Oxford Gene Technology took another step towards the diagnostics market last week by signing an agreement with researchers at the Wellcome Trust Sanger Institute to develop a multi-syndrome detection test based on the UK firm’s array comparative genome hybridization technology.
The deal represents a new front in OGT’s efforts to put its CGH chips in the hands of UK clinicians, following partnerships with UK-funded healthcare projects like the Oxford Gene Knowledge Park and an internal effort to develop an array CGH diagnostic.
It also enables OGT to follow other array vendors such as Affymetrix in marrying in-house technology with diagnostic content from external sources.
OGT said it will work with molecular cytogeneticists at Sanger to co-develop a commercial diagnostic to be used alongside current prenatal tests. OGT will use its inkjet in situ synthesis platform to make a 60-mer oligonucleotide microarray, while Sanger will contribute clinical knowledge in targeting “the most appropriate syndromes,” OGT said.
According to OGT CEO Mike Evans, OGT plans to develop a syndrome chip that will initially be used for research purposes only until enough information is generated to secure entry into the European clinical market.
“The plan is that OGT will take the product to market within the EU, however as this product would have global relevance we will be exploring options for international partners,” Evans told BioArray News in an e-mail this week.
This is not the first time that the array firm has signaled its intention to enter the clinical market with its CGH technology. OGT has developed syndrome-specific arrays in the past, both internally and with partners. For example, the company has partnered with the Oxford Gene Knowledge Park, a National Health Service-funded think tank, to develop CGH chips for use in UK cytogenetic labs to test for learning disabilities (see BAN 2/14/2006).
And last October, Evans told BioArray News that OGT was alpha-testing its own syndrome chip with input from OGKP and other cytogenetic groups, and said that the array will include content for Prader Willi, DiGeorge, and Cri du Chat syndromes, amongst others (see BAN 10/3/2006).
OGT this week declined to name syndromes that may appear on a prenatal diagnostic.
“As part of the project we will be working within the clinical community to gain consensus on what prenatal syndromes the array should test for,” Evans wrote in the e-mail. “This is at an early stage so we are unable to provide specifics at this time,” he added. Evans also pointed out that the chip developed with OGKP was fundamentally different in that it was designed to be used in a post-natal setting.
“The OGKP work was focused on an array which would test for a broader range of syndromes in a post-natal setting,” he wrote. ”The work with the Sanger will be focused on developing an array format which is targeted at a focused set of syndromes which are appropriate to test for in a pre-natal setting.”
In terms of array CGH screening tools, the only array currently used for prenatal diagnosis is one offered by the cytogenetics lab at Baylor College of Medicine. However, the lab has drawn criticism from companies like CombiMatrix Molecular Diagnostics and Signature Genomic Labs, which offer CGH-based post-natal testing and have stressed that it is too soon to start offering expectant mothers advice based on what many see as a nascent technology (see BAN 4/11/2006).
"More genotype-phenotype associations need to be [made] before [array CGH] can be used in the prenatal arena," CMDX President Mansoor Mohammed told BioArray News last April. "We need to have a wider corpus of data so we can gain appreciation of genotype-phenotype, phenotype-genotype associations.
“We recognize the importance of a validation phase and will ensure that regulatory approval is obtained prior to a product being marketed as [a] diagnostic.”
“A lot more maturity needs to be put into this before it is used [for prenatal analysis]," he said at the time.
Evans told BioArray News this week that OGT will follow all guidelines when it brings to market its array CGH-based prenatal diagnostic. “The OGT-Sanger program contains the intention to include a phase during which the performance of the array-based test will be compared with that of current prenatal diagnostics approaches,” he wrote. “We recognize the importance of a validation phase and will ensure that regulatory approval is obtained prior to a product being marketed as [a] diagnostic,” he added.
Meanwhile, at the Sanger
According to Nigel Carter, a molecular cytogeneticist at the Sanger Institute, the center and OGT will “design the array to screen for major chromosome abnormalities, [including] the common viable trisomies and large imbalances as well as specific microdeletion and microduplication syndromes which have severe outcomes.”
Though the Sanger has never partnered with OGT before, Carter’s lab has been heavily involved in developing both pre- and post-natal diagnostics using in-house designed and manufactured arrays, including a whole-genome tiling path array comprised of 30,000 large insert clones, he told BioArray News.
Over the past year, Carter has also published work using array CGH in diagnosing syndromes such as trisomy 21, Prader-Willi syndrome, and Pelizaeus-Merzbacher disease. He’s also been a co-author on several recent papers investigating copy number variation.
In terms of his goals, Carter said that the Sanger is interested in developing array technology for non-invasive prenatal screening, and that it does not see its relationship with OGT as a one-project deal. Evans similarly said that OGT would “view very positively any further opportunities to collaborate.”