Background/Purpose: For RA patients not meeting their treat-to-target goals despite treatment with their first biologic (b)DMARD, ACR guidelines recommend switching to a different bDMARD or Janus kinase inhibitor (JAKi).¹ Shorter treatment duration was reported for TNF-α inhibitors (TNFi) than non-TNFi bDMARDs;^2,3 little data exist for JAKi. Understanding treatment and dosing patterns and persistency among treatment classes can optimize next-treatment selection in RA patients switching from initial bDMARD to another treatment.

Methods: In a US health-plan claims database, we identified adult RA patients who initiated a bDMARD (1/1/2012–3/31/2017) and switched (index date) to another bDMARD or JAKi (as monotherapy or in combination with a conventional synthetic [cs]DMARD). Patients had ≥2 RA diagnoses ≥30 days apart and 12-month pre- and ≥12-month post-ID continuous enrollment. Treatment patterns before and after the switch were assessed. Index-treatment dose modifications (≥10% daily-dose increase or decrease) were evaluated. Persistency was evaluated as the risk of treatment discontinuation (via Cox proportional hazards models) – among all, within index monotherapy, within index combination therapy.

Results: A total of 4656 patients switched from a first (pre-index) bDMARD to another (index) treatment (78% female, median age 54 years, RA duration 1.5 years). As pre-index bDMARD, 90.0% of patients used TNFi. Upon changing treatment, 65.4% started another TNFi, 23.4% non-TNFi, and 11.2% JAKi. Most (68%) patients on pre-index TNFi cycled to another TNFi, 22% switched to a non-TNFi, and 10% switched to JAKi. Patients with non-TNFi as first bDMARD switched to TNFi (43%), another non-TNFi (32%), or JAKi (25%; Table 1).

Within 3, 6, and 12 months, the percentages of patients with dose increase ranged: 0.6–6.6% JAKi, 2.3–11.6% TNFi, 9.4–20.2% non-TNFi; dose decrease: 0–0.6% JAKi, 3.0–5.4% TNFi, 4.3–10.5% non-TNFi. Time to dose change was longer in JAKi than in bDMARD treatments (Table 2).

Patients were significantly more likely to discontinue monotherapy than combination therapy (hazard ratio [HR]=2.0). Within monotherapy, patients were more likely to discontinue TNFi than JAKi (HR=1.25). Within combination therapy, TNFi + csDMARD where more likely to be discontinued than JAKi + csDMARD (HR=1.31). In all models, discontinuation risk increased in patients with unknown vs commercial types of insurance (overall HR=1.62, monotherapy HR=1.72, combination therapy HR=1.54); treatment discontinuation risk increased with shortened duration of RA (HR=0.92 for all) and increased number of concomitant medications (HR=1.02 for all; Table 3).

Conclusion: For RA patients switching from first bDMARD to another treatment, TNFi was the most common drug class before and after switch. After switch, JAKi demonstrated higher treatment persistency than TNFi. Dose increases were most common in non-TNFi, followed by TNFi, and least common in JAKi.

References

1. Singh JA, et al. Arthritis Rheumatol. 2016; 1-26.
2. Chastek B, et al. Adv Ther. 2017; 2422-35.
3. Wilke T, et al. BMC Musculoskelet Disord. 2017; 332-42.

Tx pattern_Table 1

Tx pattern_Table 2

Tx pattern_Table 3

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/treatment-patterns-dose-change-and-treatment-discontinuation-in-ra-patients-switching-from-first-biologic-dmard-to-another-treatment-in-the-us/