Clinical Data last week debuted a gene-based test that predicts whether patients with follicular non-Hodgkin’s lymphoma will respond to monotherapy with the oncologic Rituxan.
PGxPredict: Rituximab, launched by Clinical Data’s PGx Health division, is a homebrew test that interrogates for the V158F polymorphism in the FCGR3A gene. It is designed to enable oncologists to identify whether a patient is among the 20 percent of individuals who will respond strongly to the drug, made by Genentech and Biogen Idec.
The launch of the test marks an expansion of a deal Clinical Data penned with pharmacy benefits manager PharmaCare last year to study the costs and benefits of using pharmacogenomics-based tests before prescribing the anticoagulant warfarin or the schizophrenia drug clozapine. [see PGx Reporter 09-20-06].
Clinical Data has also begun working closely with health-care stakeholders, including payors and physicians, to figure out how PGxPredict: Rituximab and similar tests can best be integrated into the clinic.
“It’s fair to say our company is wedded to bringing this type of technology to the forefront so physicians and patients are in a good position to make informed choices,” Clinical Data CEO Drew Fromkin said in an interview with Pharmacogenomics Reporter this week.
Rituxan generated $2 billion in sales in 2006, a 13-percent increase over the previous year. Based on these figures, Clinical Data’s diagnostic, selling for $2,500, stands to earn significantly, depending on adoption by payors and physicians.
According to reports, the incidence of NHL is growing worldwide. The disease is the sixth-leading cause of new cancer cases globally, occurring in 5.6 per 100,000 persons. In the US the incidence of NHL is much higher, occurring in 17.1 per 100,000 people.
Approximately 22 percent of all cases have the V158F polymorphism in the FCGR3A gene.
PGxPredict analyzes patients’ DNA for the presence of the V158F polymorphism in the FCGR3A gene. This gene encodes the Fc-gamma IIIa receptor on lymphocytes to which rituximab binds.
In 2006, Innate Pharma granted Clinical Data exclusive rights to develop PGx tests for cytotoxic therapies such as Rituxan based on its intellectual property for variations in the Fc-gamma IIIa receptor gene. The marker may also be applicable to other cytotoxic drugs with this mechanism of action, Fromkin said.
“Published research indicates that this test is predictive for the response to rituximab in over 90 percent of studied patients with non-Hodgkin’s lymphoma,” Innate Pharma said in a statement.
Based on two independent studies of 49 and 87 patients, those with follicular, CD20-positive, B-cell NHL who carried the 158V/V version of the variant in the FCGR3A gene were more likely to respond to rituximab monotherapy than patients with other variants, Clinical Data said in a statement.
In clinical trials, patients with this particular polymorphism continued to respond strongly to rituximab after one year. However, “approximately half of those who do not carry the 158V/V variant may still respond to rituximab monotherapy,” the company noted.
Clinical Data said it plans to launch the test in Europe in the future, but did not elaborate. In the US, the company is offering PGxPredict: Rituximab as a homebrew, CLIA-certified test, and does not plan to seek clearance from the US Food and Drug Administration.
According to Fromkin, over time, as physicians and patients become more familiar with the test, there may be a possibility that information about the product may be added to Rituxan’s label. “We think over time there is a distinct possibility” to update Rituxan’s label with the genetic test information, Fromkin said, adding that the decision would be up to Genentech, Biogen Idec, and the FDA.
“I think it is early in terms of introducing the test [to the market],” said Fromkin. “We want to work with it in the clinic, and of course … our objective is to begin to catalyze the sector with good information through these tests.”
Clinical Data also makes PGxPredict tests for warfarin and clozapine; markets Familion, a genetic test designed to identify mutations in people with inherited cardiac channelopathies such as long QT syndrome and Brugada syndrome; and sells a pharmacogenetic assay that tests for mutations in the thiopurine S-methyl transferase gene.
According to Fromkin and many other industry players, the managed care community is still getting used to the idea of incorporating PGx tests into therapy. To counter this, he said his company is working closely with payors, oncology-related interest groups, and physicians “to figure out how Clinical Data’s technology is going to be integrated into the clinic.”
“If it’s a question of being open-minded to not allowing that test to go to market, and not allowing physicians and patients to have access to this data, well, that’s not something we’re interested in.”
Clinical Data began providing its homebrew tests last year to PharmaCare — the fourth-largest PBM in the US covering more than 30 million members — to identify patients at risk for being improperly dosed for warfarin or for developing a potentially fatal adverse event when on clozapine. With the introduction of PGxPredict: Rituximab, the collaboration will extend to NHL.
“We’re starting to work with PharmaCare’s oncologists and starting to work directly with other oncologists in direct outreach,” Fromkin said.
As part of this strategy, Clinical Data is claiming that incorporating PGx Predict: Rituximab in physicians’ practices could lead to significant health-care savings.
The company is selling the test for $2,500. Meantime, a four-week course of rituximab for NHL costs approximately $12,000. According to Rituxan’s label, the overall response rate to monotherapy is 57 percent at eight weeks with weekly dosing required for patients with relapsed or refractory, low-grade or follicular, CD20-positive B-cell NHL.
Rituxan’s label states that of the patients receiving rituximab for relapsed or refractory, low-grade or follicular NHL, 57 percent receiving four weekly doses and 70 percent receiving eight weekly doses of rituximab reported Grade 3 and 4 adverse events.
“While rituximab has proven to be valuable in the treatment of patients with follicular, CD20-positive NHL, its high cost … and risk of toxicity may make the choice to prescribe or maintain therapy with rituximab a difficult one for physicians and patients, especially with other treatment options available,” Clinical Data said in a statement.
“Rituxin is a good drug in many instances so it’s important for that therapy to be available and taken appropriately,” Fromkin said. “What we’re trying to do is bring a test that will help physicians have a better idea of patients’ response related to Rituxan.”
Clinical Data does not currently have a marketing alliance with Genentech or Biogen Idec for PGxPredict: Rituximab. Instead, it is taking a more independent, grassroots approach to introducing the test by choosing to partner with payors like PharmaCare and reach out to physicians directly.
However, Fromkin said that Clinical Data would be open to sharing data or discussing marketing alliances with pharmaceutical companies if certain objectives are aligned.
“We’ve been very open to suggestions with regard to marketing of the test … [and] we’ve been very open with any company that’s asked [about the test],” Fromkin said. “If they have data or patient information about how the test can be better now or in the future, we’re wide open to that, because that’s what our objective is.
“If it’s a question of being open-minded to not allowing that test to go to market, and not allowing physicians and patients to have access to this data, well, that’s not something we’re interested in,” he added.
“Any type of marketing partnership would have to be cooperative and in sync with our objective to improve outcomes and reduce cost. … In the end the test needs to be marketed by Clinical Data,” said Fromkin.