Real-Life Rituximab: Prospective Study Echoes RA Clinical Trials

March 31, 2014

A study of rituximab use for rheumatoid arthritis in clinical practices in Germany finds efficacy similar to clinical trial results, plus no age-related differences and a biomarker for good outcomes.

Wendler J, Bumester GR, Sörensen H, et al., Rituximab in patients with rheumatoid arthritis in routine practice (GERINIS): 6-year results from a prospective, multicentre, non-interventional study in 2,484 patients.Arthritis Research & Therapy 2014, 16:R80 doi:10.1186/ar4521 [Published online: 26 March 2014] Open access.

A six-year trial designed to track the efficacy and safety of rituximab  (Rituxan, RTX) treatment in routine clinical practice found sustained improvement in rheumatoid arthritis (RA) for more than 10 months.

The authors say the results are similar to those from clinical tials of these drugs in this patient population.

The non-intervention study involving 2,484 patients in Germany involved mostly rheumatoid factor (RF) positive women in their 50s taking disease modifying anti-rheumatic drug (DMARD) therapy, including biologicals like etanercept.

During the first round of RTX, Disease Activity in 28 Joints (DAS28) scores were reduced by 1.4 points at both four and eight months into treatment, and physician-reported tender and swollen joint counts had dropped by almost half. Decreases continued during subsequent courses: By the third course of RTX, DAS28 scores dropped to 3.6 from a baseline of 5.7 at both the four and eight-month time points, and Health Assessment Questionnaire-Disability Index (HAQ-DI) scores also showed clinically meaningful improvements.

Efficacy was similar in 564 patients on RTX monotherapy, contrary to some other studies, and did not vary significantly by age. This appears to be the first report of age-independent efficacy for RTX.

However, RF-positive patients responded better to RTX, with improvement in DAS28 from baseline to four months associated with higher baseline RF readings up to 50 IU/ml. RF proved to be a distinct and accurate biomarker of RTX responsiveness over time.

The study also found that effects lasted on average about 10 months, while guidelines recommend retreatment at six months. With experience, physicians in the trial became comfortable with earlier retreatment even of patients who had lower disease activity, the authors said.