AB0289 EFFICACY, SAFETY AND IMMUNOGENICITY IN PATIENTS WITH RHEUMATOID ARTHRITIS COMPARING PF-06410293 (ADL-PF), AN ADALIMUMAB (ADL) BIOSIMILAR, AND REFERENCE ADL: RESULTS FROM WEEK 26–52 OF A DOUBLE-BLIND, RANDOMISED PHASE 3 STUDY INCLUDING PATIENTS WHO SWITCHED FROM ADL-PF TO REFERENCE ADL AT WEEK 26

Abstract

Background:PF-06410293 (ADL-PF) is an adalimumab biosimilar approved for the treatment of several inflammatory and autoimmune indications.1The efficacy, safety and immunogenicity of ADL-PF and reference adalimumab sourced from the European Union (ADL-EU) in patients with rheumatoid arthritis (RA) have been demonstrated to be similar in a randomised controlled trial up to 26 weeks (wks; treatment period 1 [TP1]).2Objectives:To evaluate the efficacy, safety and immunogenicity of ADL-PF and ADL-EU in patients with moderate to severe RA on longer-term treatment, and following a treatment switch from ADL-EU to ADL-PF in a subset of patients.Methods:This multinational, randomised, double-blind, parallel-group study compared ADL-PF and ADL-EU in essentially biologic-naïve patients with active RA despite methotrexate (MTX) (NCT02480153). In TP1, patients were randomised (1:1) to ADL-PF or ADL-EU (40 mg subcutaneous injection every 2 wks) for 26 wks while continuing MTX (10–25 mg/wk). The primary endpoint was achievement of American College of Rheumatology response (ACR20) at Wk 12. At Wk 26, the start of treatment period 2 (TP2), patients receiving ADL-EU were blindly re-randomised (1:1) to remain on ADL-EU or switch to ADL-PF for 26 wks while patients receiving ADL-PF continued treatment in a blinded manner. Secondary efficacy endpoints at Wks 26, 30, 36, 44 and 52 (ACR20/50/70, European League Against Rheumatism [EULAR] response, Disease Activity Score [DAS] 28-4[CRP] <2.6 and ACR/EULAR defined remission), safety events and percentage of patients with anti-drug antibodies (ADA) were assessed.Results:In TP1, 597 patients were randomised to ADL-PF (n=297) or ADL-EU (n=300). At Wk 26, 552 patients were re-randomised for TP2 (continued ADL-PF, n=283; continued ADL-EU, n=135; switched from ADL-EU to ADL-PF, n=134). Patients who demonstrated at least minimal efficacy continued in TP2. Observed ACR20 rates were comparable between treatment groups at all visits during TP2 (Figure). Other measures of deep response (ACR70, EULAR good response, DAS28-4(CRP) <2.6 and ACR/EULAR defined remission) showed maintained efficacy during TP2 in all treatment groups. Incidences of treatment-emergent adverse events were comparable between treatment groups (Table). Overall, incidences of ADA through Wk 52 were comparable between treatment groups (47.3%, 54.1% and 45.9% for patients who continued ADL-PF, continued ADL-EU or switched from ADL-EU to ADL-PF, respectively). In patients who switched from ADL-EU to ADL-PF compared with patients who continued ADL-EU, the increase in ADA incidence over TP2 was 0.8% (from 45.1% to 45.9%) versus 6.7% (from 47.4% to 54.1%), respectively.Conclusion:TP2 results demonstrated comparable efficacy, safety and immunogenicity between ADL-PF and ADL-EU was maintained up to Wk 56 and was unaffected by a blinded switch from ADL-EU to ADL-PF at Wk 26.