Novel Interventions in Methotrexate Boosts Levels of Effectiveness (NIMBLE)

The Medco Research Institute® and Exagen Diagnostics, Inc.LLC – a specialty diagnostics laboratory have started a joint pilot program called NIMBLE [Novel Interventions in Methotrexate Boosts Levels of Effectiveness] designed to help physicians optimize the effectiveness of low-dose methotrexate therapy for patients who suffer from rheumatoid arthritis (RA).

An estimated 1.3 million adults suffer from RA in the United States, many of whom are treated with low-dose methotrexate (MTX). MTX is safe, relatively low cost and highly effective; however, it is difficult to determine the optimal dose for individual patients due to the highly variable absorption, excretion and metabolism rates for each patient. Historically, physicians have depended solely on clinical signs and patient symptoms to evaluate the effectiveness of MTX therapy, which do not always indicate how changes to the treatment therapy might benefit the patient. In many cases, if a patient does not respond to MTX therapy within six to eight weeks they are often prescribed biologic therapies.

The NIMBLE pilot program will use Exagen's proprietary Avise PG lab test to measure whether patients are receiving an appropriate dose of MTX. Avise PG measures MTX polyglutamate levels, the active metabolites of MTX. These measurements can help establish how MTX is being absorbed, retained and metabolized by the patient. With this information, a physician can more accurately adjust the dose of MTX, making it more effective for the patient.

The Medco Research Institute will work with Medco clients to recruit patients to take part in the NIMBLE pilot program. When a member of a participating plan receives an initial prescription for MTX for the treatment for RA, Medco will provide the prescribing physician with the Avise PG test, and the member will be alerted that a blood-draw for the Avise PG test will be performed at their next office visit. Once the physician's office has collected the blood sample, it will be sent to Exagen’s CLIA-certified laboratory for testing. Exagen will provide the test results to the prescribing physician to make dose changes accordingly, and to Medco Research Institute.

It is anticipated that up to 400 Medco members who are new to MTX therapy will have the Avise PG testing performed. The downstream medical and pharmacy claims data from these patients will be compared to a similar number of Medco members who did not received Avise PG testing as part of their care in order to determine the clinical utility and cost effectiveness of this intervention.