Rituximab is indicated for use in combination with MTX in patients with moderately-to-severely active RA who don’t respond to one or more tumor necrosis factor (TNF) inhibitors.
In a previous study in an early active RA population initiating MTX, adding rituximab to MTX was significantly more effective compared to adding placebo (MTX-only) in terms of inhibiting joint damage and improving clinical outcomes at 52 weeks. (That study, called the IMAGE trial, was reported online this past October in the Annals of Rheumatic Diseases.)
A new analysis of the IMAGE data now demonstrates that early use of rituximab with MTX markedly improved several patient-reported outcomes, including physical function, fatigue and pain, compared to MTX alone.
Dr. William Rigby of Dartmouth Medical School in Lebanon, New Hampshire, and colleagues report the newest findings in the December 8th online issue of Arthritis Care & Research.
Altogether, 748 patients were randomized to MTX plus placebo or MTX plus rituximab. Rituximab was given intravenously, either 500 or 1000 mg, on days 1 and 15. MTX was started at 7.5 mg/week and titrated to 20 mg/week by week 8.
According to the investigators, patients in both rituximab dose groups achieved more than a 50% improvement over baseline in mean Health Assessment Questionnaire disability index (HAQ-DI), compared with a 34% improvement in this measure in the MTX-only group.
This level of improvement in HAQ-DI is particularly important in this relatively young, working age patient population (mean age, 48 years), the researchers note, given that this index has been shown to independently predict work disability.
Health-related quality of life also improved more in the rituximab arms. At baseline, scores on the Short Form-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) and 8 domain scores were 10 to 20 points (1 to 2 standard deviations) below the average score of 50 for the US population. Over the 52-week study, patients taking rituximab plus MTX gained an average of 8 to 10 points on most of the SF-36 sub-scales, bringing their scores closer to the US average.
Fatigue scores also improved significantly in the rituximab groups, which may reflect the lessening of chronic pain, the researchers say.
The study was supported by Genentech, Inc. (the maker of rituximab), Hoffmann-La Roche and Biogen Idec.
Arthr Care Res 2010.