After using its Oxford Genome Anatomy Project database to identify 25 potential protein biomarkers for colorectal cancer, Oxford Genome Sciences announced this week that it has partnered with Biosite to develop a diagnostic test for the cancer.
The test will focus initially on detecting colorectal cancer relapse, said Gunars Valkirs, senior vice president in charge of discovery at Biosite. If that test is successful, the companies may then move to apply it as a colorectal screening test for the general population.
In October 2004, OGeS launched its OGAP database, a genome-based protein database that contains about a million peptides sequenced from 50 different tissues and 58 diseases (see ProteoMonitor 10/8/2004). Researchers at OGeS selectively mined the OGAP database to identify proteins that were specific to colorectal cancer. The 25 proteins identified are either secreted, on the cell surface, or from the blood, said Christian Rohlff, CEO of OGeS.
"Most people do differential analysis between different disease and control sets and find a test panel of proteins, and then they have to do a lot more validation," said Rohlff. "The key thing that makes a difference for us is that we have the reference database, which allows us to immediately check for the specificity [of potential biomarkers] across cancers. That's a big time-saving tool for us. We use the database as an in silico tool to look for which are the most specific biomarkers in the panel."
Another advantage of using the database is that it results in a panel composed of proteins that come from different sources, including blood, tissues, and plasma membranes, Rohlff added.
"To rely solely on blood is limiting," he said. "Having support from tissues and the plasma membrane really builds a better panel, and gives us more confidence."
For its part, Biosite brings to the deal its phage display-based technology for developing antibodies at a low cost.
"Our antibody capability … enables us to do studies where we analyze 50 to 100 biomarkers in a very cost-effective fashion," said Valkirs. "Without that, the studies would be cost prohibitive."
In addition, Biosite has expertise in developing multi-marker panels. The company uses an internally developed technology that finds the best algorithm for combining markers so that the discrimination between diseased and normal populations is maximized.
"When you combine multiple markers, you get a much better diagnostic result than for any single marker," said Valkirs. "In applications such as acute coronary syndrome and stroke, we have pioneered the use of multiple markers."
Valkirs said Biosite is currently searching for a source of clinical samples on which to test the biomarkers that OGeS has identified for colorectal cancer.
"If we don't find a source of clinical samples, we will launch our own prospective source," he said. "One way or another, I can guarantee you we will get samples. That's not going to be the problem that can't be solved."
Valkirs estimated that it will take about three years to develop an assay for colorectal cancer, and to bring it through the regulatory process.
Currently, relapse of colorectal cancer is tested by colonoscopy, which is an invasive procedure. Relapse occurs in about 30 to 40 percent of colorectal cancer patients within about 18 months of primary diagnosis, according to Biosite.
Both Valkirs and Rohlff said they do not know of any other company that is working on developing a diagnostic for colorectal cancer.
"There's a test called CEA that's used to monitor tumor growth, but it's not useful for either relapse [testing] or screening the general population," said Valkirs. "Aside from that, there's nothing else out there. Nothing has been submitted to the [US Food and Drug Administration], and nothing is in development."
Biosite has already launched a multiple-marker-based test for stroke in Europe, and the company is planning on launching a multiple-marker-based test for acute coronary syndrome in Europe this year. Both tests are currently undergoing review by the FDA.
In total, Biosite sells about $300 million worth of products annually, Valkirs said. About $190 million comes from a test for congestive heart failure based on a single peptide biomarker called BNP. That test was released in 2000. Of the remaining $110 million, most comes from a toxicology product line, and a small amount comes from a microbiology compound line, Valkirs said.
Aside from its collaboration with OGeS, Biosite has about 30 other collaborations with pharmaceutical, proteomic, and genomic companies, Valkirs said. Some of the largest collaborations are with Eli Lilly, Amgen, and Novartis.
Some collaborations have led to Biosite developing diagnostics based on therapeutic targets developed by pharmaceutical companies, Valkirs said.
"Our antibody technology gives us a trading chip so that we get diagnostic rights to targets that we would never have access to otherwise," he said. "We're not involved in the development of therapeutics. We have not interest in playing in that field, so we're not a threat to [pharma companies]. We're a provider of a key service. In return for that, we get diagnostic rights to something they normally would have sat on."
Valkirs said that Biosite had been talking to OGeS on and off for about five years before the recent collaboration was formed.
"This isn't a new conversation. We were talking to them even before they spun the company out [from Oxford GlycoSciences] as a private entity," he said (see ProteoMonitor 9/24/2004).
In picking a partner for its colorectal cancer initiative, it was important for Biosite to collaborate with a lab that had solid intellectual property, Valkirs said.
"I believe the IP will be important, and OGeS was a perfect fit for that," he said.
Aside from collaborating on colorectal cancer, OGeS and Biosite may also work together to develop diagnostics for other cancers as well, Valkirs said.
Financial terms of the current collaboration were not disclosed.
— Tien-Shun Lee ([email protected])