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

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. Methods 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-TNFα discontinuation. Results 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≤4) was 66%. Conclusion This is the first report showing that SC IFX reinduction in CD patients previously exposed to IV IFX is safe, even after a long drug holiday. It might be regarded as a rescue option in difficult-to-treat patients, either alone or combined with other immunosuppressants.