Tiny Seryx has a big new partner in LabCorp.
Late last week, the largest clinical reference laboratory in the country said it will soon begin offering the private Canadian company's CYP450 data-interpreting service to its physician clients.
LabCorp has only recently taken a non-exclusive license to Seryx' Signature Genetics interpretation service and it is still deciding how it might offer the service to physicians ordering the lab's PCR-based or AmpliChip-based CYP450 tests, a spokesperson for the reference lab told Pharmacogenomics Reporter this week. The service should be available by mid-February, according to JP Morello, Seryx' senior scientific R&D executive.
No one knows yet how clinicians will inject pharmacogenomic data into drug-prescription decisions, especially for complicated situations in which genetics, drug interactions, and more familiar clinical factors conspire to affect drug response, but Seryx thinks it can help. The firm has staked out the ground between CYP450 genetic testing and the clinic by processing CYP genotyping data into drug dosage recommendations, with the hope that it can sell to a still-undefined market, and LabCorp's nod appears to give the firm's approach a little more heft.
"LabCorp will go into the physician's office offering [a CYP450] test, and at the same time offering our interpretation report as a sort of companion," said Morello. Whether genetic testing and interpretation will be bundled together or offered in another specially priced form is "being worked out" in negotiations, he said. "The need of the market is going to dictate how this is going to be structured."
"LabCorp will go into the physician's office offering the test, and at the same time offering our interpretation report as a sort of companion."
Lab 21, a United Kingdom-based reference laboratory, is currently in discussions with Seryx concerning a similar deal, Morello said.
At present, Seryx only provides interpretation for the interaction of CYP450 genes 2D6, 2C9, and 2C19 with a list of 45 drugs that it plans to expand, said Morello. The company also intends to apply its service to include additional genes, starting with a project under development to interpret data related to the gene VKOR1, which the firm hopes will guide prescription of the popular blood-thinning drug warfarin, Morello said. Also, the company has "identified a short list of potentially interesting genes now it's just a matter of going through it," he said.
Neither LabCorp nor Seryx will disclose the price of a single interpretation report, as obtained through their collaboration, but Seryx sells reports to individual patients through MedicAlert for $265 to $590, depending on the number of genes and which drugs the report takes into account. A one-gene test costs $265, a two-gene test generally costs $390, and a three-gene test costs $590, according to Morello.
In its arrangement with LabCorp, physicians will send the diagnostic lab a buccal swab, the lab will genotype it for the appropriate CYP450 genes, and it will send that information to Seryx. From there, Seryx will return to LabCorp a report containing dosage recommendations using its Signature Knowledge Base database, which consists of data culled from the scientific literature concerning CYP450 genes, drug metabolism rates, and drug dosages. LabCorp will then forward the report to the physician.
"So sometimes you get a dosage adjustment suggested by the authors saying, 'Reduce the dose by half,' or sometimes it's a study on drug-drug interaction, and again you'll get dosage adjustments or some [other] consideration," Morello said.
Representatives of both Seryx and LabCorp declined to disclose how many reports the two companies expect to sell annually. Both also declined to disclose the financial terms and the duration of the license.
Of the drugs for which Seryx will produce a report, the psychotherapeutics category, such as anti-psychotics and antidepressants, is "by far the largest," said Morello. The other categories represented in that list include cardiovascular and diabetic drugs, he said.
Despite LabCorp's interest in Seryx' service, the diagnostic testing giant seems to expect slow demand from CYP450 testing, at least in the near term, and there is no guarantee that clinicians will make use of the newly available interpretation, especially if they are uninitiated to pharmacogenomics.
Richard Balon a professor of psychiatry at Wayne State University in Detroit, admits that he is not very familiar with the use of pharmacogenomics in psychiatry, and he has not been convinced that a data interpretation service will encourage much clinical genotyping to inform prescriptions. "I'm not sure how helpful it's going to be in routine clinical practice, because I don't think you're really concerned about [drug metabolism rates] much, unless you have a treatment-resistant patient or something like that, where you want to know, 'Is this because this person is metabolizing this so fast?" he said.
Adverse events related to psychiatric drugs occur "fairly frequently," said Balon. But because serious adverse events are rare, Balon is more likely to prescribe a drug and watch what happens, he said. "Ninety-nine-point-nine percent of the time they're not life-threatening side effects, so I'm not going to do it in the era where everyone is trying to cut costs … who is going to pay for that" at the start of treatment? he asked.
In a situation in which a patient is taking several potentially interacting drugs, such a test and its recommendations become more attractive, Balon said. But "the likelihood in my case remains low," he added.
In some situations the need for pharmacogenomic information is greater, but it may not become a common feature of clinical practice, said Alan Schatzberg, a professor and chair of psychiatry and behavioral sciences at Stanford University. "In an average person on a non-tricyclic [antidepressant] who is expected to be a good drug metabolizer there isn't any particular gain from that," said Schatzberg. "This test would've probably been much more useful in the days when we used tricyclics, because there was a greater risk for cardiotoxicity," he said. "But it could be useful in special situations," such as with patients who show no response at all, or who cannot tolerate a certain drug at all, he said.
Asked whether Seryx should focus its efforts largely on complex prescribing situations, Schatzberg said, "I believe so. In a patient who is taking a lot of 2D6 inhibitors or is on 2D6-metabolized drugs, like beta-blockers, there may be some importance in looking at 2D6," he said. A situation like that becomes more common in the elderly, he added.
Chris Womack ([email protected])