UK, Switzerland, Australia, and Poland for patent infringement.
In the meantime, the European Commission has been looking into potential anticompetitive conduct by the two firms regarding their licensing practices.
Replacing an NGS-placed approach, which Lutz said is "still a quite costly method," with its new qPCR-based approach will allow LifeCodexx to offer the new test at a lower price and with faster turnaround time and higher sensitivity.
The current PrenaTest ranges in price from €300 to €400, depending on the version. The price of qNIPT will be lower, but it has not been determined yet and will depend on "how things are going to work out in the diagnostic routine," Lutz said.
A lower price point will likely expand the market for NIPT, which is currently a self-paid test in many European countries. Over the years, LifeCodexx has seen a "clear correlation" between the retail test price for patients and test volumes at its lab, Lutz said, "and we expect similar things to happen with [the new] test."
Also, once in routine use, qNIPT should be able to reach a turnaround time of two to three business days, he said, down from four to six business days for the PrenaTest.
The test also appears to have better sensitivity than the PrenaTest and similar assays, showing in a recent validation study that it can deliver reliable results with a fetal DNA fraction as low as 2.4 percent, a "nice, unexpected outcome," Lutz said. Most other tests require a fetal fraction of at least 4 percent for singleton and at least 8 percent for twin pregnancies, he added.
Finally, LifeCodexx expects it will be easier to transfer the test technology to other laboratories because qPCR platforms are more established than next-generation sequencing, he said. So far, qNIPT has been validated on one, currently undisclosed qPCR platform but the plan is to expand it to others.
LifeCodexx recently completed its validation study for qNIPT, results of which it plans to publish sometime in the future. The study enabled the firm to obtain the CE mark for the PrenaTest BioIT analysis software for use with the new test.
The blinded prospective study involved close to 1,000 maternal blood samples and demonstrated that the qNIPT results were 100 percent concordant with results from the PrenaTest.
LifeCodexx also recently completed a prospective clinical follow-up study for the PrenaTest that involved more than 2,200 patient samples, which showed that the test was 100 percent accurate for fetal trisomy 21 detection. Â Â Â Â