Repeat Rituximab Courses Sustain Clinical Efficacy in Patients with RA

SAN DIEGO, CA—A sustained improvement of clinical response was seen after each retreatment course with rituximab in patients with rheumatoid arthritis (RA), with respect to Treat to Target principles and EULAR/ACR recommendations, presented Catalin Codreanu, MD, PhD, of the Department of Rheumatology at Dr. I. Stoia Center for Rheumatic Diseases in Bucharest, Romania, at the 2013 ACR/ARHP Annual Meeting.

The onset of biologic treatment options in the last decade has changed the course of therapy for RA. However, a significant number of patients failed to maintain the initial response to a tumor necrosis factor (TNF) blocker. There has been a lack of information regarding safety and efficacy of multiple courses of biologics administered over extended-periods of time.

Dr. Codreanu and colleagues conducted an open-label, multicenter, prospective observational study to assess the clinical efficacy of subsequent courses with rituximab in patients with moderately-to-severely active RA and inadequate response to at >1 TNF-inhibitor. The study was started in 2010 and 943 adult patients were treated with rituximab every 6 months.

Clinical efficacy was assessed at baseline and after each retreatment course at Months 6, 12, 18, and 24. Assessments included Disease Activity Score (28 joints; DAS-28 [4-variable assessment including CRP]), Simplified Disease Activity Index (SDAI), and Clinical Disease Activity Index (CDAI). Median clinical disease activity scores steadily decreased after each retreatment indicating improvement in clinical response as shown below:

 

DAS-28

SDAI

CDAI

Baseline

5.67 (n=943)

27.68 (n=935)

26 (n=943)

6 months

3.87 (n= 877)

10.98 (n=862)

10 (n=877)

12 months

3.38 (n=580)

7.40 (n=564)

6 (n=580)

18 months

2.96 (n=302)

4.70 (n=299)

3.80 (n=302)

24 months

2.80 (n=118)

4.44  (n=116)

3 (n=118)

Researchers also noted that remission rates progressively increased after each retreatment course: 10.95%, 18.79%, 35.1%, and 39.83% whereas the initial percentage of patients showing high disease activity (HDA) steadily decreased to 16.65%, 3.62%, 1.66% and 0.85% at Months 6, 12, 18 and 24, respectively.

In SDAI, remission rate increased from 4.28% to 11.02%, 18.79%, 31.44% and 35.34%, whereas initial proportion of patients with HDA decreased to 9.63%, 1.67%, 1.42% and 0%.

In CDAI, remission rate increased from 4.24% to 11.4%, 20.17%, 36.75% and 37.29%, with steadily decreased HDA after each retreatment, from 58.43% to 14.25%, 2.59%, 2.32% and 0%, respectively.

All changes in DAS-28, SDAI and CDAI, as well as DAS-28 vs. SDAI and DAS-28 vs. CDAI comparisons were statistically significant (P<0.0001), noted researchers. Dr. Codreanu added, “Each rituximab course led to an increased and cumulative clinical response vs. the previous one with respect to Treat to Target principles and EULAR/ACR recommendations.”

In addition, “There was sustained improvement of clinical response after each 6-monthly retreatment course with rituximab, regardless of the assessment tool used,” Dr. Codreanu concluded.
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