Patient-Reported Outcome Measures in Patients with Rheumatoid Arthritis, Psoriasis, or Psoriatic Arthritis Treated with GP2015, an Etanercept Biosimilar: Results from Two Phase III Studies (EGALITY and EQUIRA).

Background and objective: GP2015 is an etanercept biosimilar. Equivalent efficacy and comparable safety of GP2015 to reference etanercept (ref-ETN) was demonstrated in two phase III studies, one in patients with moderate-to-severe chronic plaque-type psoriasis (PsO; EGALITY study) and the other in patients with rheumatoid arthritis (RA; EQUIRA study). EGALITY also included patients with reported psoriatic arthritis (PsA). Here, patient-reported outcome (PRO) data from both studies are presented.

Methods: EGALITY included 531 patients with PsO and EQUIRA included 376 patients with RA. In EGALITY, patients who had achieved ≥ 50% improvement in Psoriasis Area and Severity Index (PASI) at week 12 either continued the initial treatment or underwent three treatment switches between GP2015 and ref-ETN starting at week 12. In EQUIRA, patients with at least moderate European League Against Rheumatism response at week 24 received GP2015 up to week 48. Assessed PROs included Dermatology Life Quality Index (DLQI) and EuroQol five-dimension health status questionnaire (EQ-5D-5L) in EGALITY, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score in EQUIRA, and Health Assessment Questionnaire-Disability Index (HAQ-DI) in both studies.

Results: In EGALITY, mean DLQI decreased from baseline in the GP2015 and ref-ETN groups, and the mean (standard deviation [SD]) percent reductions from baseline in DLQI were comparable between groups at week 12 (GP2015, - 67.7 [40.7]; ref-ETN, - 67.3 [30.6]), and were sustained after the switch at week 52 ('continued GP2015,' - 77.3 [36.5]; 'continued ref-ETN,' - 72.8 [33.7]; 'switched GP2015,' - 73.9 [37.0]; 'switched ref-ETN,' - 78.1 [30.9]). The proportion of patients with EQ-5D-5L scores of 1 ('no problems') improved from baseline to week 52 for all five dimensions and was comparable between treatment groups. In EGALITY, in patients with reported PsA at baseline, mean (SD) HAQ-DI scores decreased from baseline, and scores were comparable between treatment groups at week 12 (GP2015, 0.6 [0.7]; ref-ETN, 0.6 [0.6]) and after switching at week 52 ('continued GP2015,' - 0.4 [0.6]; 'continued ref-ETN,' - 0.4 [0.6]; 'switched GP2015,' - 0.4 [0.6]; 'switched ref-ETN,' - 0.1 [0.4]). In EQUIRA, the proportion of patients achieving HAQ-DI in normal range (≤ 0.5) was comparable between treatment groups up to week 48 ('continued GP2015,' 36.7%; 'switched to GP2015,' 39.9%). The mean FACIT-Fatigue scores increased from baseline and the mean (SD) percent change from baseline in FACIT-Fatigue score at week 24 was 9.6 (9.5) in the 'continued GP2015' and 11.4 (9.7) in the 'switched to GP2015' groups; the scores were sustained after switching until week 48.

Conclusion: Treatment with GP2015 and ref-ETN resulted in similar improvements in PROs and quality-of-life scores across the three diseases, namely RA, PsA, and PsO. These improvements were sustained after switching, with consistent benefit on PROs during the treatment period.

Trial registration: ClinicalTrials.gov identifiers: NCT01891864, NCT02638259.