What is the success rate of Rituxan (rituximab) in rheumatoid arthritis?

Key Points

• Rituxan (rituximab) is a monoclonal antibody used for rheumatoid arthritis (RA) and other conditions like non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL).
• It is prescribed with methotrexate for moderate to severe RA in patients who haven’t responded to TNF inhibitors.
• Clinical trials show significant symptom improvement, better quality of life, and slower joint damage progression with Rituxan.

What is Rituxan?

Rituxan (rituximab) is a monoclonal antibody, which works by targeting the CD20 protein antigen displayed on the surface of B-cells. It is used in the treatment of rheumatoid arthritis and also for a number of other conditions including non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukemia (CLL), granulomatosis with polyangiitis (GAP) and moderate to severe pemphigus.

How Effective Is Rituxan for RA?

Studies confirm Rituxan reduces symptoms, fatigue, and disability, while also improving health-related quality of life. In clinical trials, the ACR (American College of Rheumatology) response criteria measures how much a patient’s symptoms have improved between two set points in time. ACR20, ACR50 and ACR70 are commonly reported. Patients achieving ACR20, ACR50 and ACR70 show a ≥20%, ≥50% and ≥70% improvement in symptoms between the two set time points, respectively. The ACR criteria looks at the number of swollen and tender joints a patient has, c-reactive protein levels, erythrocyte sedimentation rates and other measures of pain, disability and disease activity.

Rituxan Plus Methotrexate vs. Methotrexate Alone

The REFLEX clinical trial evaluated Rituxan in RA patients with poor response to TNF inhibitors. After 24 weeks:

• 51% of patients on Rituxan + methotrexate achieved an ACR20 response (≥20% symptom improvement) vs. 18% on placebo.
• 27% reached ACR50 (≥50% improvement) vs. 5% on placebo.
• 12% achieved ACR70 (≥70% improvement) vs. 1% on placebo (p<0.0001).
• 65% of Rituxan-treated patients met moderate-to-good EULAR response criteria vs. 22% on placebo plus methotrexate (p<0.0001).

A separate phase III trial called SUNRISE, in which patients received a second course (re-treatment) of Rituxan, also showed Rituxan plus methotrexate to be better than placebo plus methotrexate.

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Quality of Life and Fatigue Improvement

Rituxan also showed improvements in fatigue, physical function, and mental health:

• Rituxan-treated patients had a significant reduction in levels of fatigue as measured by the FACIT-F (Functional Assessment of Chronic Illness Therapy - Fatigue) scale. Their scores decreased by 9.1 points on average, representing a 29.6% improvement in their levels of fatigue, compared with only a 0.5 point decrease in patients who didn’t receive Rituxan.
• Six percent of Rituxan-treated patients had an HAQ DI score of 0 at 24 weeks, compared with 0.5% of patients who didn’t receive Rituxan. HAQ DI - the Health Assessment Questionnaire Disability Index - is a questionnaire used to determine a patient’s functional ability, including their ability to dress, eat, walk, reach, take care of themselves and more.
• Rituxan-treated patients had significant improvements in their mental and physical health, as measured by the SF-36, a 36-item short form survey. Mental and physical health domain scores increased by 4.7 and 5.8, respectively, in patients treated with Rituxan plus methotrexate, compared with increases of only 1.3 and 0.9, respectively, in patients who didn’t receive Rituxan (p=0.0002).

Does Rituxan Help Prevent Joint Damage?

Yes. In a long-term REFLEX trial extension, Rituxan helped slow structural joint damage:

• 60% of patients had no radiographic progression at 1 year (vs. 46% on placebo).
  68% had no progression at 2 years, an improvement from year 1.
• Of those without progression in year 1, 87% remained stable in year 2.
• Overall, 57% of Rituxan-treated patients had no joint damage progression at 2 years.

Rituxan significantly reduces RA symptoms, improves quality of life, and slows joint damage. It is typically used after TNF inhibitors fail. Patients should discuss risks and benefits with their doctor before starting treatment.