Efficacy and Safety of Switching From Intravenous to Subcutaneous Infliximab for Psoriasis: A Case Series

Infliximab is a chimeric human-murine anti-tumour necrosis α monoclonal antibody used to treat chronic plaque psoriasis (CPP), psoriatic arthritis, ankylosing spondylitis, rheumatoid arthritis (RA) and inflammatory bowel disease (IBD) [1]. Traditionally, infliximab is administered via intravenous (IV) infusion for psoriasis at a dose of 5 mg/kg at 0, 2 and 6 weeks, followed by maintenance infusions every 8 weeks [1]. A subcutaneous (SC) preparation of infliximab is now available in the form of the biosimilar monoclonal antibody Remsima [2]. Remsima has demonstrated safety and non-inferiority compared to IV infliximab in two industry-funded randomised control trials in RA and IBD [3]. For treatment of psoriasis, an induction phase with 5 mg/kg IV infliximab at 0 and 2 weeks is required before transitioning to fortnightly SC injections of 120 mg (prefilled syringe or pen device), irrespective of patient weight [2]. Remsima is available under the Pharmaceutical Benefits Scheme for patients over 18 years of age with severe CPP. It must be prescribed by a dermatologist as systemic monotherapy (except methotrexate), and for maintenance/continuing treatment, the response must be adequate and reviewed regularly [4]. The potential benefits of SC administration include increased convenience, fewer hospital visits and pharmacoeconomic advantages for health systems [3]. In patients with IBD who have switched from IV to SC infliximab, outcomes have shown high rates of ongoing clinical remission and minimal adverse effects [5]. However, there are no published data on outcomes for dermatology patients who have made the switch, and some patients who are well established on IV infliximab are hesitant to change their route of administration. We reviewed the charts of all patients across three institutions who were switched from IV to SC infliximab (Table 1). Eight patients were being treated for CPP, two had palmoplantar psoriasis and one had whole-body psoriasis including palm and sole involvement. None of the patients have experienced adverse outcomes with SC infliximab during a mean follow-up time of 13 months. Dermatology Life Quality Index (DLQI) and Psoriasis Area and Severity Index (PASI) on both IV and SC infliximab were comparable. One patient had a high DLQI of 8 on SC infliximab, but her symptoms were localised to her feet and felt to represent a flare of chemotherapy-induced peripheral neuropathy. She reported a preference for the SC route. July 2007 PASI 47.0 May 2023 PASI 0.9 DLQI 0 April 2024 PASI 0 DLQI 0 September 2008 PASI 26.2 April 2024 PASI 1.4 DLQI 0 August 2024 PASI 1.4 DLQI 0 May 2016–September 2020, recommenced January 2021 PASI 20.9 (2015) October 2023 PASI 0.4 DLQI 2 March 2024 PASI 0 DLQI 8 2010 PASI 15.4 January 2024 PASI 0 DLQI 0 June 2024 PASI 0 DLQI 0 June 2008 L palm 100% R palm 100% R sole 80% L sole 75% January 2023 L palm 40% 1/2/2 R palm 20% 1/2/2 R and L sole 0% DLQI 1 July 2024 L palm 25% R palm 10% R and L sole 10% All 1/1/1 DLQI 0 July 2014 Baseline PASI Palms mild erythema and dryness Soles severe erythema, pustules, desquamation R 70%, L 60% April 2023 R palm clear L palm 5% erythema 1 thickness 1 scaling 1 R and L sole 5% DLQI 4 May 2024 Minimal scale palms R and L sole 5% DLQI 3 March 2009 Palms and soles 100% April 2023 PASI 0 DLQI 0 September 2024 PASI 0 DLQI 0 January 1999 PASI 28.2 January 2024 PASI 1.2 DLQI 0 September 2024 PASI 1.2 DLQI 0 January 2000 PASI 22.2 February 2024 PASI 0 DLQI 0 October 2024 PASI 1.2 DLQI 2 March 2018 PASI 19.3 November 2023 PASI 0 DLQI 0 June 2024 PASI 0 DLQI 0 August 2005 PASI 23.2 May 2023 PASI 0 DLQI 0 September 2024 PASI 0 DLQI 0 We offered 10 further patients on IV infliximab to switch to SC administration. Several reasons for reluctance to switch were cited, including enjoying the social aspect of the IV infusions, concerns about loss of efficacy with SC administration, anxiety around medication handling and storage and simply being content with the current route. Though our findings are limited by small patient numbers and a short follow-up time, they support SC infliximab as a safe and effective alternative to IV infliximab. The authors have nothing to report. Consent was obtained from the patients. C.L., K.G. and B.S.D. have no conflicts of interest to declare. P.F. has received fees, honoraria, grants and/or research funding as a speaker, investigator, advisory board member and/or consultant for Johnson & Johnson Innovative Medicine (Janssen). The data that support the findings of this study are available from the corresponding author upon reasonable request.