NEW YORK (GenomeWeb) – UK-based diagnostics firm Angle has made strides over the past year in its goal to become the first to bring an unbiased, epitope-independent circulating tumor cell diagnostic through the US Food and Drug Administration, the firm said in a recent update to investors.
Circulating tumor cells have been somewhat overshadowed in recent years by the excitement over tests that, instead, detect circulating cell-free DNA molecules, and early iterations of CTC technologies that failed to demonstrate adequate clinical sensitivities across cancer types didn't do much to stem that tide.
But researchers and commercial firms are now starting to demonstrate that with the right technology to extract and isolate CTCs, analyzing the genomic or other molecular features can have diagnostic value.
Unlike the first FDA-approved CTC capture technology, Menarini-Silicon Biosystems' Cellsearch, Angle's Parsortix uses a patented microfluidic technology with a disposable cassette to capture and harvest CTCs from blood, based not on specific expression markers but on their less-deformable nature and larger size compared to other blood components.
Angle Founder and CEO Andrew Newland said in an interview this week that the firm has now completed most of its internal analytical validation of the system, demonstrating its technical sensitivity, reproducibility, and establishing other metrics of performance.
More importantly, the company announced this month that MD Anderson Cancer Center has signed on to lead the clinical validity study that will support Angle's submission of the system for use in isolating CTCs from metastatic breast cancer patients for downstream analysis at the end of this year.
In the study, MD Anderson will lead evaluation of the primary endpoint — the ability of Parsortix to specifically isolate CTCs from breast cancer patients — and at least one secondary endpoint related to the genomic or molecular analyses of these cells.
"The plan is to submit our package to the FDA by the end of 2017 … for a platform authorization." Newland said.
"The Intended use of the system is to harvest CTCS from the blood of metastatic breast cancer for subsequent analysis … and the multiple downstream analyses — things like qPCR, NGS, FISH, immunostaining — those are the secondary endpoints," he said.
Though the company hasn't announced other participating research centers yet, Newland said that the study will involve six in total.
When it first began discussions with the FDA, Angle intended to seek approval of Parsortix for CTC harvesting across all cancers. However, the regulator said that this would require substantial clinical data on each individual cancer type in question.
Due to the difficulty of collecting that data, Newland said Angle redirected its efforts to getting the platform authorized first in breast cancer, with plans to follow that up with additional submissions extending use to other specific tumor types.
"The plan is to get the platform authorized and then subsequently add cancers with 510(k) clearance," he explained.
In addition to its recently announced progress in seeking FDA approval for Parsortix in breast cancer patients, Angle is also close to completing two 200-patient clinical studies of tests for the diagnosis of ovarian cancer: ANG-001 in Europe and ANG-003 in the United States.
As of this month, patient enrolment is now complete in both, the company said in its update this month, and the results are slated to be unblinded in time for the first data to be reported before the end of this quarter, Newland explained.
In Europe, where the Parsortix instrument is already CE marked, this would support ovarian cancer as the first clinical application for the system, followed by breast cancer when Angle's studies in that setting are complete, he added.
This February, Angle was also selected to work with Europe's Cancer-ID consortium, a pan-European effort to establish standard protocols for the clinical validation of blood-based biomarkers, helping to bring liquid biopsy testing into routine clinical practice. Newland said this week that multiple consortium sites are now up and running with the platform.
Meanwhile, Angle has now analyzed over 30,000 blood samples using Parsortix, doubling what it had achieved by the same time last year, the firm said in its update this month. The overall installed base of Parsortix instruments stands at over 145. Revenue from cassette sales is up over 500 percent from the same time last year, the company added, suggesting growing adoption of the system into routine laboratory practice.
In the wake of studies showing that antibody-based approaches like Cellsearch can miss CTCs that don't conform to a certain phenotype, but are nonetheless clinically relevant, many other firms have now paralleled Angle's technological approach, advancing platforms that use microfluidics, physical filtering systems, centrifugation, and other technologies to extract CTCs regardless of the particular markers they express on their surface.
But Newland argued that Parsortix's focus on disseminated platform development distinguishes it from many others who have adopted a test service model, and that it believes its technology also offers added value in the ease with which it allows the extraction of CTCs for downstream molecular testing, compared, for example, to filter- or membrane-based platforms, or to systems like Epic Sciences'.