High Retention Rates in Tocilizumab-Treated Patients With RA and Inadequate Response to csDMARDs, TNF

Tocilizumab was deemed safe and effective in patients with rheumatoid arthritis (RA) who had inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and/or tumor necrosis factor inhibitors (TNFs). As 86% of patients continued to receive tocilizumab treatment at month 12, the drug retention rate was considered satisfactory, according to a study published Turkish Journal of Medical Sciences.¹

Güzide Nevsun İnanç, PhD

Credit: Marmara University

Remission and low disease activity are recommended as treatment goals according to both American College of Rheumatology (ACR) and European Alliance of Associations for Rheumatology (EULAR) guidelines. Initial treatment is traditionally a csDMARD, although TNFs and biologic DMARDs (bDMARDs) have also been introduced as RA management options in the last decades.²

“However, approximately 30% – 40% of patients develop an inadequate response to csDMARDs and TNFs,” wrote Güzide Nevsun İnanç, PhD, Division of Rheumatology, Department of Internal Medicine, Marmara University, İstanbul, Turkey, and colleagues. “The increasing knowledge about the pathogenesis of RA and potential targets for treatment resulted in the introduction of new bDMARD options (non-TNF biologics) with different mechanisms of action and targeted synthetic DMARDs (tsDMARDs).”

Investigators used retrospective data collected from patients’ files between January 2020 and September 2020 to evaluate the disease activity and retention rate of tocilizumab, a humanized monoclonal antibody against the interleukin-6 (IL-6) receptor, in this patient population. Both retention rates and the Disease Activity Score in 28 joints with C-reactive protein (DAS28-CRP) were assessed throughout the analysis.

The relationship of drug efficacy with factors including smoking, obesity, and previous TNF use were analyzed. Other data obtained included demographics, disease duration, laboratory information, adverse events, data of treatment initiation and discontinuation, and route of administration.

In total, 124 patients with a median disease duration of 3.7 years were included in the national, multicenter, noninterventional study. The mean age of patients was 52.9 years and most (75%) were female. At baseline, 25% (n = 31) of patients had previous TNF exposure.

At months 6 and 12, tocilizumab retention rates were 94.1% and 86.6%, respectively. DAS28-CRP level decreased significantly from baseline through month 6 in all patients. An increase in remission and/or low disease activity was also observed. This was coupled with a decrease in patients with high disease activity at months 3 and 6 (P <.001).

At all time points, disease activity was comparable between subgroups based on previous use of TNF, smoking status, and body mass index (BMI). Additionally, the regression analysis revealed the absence of concomitant corticosteroid treatment was linked to remission and/or low disease activity at both month 6 (odds ratio [OR] = .31, 95% CI [.14 – .72], P = .006) and month 12 (OR = .35, 95% CI [.13 – .94], P = .037). Throughout the study period, 25 mild adverse events were observed.

Investigators noted limitations of the analysis included the retrospective design and the small number of patients refractory to TNFs. Additionally, the number of patients who followed up after month 12 was low due to follow-up challenges in routine clinical practice. The lack of a control group also hindered the analysis of results.

“Tocilizumab drug retention rates of 94.1% and 86.6% at months 6 and 12 respectively were concordant with previously conducted tocilizumab clinical studies and tocilizumab seemed to be effectively showing favorable DAS28-CRP response rates in routine clinical practice in patients with moderate to severe RA responding inadequately to csDMARDs and/or TNFs,” investigators concluded.

References

1. ^{İnanç GN, Terzioğlu ME, Karabulut Y, et al. A national, multicenter, retrospective study evaluating retention rate and efficacy of tocilizumab treatment in patients with active rheumatoid arthritis who had an inadequate response to csDMARDs and/or TNF inhibitors. Turk J Med Sci. 2023;53(3):731-743. doi:10.55730/1300-0144.5636}
2. ^{Smolen JS, Landewé RBM, Bijlsma JWJ, Burmester GR, Dougados M et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Annals of the Rheumatic Diseases 2020; 79 (6): 685- 699. https://doi.org/10.1136/annrheumdis-2019-216655}