Background/Purpose:

In the last decade, biologic therapy changed dramatically treatment options for rheumatoid arthritis (RA). However, a significant number of patients failed to maintain the initial response to a TNF blocker. More information is needed regarding efficacy and safety of multiple courses of biologics administered over extended periods of time.

We tried to assess clinical efficacy of subsequent courses with Rituximab (RTX) in patients with moderate-severe active RA despite treatment with a TNF inhibitor in routine clinical practice in Romania.

Methods: In this open-label, multicentre, prospective observational study started in 2010, patients were treated with RTX at each 6 months. Clinical efficacy was assessed at baseline and after each retreatment course at 6, 12, 18 and 24 months. Clinical assessments included DAS-28, SDAI and CDAI. Δ DAS-28, Δ SDAI and Δ CDAI were calculated based on two consecutive evaluations. Statistical analyses: STATA SE 11.0 software, unpaired t-tests and Pearson correlation coefficients R2 in regression analysis (for Δ DAS-28, Δ SDAI and Δ CDAI) and Cuzick non-parametric trend tests across ordered groups (for disease activity state).

Results:

943 adult (>18 years) patients with active RA and inadequate response to at least one TNF inhibitor received initial RTX treatment. Median clinical disease activity scores steadily decreased after each retreatment indicating improvement in clinical response:

Evaluation	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)

* Patient’s number (n) decreases in time because of the enrolment timeframe and represents the number of patients who reached each evaluation (data cut-off 1^st of December 2012)  

** SDAI patient’s number is lower as CRP was not dosed to all patients analysed

Remission rate progressively increased after each retreatment course: 10.95%, 18.79%, 35.1% and 39.83%, whereas initial percentage of patients showing high disease activity (HDA) (63.94%) steadily decreased to 16.65%, 3.62%, 1.66% and 0.85% at 6, 12, 18 and 24 months, respectively. Similar trends were observed in SDAI and CDAI scores. 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 (53.48%) decreased to 9.63%, 1.67%, 1.42% and 0%. Similarly, 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 Δ DAS-28, Δ SDAI and Δ CDAI changes, as well as DAS-28 vs. SDAI and DAS- 28 vs. CDAI comparisons were statistically significant (p<0.0001).

Conclusion: Our study showed a sustained improvement of clinical response after each retreatment course with RTX (at 6 months interval), regardless of assessment tool used (DAS28, SDAI or  CDAI). Each RTX course led to an increased and cumulative clinical response versus the previous one with respect to Treat to Target principles and EULAR/ACR recommendations.

---

« Back to 2013 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/sustained-clinical-efficacy-after-multiple-courses-of-rituximab-in-rheumatoid-arthritis-patients-with-inadequate-response-to-tumour-necrosis-factor-inhibitors-2-year-data-from-the-repeat-repeated-co/