Background and importance Rheumatoid arthritis (RA), psoriatic arthritis (AP) and ankylosing spondylitis (AS) have a considerable impact on healthcare budgets.

Aim and objectives The aim of this study was to determine the persistence, clinical and economic impact of the use of Inflectra in RA, AP and AS naïve and Remicade switched patients.

Material and methods This was an observational, retrospective cohort study of patients treated with Inflectra for more than 6 months, between June 2015 and September 2019. We collected age, sex, indication and persistence of Inflectra naïve and switched patients. Safety was also assessed. We determined the real cost of Inflectra treatment for each patient from individualised intravenous administration, and correlated dates during the study period were collected from DISPENSA (Oncopharm). We simulated the real cost for these patients if they received Remicade. Cost savings were calculated using official Spanish prices for Inflectra and Remicade.

Results From June 2015 to September 2019, 62 patients (38 women; aged 52±20 years; weight 75±27 kg), 31 with AS, 18 with RA and 13 with AP were treated; 33 (53%) were naïve patients (15 AS, 13 RA, 5 AP) and 29 (47%) were Remicade pretreated patients (16 AS, 5 RA, 8 AP). By September 2019, 33 (54%) patients continued on Inflectra treatment (11 naïve patients and 22 Remicade pretreated patients) in clinical remission (DAS 28 <2.6 or BASDAI <2). Twenty-nine patients discontinued therapy: 24 due to relapse of their rheumatology condition and 5 patients due to adverse reactions. All patients receiving Inflectra presented persistence at 24.4±7.4 months (AS 22.7±3.7, RA 19.2±5.4, AP 31.7±6.7). Persistence in naïve patients was 19.1±4.4 months (AS 19.1±4.7, RA 13.8±3.2, AP 24.5±10.4) and in Remicade pretreated patients 29.7±5.8 months (AS 26.5±6.5, RA 24.6±7.2, AP 37.9±8.1). Total associated costs of Inflectra treatment during the observation period were 901 840€. If these patients had been treated with Remicade, the total cost of therapy would have been 1 099 803€. Implementation of this procedure saved 197 964€ over 5 years.

Conclusion and relevance Inflectra produced cost savings when used in anti-TNFα drug naïve and anti-TNFα pretreated patients. At a time when therapy cost is an unavoidable component of healthcare treatment decisions, Inflectra could be a cost effective option for patients with RA, AP and AS.

References and/or acknowledgements No conflict of interest.