Background In the light of scientific data, the medical and pharmaceutical community (rheumatology, gastroenterology, internal medicine) decided to use Inflectra for any patient requiring initiation, and proposed substituting Remicade with Inflectra in patients requiring maintenance therapy. Infliximab represents the first drug cost in our hospital.

Purpose The mains objectives were to evaluate the therapeutic maintenance rate after the third infusion of Inflectra and the cost savings. A secondary objective was to analyse the reasons of stopping Inflectra or returning to Remicade.

Material and methods Since October 2015, Inflectra was prescribed to adult patients requiring initiation, and substitution of Remicade with Inflectra was proposed to adult patients needing maintenance therapy (at least three Remicade infusions). The number of refusals and return to Remicade after substitution was analysed. Costs savings during the 10 month study period were estimated. Disease activity between the beginning and end of the study, changes in infliximab biosimilar residual levels and tolerance were also studied.

Results Inflectra initiations involved 66 patients (41 in rheumatology, 23 in gastroenterology, 2 in internal medicine). Substitutions were carried out in 267 patients (178 in rheumatology, 63 in gastroenterology, 26 in internal medicine). 1 patient remained on Remicade for current in vitro fertilisation. The therapeutic maintenance rate at the third infusion was 85.4% (228 patients). Among the 39 patients who discontinued Inflectra after substitution, 31 returned to Remicade, 4 changed to a subcutaneous biotherapy, 2 stopped the anti-TNF therapy for medical reason and 2 were lost to follow-up. The main reason for returning to Remicade was loss of efficacy of Inflectra (30 patients). Tolerance was deemed satisfactory with the exception of an allergic reaction requiring discontinuation of treatment. Cost savings were estimated at €733 236 (29.7% savings): €133 596 for patients with Inflectra initiation and €599 540 regarding substitution. Analysis of other secondary clinical and biological criteria is ongoing.

Conclusion The therapeutic maintenance rate obtained (greater than 80%) is encouraging. The main reason for stopping Inflectra was loss of efficacy. Substitutions allowed 4.5 more savings than initiations alone to be made. Finally, analyses currently ongoing will provide additional information on the efficacy and safety of Inflectra and prediction of maintenance.

No conflict of interest