Real-World Dose Modification Patterns of Subcutaneous Tocilizumab Among Patients with Rheumatoid Arthritis.

Background: The treatment of rheumatoid arthritis is based on the use of disease-modifying antirheumatic drugs (DMARDs). Tocilizumab can be used as monotherapy or in combination with conventional synthetic DMARDs for the treatment of moderate-to-severe active rheumatoid arthritis. Subcutaneous (SC) and intravenous forms of the drug are available, but the SC form is more widely used.

Objective: To understand the real-world dose modification patterns of SC tocilizumab in the treatment of patients with rheumatoid arthritis in the United States.

Methods: Data were obtained from the Truven (now IBM) MarketScan and Optum Clinformatics databases. Patients were included if they had ≥1 pharmacy claims for SC tocilizumab and met other inclusion criteria. The mean, standard deviation, and median values were reported for the continuous variables, and frequency was reported for the categorical variables. Kaplan-Meier analysis was used to analyze the time to first dose modification. Logistic regression modeling was used to identify predictors of the likelihood of dose modification.

Results: The study included 1266 patients in the Truven database and 512 patients in the Optum database who had commercial or Medicare Advantage or supplemental insurance. Of the patients who started treatment with biweekly SC tocilizumab (48% each in the Truven and Optum databases), 37% in Truven and 40% in Optum had dose escalation to a weekly dose. Of those who started weekly SC tocilizumab (43% in the Truven and 49% in the Optum databases), 3% (Truven) and 4% (Optum) had dose reduction. The remaining patients started alternative SC tocilizumab doses. Overall, 60% and 68% of patients in the Truven and Optum cohorts, respectively, initiated or escalated to the higher weekly dose of tocilizumab; the mean time to dose escalation was 126 days and 112 days, respectively. In the Truven cohort, corticosteroid use, age, and anemia were the main predictors for dose escalation. In the Optum cohort, female patients had increased odds of dose escalation compared with male patients.

Conclusion: The dosing trends observed in this study show that physicians have taken advantage of the option to increase SC tocilizumab dosing, but only a few providers chose to reduce the dose. This trend in dose modification may increase the costs related to SC tocilizumab therapy.