NEW YORK (GenomeWeb) — Janssen Diagnostics said last week that it is now offering research services on its Cellsearch system for circulating tumor cell preparation in conjunction with Asuragen's SuraSeq next-generation sequencing cancer panels.
The Cellsearch system is a semi-automatic platform to capture and quantify circulating tumor cells from blood samples. Janssen Diagnostics, which is part of Johnson & Johnson's pharmaceutical business and is based in Raritan, NJ, and Beerse, Belgium, sells the system and offers research services on the platform. The Cellsearch platform has been cleared by the US Food and Drug Administration for monitoring metastatic breast cancer, metastatic colorectal cancer, and metastatic prostate cancer patients.
Up until now, the system, originally sold by Veridex before it became part of Janssen Diagnostics, has been mainly used to determine the number of CTCs in a sample, "but we know that clinicians and researchers are interested in understanding how the cancer cells are evolving," Kristen Hollingsworth, global business leader for oncology at Janssen Diagnostics, told Clinical Sequencing News. After receiving customer requests for next-gen sequencing assays on CTCs, "we found that there was a unique opportunity for us to partner with Asuragen to offer not only the enumeration piece but also the next-gen sequencing piece," she said.
Under the partnership, Janssen Diagnostics will capture CTCs on the Cellsearch system and send the preparation to Asuragen, based in Austin, Texas, which will sequence them using its proprietary SuraSeq cancer panels. The service will have a typical turnaround time of about 10 days.
According to its website, Asuragen offers four predesigned SuraSeq cancer panels. The company developed the panels for the sensitive detection of clinically actionable mutations from limiting DNA quantities, including formalin-fixed paraffin-embedded samples, and launched the first two panels in the spring of 2013.
Janssen Diagnostics chose to partner with Asuragen for its service because the two firms had successfully collaborated in the past on other types of assays, Asuragen had experience with CTCs, and because Asuragen satisfied Janssen in terms of logistics, capacity, and quality standards, said Ron Mazumder, global head of R&D and operations at Janssen Diagnostics. "The idea was to use the strengths of both partners — we have a strength in circulating tumor cells, and they have a strength in next-generation sequencing," he said.
The new service could be applied to any tumor type, but Janssen expects considerable interest from breast and prostate cancer researchers, Hollingsworth said.
Researchers have already begun to couple the Cellsearch system with next-generation sequencing on their own. Last month, for example, a group from the University Foundation in Chieti, Italy, published a study in PLOS One in which they characterized EGFR mutations in Cellsearch CTC preparations from non-small cell lung cancer patients using sequencing on the Roche 454 GS Junior. The combination is "a very sensitive and specific diagnostic tool for EGFR mutation analysis in CTC preparations with potential clinical impact," the authors wrote.
A Janssen spokesperson told CSN that this approach aligns with what the company is doing, but the firm will be able to sequence multiple genes rather than a single one.
Among Janssen's competitors is Cynvenio Biosystems, which in late 2012 launched a service that couples CTC isolation with targeted sequencing using the Ion Torrent AmpliSeq panel. But the Cellsearch system is the only FDA-cleared system for CTC capture and enumeration so far, "so we really have a strong differentiating feature from other competitors out there," Hollingsworth said.
Over time, Janssen might expand the molecular characterization of CTCs beyond gene panels. "As this collaboration expands and we see more demand, we can certainly look at RNA-seq or protein profiling," Mazumder said. "This is one step towards the full characterization [of CTCs]."
The ability to study different types of markers is one feature that differentiates CTC analysis from the analysis of cell-free tumor DNA, he added.
Down the road, coupling CTC preparation with sequencing-based mutation analysis could have applications in diagnostics, for example, to look for secondary mutations that are associated with drug resistance. "We're looking at some possibilities there but nothing has gone into diagnostic development," Mazumder said.
Cancers with many molecular subtypes, such as lung cancer, would be good candidates for diagnostic applications, and Janssen is looking into colorectal cancer as well. "It depends on the convergence of the needs of the drug program, how many circulating tumor cells we can get in any indication, and what the value of the molecular characterization is — those are the criteria we use," he said.