AB0447 Audit of the clinical efficacy and safety of etanercept biosimilar to its reference product in patients with inflammatory arthritis: experience from a district general hospital in the united kingdom

Background Etanercept has been widely used in rheumatology practice since NICE approval in 2000. Biologics have been pivotal treatments for inflammatory arthritis but are associated with a considerable economic burden. The expiry of patent protection has led to the introduction of biosimilar drugs at competitive prices. SB4 was the first biosimilar of etanercept approved by the European Medicine Agency. SB4 was launched in February 2016 in the UK for use in all adult indications for which reference etanercept is approved. The rheumatology team at the Dudley Group of Hospitals (DGH) negotiated with commissioners to share the cost savings of switching the cohort of patients who were on reference etanercept to SB4 Objectives This audit aimed to compare the clinical efficacy and safety profile of etanercept biosimilar SB4i (post switch) with its reference etanercept (pre switch). Methods The first 50 patients switched were sampled and followed up for 6 months. Data was collected from hospital databases and patient records (demographic; disease activity scores 6 months pre and post switch; adverse events(AE)). Inclusion criteria: all patients established on reference etanercept for more than 12 months. Exclusion criteria: patients attempting to conceive, pregnanct or breast feeding women, patients on 25mg of reference etanercept or with JIA. Results Of the 194 patients on reference etanercept in the Dudley area, 160 (83%) were successfully switched at the time of audit. Of the first 50 patients who switched, 32 (64%) patients had rheumatoid arthritis (RA), 15 (30%) ankylosing spondylitis (AS), and 3 (6%) psoriatic arthritis (PsA). The mean age was 60 years (range 29-83 years) with equal gender distribution. Mean years on reference etanercept was 6 years (range 1-13 years). In the RA cohort: 23(72%) patients were female with mean change of DAS28: +0.1(SD:0.87). In the AS cohort,14(93%) patients were male with mean change of BASDAI: -0.6 (SD:1.34). PsA: 2 pateints’ symptoms were unchanged, 1 patient’s tender and swollen joint count decreased. At 6 months post switch, 84% patients continued etanercept biosimilar SB4. Reasons for discontinuation included: AE (n=4), inefficacy (n=3) and new contraindication (cancer n=1). Conclusions Following switching to etanercept biosimilar SB4, no clinically significant change in DAS28 or BASDAI were observed during the audit period. Switching from reference etanercept to SB4 has resulted in a potential yearly saving of £660,000, from which the rheumatology department has secured funding to employ an additional clinical nurse specialist and secretary. Our audit found SB4 to be as safe and effective as its reference etanercept and has demonstrated a positive experience with biosimilar switching. This is relevant given the expiry of ther biologic drugs’ patent protections and further biosimilar drugs becoming available. Disclosure of Interest None declared