Study: Test May Lead to Individually Tailored Methotrexate for Rheumatoid Arthritis

A new test that monitors the effectiveness of methotrexate may allow physicians to individually tailor doses for rheumatoid arthritis patients, according to a study presented October 27 at the American College of Rheumatology's annual scientific meeting.

Nearly 40 percent of rheumatoid arthritis patients take methotrexate, making it one of the most frequently prescribed disease modifying anti-rheumatic drugs.

According to the researchers, the current treatment approach of "start low and go slow" often results in sub-optimal methotrexate dosing, and highlights the need to find a better way to determine whether patients are responding to methotrexate.

Known as Trexscore®, the new test measures levels of long-chain methotrexate polyglutamate in the blood of patients taking methotrexate. The test, which is being developed by Prometheus Laboratories, may be on the market early next year.

The study involved 114 rheumatoid arthritis patients who contributed blood samples for the tests. Those with a long-chain methotrexate polyglutamate level above a certain threshold were found to be 14 times more likely to have a good clinical response than patients with lower levels.

"Rheumatologists trust methotrexate as the standard of care in rheumatoid arthritis," said Dr. Joel M. Kremer, research director at the Center for Rheumatology in Albany, N.Y. "Rheumatologists are looking for ways to better understand methotrexate therapy, and a therapy monitoring test could offer some help in understanding response."

Other sources: Prometheus Laboratories