NEW YORK (GenomeWeb) – Having this week announced the closing of a $30 million Series C funding round, diagnostics firm Epic Sciences plans to prepare its circulating tumor cell analysis platform for future regulatory submissions while continuing to pursue test development both internally and in collaboration with its pharma partners.
The San Diego-based company aims to optimize its CTC system for submission for US Food and Drug Administration 510(k) clearance, President and CEO Murali Prahalad told ProteoMonitor, calling this a "clear area of strategic focus." Prahalad added that Epic also plans to ultimately submit specific companion diagnostics developed on the platform for FDA pre-market approval.
The company also said this week that it has appointed former Life Technologies Chairman and CEO Greg Lucier as chairman of its board.
Founded in 2008 as a spinout from the lab of Scripps Research Institute researcher Peter Kuhn, Epic uses a combination of proteomic, genomic, and morphological analyses to identify and profile CTCs in patient blood. The company aims to develop tests based on these analyses to help guide patient treatment. In particular, Epic has focused much of its efforts to date on companion diagnostic development and, Prahalad said, is currently involved in more than 35 clinical trials with 17 different pharma partners.
Given their extremely low abundance relative to other blood components, one of the most challenging parts of CTC analysis is isolating these cells for investigation. Typically, Prahalad said, researchers have used one of two main approaches – either using antibody-based pulldown of CTCs via characteristic cell surface proteins, or sorting them out based on their size, which typically differs from that of other blood components.
These approaches have struggled, however, due to the heterogeneity of CTCs, Prahalad said.
"Just as cancer is very heterogeneous, so are the CTCs, and there is incredible variability as to the surface protein expression, as well as the size of these cells," he said.
To avoid missing potential CTCs, Epic's approach looks at all the nucleated cells in a sample, Prahalad said. This method involves spinning down the samples to isolate a cell pellet that includes all white blood cells in a sample along with any CTCs, then resuspending this pellet and spreading it across slides in a monolayer. The cells are then stained for up to five proteins of interest, then analyzed using a high-speed imager that can in 15 minutes collect both the protein information and data on around 90 other parameters – most of them morphological.
With this data, "you can with extreme robustness segregate the outliers from the vast pool of normal cells," Prahalad said. "Anything that deviates from that [normal] pattern you can immediately identify as a putative CTC that then a pathologist or oncologist can verify."
In terms of molecular analyses, Epic's platform is currently focused primarily on proteins, with the system providing both expression and localization data. While the system is currently limited to five proteins, Prahalad said the company has "both chemistry and instrument development programs to rapidly expand that number quite broadly." Though, he added, it has found the five-protein capability sufficient for "the vast majority" of its work to date.
Epic's platform also allows researchers – once the CTCs have been identified – to go back and perform four-channel fluorescence in situ hybridization to look at genetic rearrangements. The company is also working to enable RNA FISH on the platform and has also collaborated with academic partners to sequence identified CTCs, allowing for copy number variation analysis, Prahalad said.
This latter work allows researchers to compare the CTCs to primary tumors to "get a sense of clonal drift" and, for instance, help oncologists understand if they are "dealing with a singular disease or … dealing with a disease that has become multiclonal."
While he acknowledged the importance of analyzing primary tumors, Prahalad said that Epic focuses on CTCs with the expectation that these cells will provide a better look at changes in a patient's cancer as the disease progresses and as the patient undergoes different treatments.
"Cancer is an evolving and adapting disease, so we think that the most comprehensive and real-time assessment of a patient's cancer can be obtained by looking at the CTCs," he said. He added that in the case of late stage disease that has spread to multiple locations, there is the question of "how can you meaningfully biopsy patients?"
In its collaborations with pharma, Epic aims to develop both interventional assays for Phase III clinical drug trials and, ultimately, on-label, marketed companion diagnostics for those drugs, Prahalad said, adding that "we're in late-stage discussions with several partners to do just that." The company is working in 12 different types of solid tumors across its 17 pharma partnerships.
Epic is also working internally on diagnostics for diseases including prostate, breast, lung, and bladder cancer. Prahalad said the company aims to take one or two of those programs to clinical trials next year. Epic will likely launch these first as laboratory-developed tests, he said, but added that Epic is "absolutely committed" to taking its platform through FDA 510(k) clearance – a necessity given its companion diagnostic aims.
The announced financing round included new investors RusnanoMedInvest and Arcus Ventures, existing investors Domain Associates, Roche Venture Fund, and Pfizer Venture Investments, as well as undisclosed individual investors.
The round followed a $13 million Series B round in 2012.