P1058 Safety and effectiveness of subcutaneous infliximab formulation in difficult-to-treat Crohn’s Disease patients with previous exposure to intravenous infliximab: A case-series

Abstract

Background: Despite the increased therapeutic armamentarium for Crohn's Disease (CD), a relevant proportion of patients fail to respond to multiple therapies and ultimately require surgery. Intravenous (IV) infliximab (IFX) reinduction after a drug holiday is associated with reduced drug efficacy and both acute and delayed infusion reactions, due to immunological mechanisms and development of antidrug antibodies, and is currently contraindicated. Recently, a subcutaneous (SC) formulation of IFX has been developed, demonstrating equal efficacy and safety with a better immunogenicity profile (i.e. biobetter). This study evaluated the safety and effectiveness of retreatment with SC IFX in CD patients previously exposed to IV IFX. Method(s): Data were retrospectively collected through the Electronic Medical Record. Patients included were IV IFX-experienced and subsequently treated with SC formulation after a period of drug holiday >= 1 year. Collected data included demographics, disease characteristics and activity, current and previous treatment, adverse events, and reasons for previous anti-TNFalpha discontinuation. Result(s): 12 patients with CD were included. Mean age at diagnosis and disease duration were 16.2 (?}6.7 SD) and 15.6 years (?}7.4 SD) respectively. All patients had failed at least three biologics, and 7 patients underwent previous surgery. The main reason for IV IFX discontinuation was secondary failure (4 patients, 33%). Median time from IV suspension to SC treatment start was 106.5 months (IQR=98.5) with median treatment duration of 24 (IQR=37.5) and 7.5 (IQR=4.5) months for IV and SC IFX respectively. SC IFX was introduced as an add-on dual biologic therapy in 5 patients (3 treated with Ustekinumab, 2 with Vedolizumab). Overall, one adverse event with SC IFX was reported: a grade 2 serum sickness reaction, which led to treatment discontinuation. No immediate allergic reactions were reported. 10 patients had at least 6 months of follow-up. Median HBI reduction at 6 months from SC IFX begin was significant (p<0.05), varying from 7.5 (IQR=3.5) to 3.5 (IQR=4). C-Reactive Protein levels normalized in 3 (38%) patients, reduced in 2 (25%), and remained stable in 3 (38%). Faecal calprotectin normalized in 2 (29%) patients, reduced in 1 (14%), remained stable in 2 (29%), and increased in 2 (29%). At 6 months steroid free remission rate (HBI