Evaluating predictors for poor methotrexate response in patients with rheumatoid arthritis: can co-treatment with adalimumab improve disease symptoms?

This study investigated if there are disease features that can predict if a patient with rheumatoid arthritis will respond well to methotrexate treatment. They found that higher disease activity at early stages of treatment predicted a poor treatment response in these patients.

Treatment of rheumatoid arthritis (RA) requires drugs to reduce inflammation. The first line of treatment for RA is methotrexate (MTX). MTX reduces inflammation by targeting a number of cells and proteins that are overactive in patients with RA.

Some patients do not respond well to MTX. These patients may benefit from other drugs that are more specific, such as biological therapy. Biological therapy targets specific molecules or proteins. Adalimumab (Humira) is a biological drug that blocks an inflammatory chemical called tumor necrosis factor (TNF). It is unclear if there are any factors or clinical signs that might predict if a patient will not respond to MTX and if these patients may benefit from the addition of adalimumab to their treatment.

This study analyzed data from 2 clinical trials. In these trials, patients were taking adalimumab plus MTX, adalimumab alone or MTX alone. Patients were treated for up to 2 years and had regular visits with their physician to measure treatment response. Disease activity and physical function were measured using a number of scoring methods.

A first analysis evaluated possible factors that could predict a poor response to MTX treatment. 687 patients treated with MTX alone were included. Patients that did not respond to MTX after 6 months of treatment were 76.9% more likely to have higher disease activity at the beginning of the study. Patients with a higher disease activity during the first 12 weeks of MTX treatment were 3.4 times more likely to have a poor response to long-term MTX treatment. 

A second analysis included 525 patients with a poor response after 6 months of MTX treatment. Of these, 33.7% continued MTX alone therapy and 66.3% had adalimumab added to their treatment. After one more year of treatment, significantly more patients who also received adalimumab (64%) achieved a lower disease activity compared to patients treated with MTX alone (41%).

The authors concluded that higher disease activity at the beginning of treatment could predict a poor methotrexate response in patients with rheumatoid arthritis. They also found that the addition of adalimumab to MTX can improve disease outcomes for these patients.

This study was funded by the pharmaceutical company AbbVie, the manufacturer of Humira.  

If you have any concerns regarding treatment for rheumatoid arthritis please discuss this with your physician.