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Medco to Evaluate Clinical Utility of AssureRx's PGx Test in Guiding Psychiatric Treatment


By Turna Ray

Reimbursement and adoption prospects for AssureRx's GeneSightRx test will likely receive a boost if a Medco Research Institute pilot study is able to show that the pharmacogenetic test is clinically useful in helping doctors choose which psychotropic medications are best suited for their patients.

In a pilot project known as PGx-Directed Prescribing of Psychotropic Medications, or PREDICT PSYMEDS, the pharmacy benefits manager will study whether its members are more willing to take â€" and stick with â€" antidepressant and antipsychotic drugs prescribed to them based on a genetic test that suggests they are most likely to benefit from such treatment. Medco will also investigate whether doctors are willing to prescribe the testing to their patients and if they factor in genetic data in determining which drugs their patients should take.

Medco will recruit 2,000 of its members who are currently taking one or multiple antidepressant and antipsychotic medications approved by the US Food and Drug Administration and who switched or added psychotropic medications to their treatment regimen in the past 90-day period. The PBM will begin recruiting patients for the study in the third quarter of this year and enrollment is expected to last six months. Researchers plan to observe patients in the study for one year, slating the project for completion by mid-2013.

After patients receive a treatment recommendation based on their GeneSightRx results, Medco researchers will track them over the next 12 months to see if they adhere to that prescription, whether they switch treatments, or whether they add additional drugs to their regimen. Medical endpoints of the PREDICT PSYMEDS pilot include adverse event diagnoses and hospital and clinical utilization.

"PREDICT PSYMEDS is real-world observational pilot with the only intervention being the introduction of the GeneSightRx test into clinical practice under the oversight of the patients' prescribing physician," Bryan Dechario, Medco Research Institute's senior director, told PGx Reporter.

For each patient who agrees to genetic testing as part of the study, a cheek swab sample will be genotyped at AssureRx's CLIA laboratory. The lab report will be sent to the patient's prescribing physician and to the Medco Research Institute. After this point, Medco will track the participant’s pharmacy and medical claims for one year. Outcomes of patients who received genetic testing will be compared to outcomes of matched controls from Medco’s longitudinal pharmacy and medical claims databases.

While Medco will track utilization within its system to assess which patients are filling their prescriptions, the PBM will not conduct additional follow-up to ensure whether study participants have really taken their medications.

"Utilizing additional follow-up assessments could alter the standard of care and medical decisions that both the patient and their physician would naturally make during the course of treatment, which could bias the results [and therefore] limit their applicability to current clinical practice," Dechario said. "While it is true that a patient who fills [a prescription] may not take it, it is less likely that a patient who repeatedly fills prescriptions month after month is not taking his or her medication."

He noted that multiple claims-based research studies on adherence, conducted by Medco and external researchers, have shown that "patients who fill their prescriptions regularly and therefore have high medicine possession ratios have better clinical outcomes."

In PREDICT PSYMEDS, Medco will also track physician behavior to assess which doctors choose to test their patients and the extent to which doctors consider patient gene-drug response data in making a treatment decision. "We know from our commercial clinical programs that other specialists like cardiologists and oncologists do use this type of pharmacogenetic data to inform prescribing decisions," Dechario said. "The PREDICT PSYMEDS pilot will be our first time implementing a personalized medicine test into psychiatric practice, and as such we will learn whether psychiatrists [behave] similarly or differently compared to other specialists."

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Last year, Medco presented data at the American Society for Human Genetics annual meeting showing that when doctors and their patients were educated about PGx-guided dosing for warfarin and tamoxifen, about half of more than 40,000 patients identified for the study received testing (PGx Reporter 11/10/2010).

The GeneSightRx panel tests for five gene markers: CYP1A2, CYP2D6, CYP2C19, the serotonin transporter gene SLC6A4, and the serotonin 2A receptor gene 5HTR2A. In past studies, these variants have been associated with how patients respond to psychotropic medications. AssureRx is currently selling GeneSightRx as a laboratory-developed test.

"Genetic variations are important considerations for patients taking psychotropic medications, leading to differences in how patients tolerate and respond to antidepressants and antipsychotics," said Felix Frueh, president of Medco Research Institute, in a statement. "The PREDICT PSYMEDS pilot is designed to demonstrate how pharmacogenetic-guided prescribing can add precision to these therapies. We hope that we can demonstrate that using such technology can help improve patient drug response and reduce side effects, and result in cost savings to payors."

Medco will track cost data in the PREDICT PSYMEDS study, considering both the pharmacy and medical spending perspectives. Dechario said Medco expects to see a "significant" cost-effectiveness impact on both measures when GeneSightRx is used to guide therapy decisions. "Patients with conditions targeted by the pilot enrollment criteria, like treatment-resistant depression, cycle through multiple medications, increasing drug wastage and requiring multiple clinical visits to their physicians' office," he explained.

Although this is the first study Medco is conducting to gauge the impact of genetic testing in the psychiatric care setting, the PBM last year began research to validate gene markers associated with patient response to antipsychotic drugs. In August 2010, the Medco Research Institute began collaborating with SureGene on the Relative Effectiveness of Schizophrenia Therapy, or REST, study, to investigate whether genetic variations in the SULT4A1 gene can be used to administer antipsychotic drugs to patients most likely to respond to them (PGx Reporter 08/25/2010). The study will also evaluate the cost effectiveness of using SULT4A1 polymorphisms routinely in the care of mental health patients.

Ultimately if the PREDICT PSYMEDS study shows that adopting GeneSightRx in psychiatric care improves patient outcomes in a cost-effective way, this test could be included in Medco's commercial PGx program, which so far offers clients genetic testing services that gauge patient response to warfarin; tamoxifen; the anti-platelet drug Plavix (Sanofi-Aventis/Bristol-Myers Squibb); the leukemia drugs Gleevec (Novartis), Sprycel (BMS), and Tasigna (Novartis); and the HIV treatments Selzentry (Pfizer) and Ziagen (GlaxoSmithKline) (PGx Reporter 05/26/2010).

"The goal of all pilots conducted within the Medco Research Institute is to demonstrate a significant improvement in patient care, which can be operationally implemented in a cost-effective way by Medco for Medco clients â€" the payors," Dechario said. "If the current pilot [involving GeneSightRx] meets this goal it is likely to become a PGx program offering for Medco clients, similar to the previous translation of our Medco-Mayo warfarin study into our current warfarin PGx commercial program."

If the pilot study is successful, and GeneSightRx is offered through Medco's commercial PGx testing services, then it will open up a broader customer base for AssureRx and pave an easier path in terms of reimbursement when its test is administered within the PBM system. AssureRx could not respond to questions about the current reimbursement level and adoption of GeneSightRx ahead of press time.

Diamond Healthcare, a Richmond, Va.-based behavioral health and chemical dependency services company that partners with hospitals and academic medical centers, began rolling out GeneSightRx last year in 10 of its nationwide behavioral health units. Diamond said that it planned over this year and next to make the test available within its 30-state network (PGx Reporter 09/29/2010).

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