A56 CLINICAL AND BIOCHEMICAL EFFICACY ARE NOT AFFECTED BY SWITCH FROM INFLIXIMAB ORIGINATOR TO RENFLEXIS IN PEDIATRIC INFLAMMATORY BOWEL DISEASE PATIENTS.

Abstract

Abstract Background Increased infliximab (IFX) utilization has generated higher drug expenditures and cost burden to the healthcare system. The expiration of the IFX originator Remicade patent led to the addition of biosimilar agents to the drug market that may reduce drug expenditures. In British Columbia, Pharmacare’s 2019 biosimilar initiative mandated all pediatric inflammatory bowel disease (IBD) patients on Remicade to switch to the biosimilar Renflexis. To date, there is limited pediatric IBD data demonstrating that switching from IFX originator to IFX biosimilar CT-P13 is safe and effective, and no data on switching to Renflexis. Aims To determine the proportion of patients remaining on Renflexis 6 months after switch from originator IFX. The secondary aims are to determine the proportion of patients remaining in clinical and biochemical remission after switch. Methods In this prospective, longitudinal observation single-center study, all children with Crohn’s disease and ulcerative colitis receiving maintenance IFX originator therapy were switched to Renflexis by May 15th 2020. Baseline demographics, concomitant therapy, clinical disease indices (wPCDAI, PUCAI), growth data, blood work, fecal calprotectin and IFX drug levels were collected at baseline and prospectively from 6 months after the switch. All data are presented as median and interquartile range. Results A total of 139 children (110 CD, 25 UC and 4 IBDU; Median age 16.2 (3.7) years) with a median IFX originator duration of 42.7 (35.1) months before switching to Renflexis were included. 137/139 (99%) of patients remained on Renflexis at study end. The proportion of children in clinical remission from baseline to 6 months post switch was unchanged (133/139 (95.7%) vs. 130/132 (98.5%), p=0.17). There was no significant change pre and post switch in median CRP (<5 (0) mg/L vs <5 (0) mg/L, p=0.26) or fecal calprotectin (72.5 (144.2) ug/g vs. 65.5 (140.0) ug/g, p=0.87). There was no significant change pre and post switch in the proportion of patients with normal CRP (<5 mg/L) (89/103 (86.4%) vs 89/98 (90.8%), p=0.33) or normal fecal calprotectin (<250 ug/g)(91/112 (81.2%) vs 51/63 (80.9%), p=0.60). There was no significant change pre and post switch in IFX trough level (15.5 (12.3) ug/mL vs 17.5 (12.9) ug/mL, p=0.42). 2 patients had antibodies to IFX after switching. Safety profile is improved with adverse events in 38/139 (27.3%) children on IFX originator vs. 11/139 (7.91%) children on Renflexis for 6 months. Conclusions Pediatric IBD patients can be successfully switched from IFX originator to biosimilar Renflexis during maintenance without affecting efficacy, immunogenicity or safety in the short term. Funding Agencies None