Abstract Background Subcutaneous (SC) infliximab (IFX) CT-P13 offers an alternative to intravenous (IV) administration, but evidence in patients maintained on optimized IV dosing remains limited (1). The ongoing AMARETTO trial (NCT06113913) investigates whether switching to weekly SC IFX 120 mg is associated with better outcomes than bi-weekly SC dosing in patients with inflammatory bowel disease (IBD) and prior optimized IV therapy. This analysis investigates the baseline patient characteristics linked to willingness to switch from optimized IV to SC IFX. Methods This multicentre, randomized, open-label superiority trial includes adult IBD patients treated with optimized IV IFX who are in steroid-free clinical (PRO-2) and biological remission (CRP 10 mg/L and faecal calprotectin 250 µg/g). Eligible patients could choose to continue optimized IV IFX (IV comparison group) or switch to SC IFX. Those switching were randomized 1: 1 to open-label weekly (SC intervention) or bi-weekly 120 mg SC IFX (SC comparison). Primary endpoint is the proportion of patients maintaining steroid-free clinical and biological remission at week 52 without treatment optimization. Here, we focus on the secondary outcomes assessing baseline characteristics associated with willingness to switch to SC therapy and patient’s reported reasons for (not) switching at the time of decision. Results Patient recruitment is closed, with 275 patients enrolled between May 2024 and October 2025. Baseline characteristics were comparable between those willing and unwilling to switch to SC (Table 1). The only significant difference was age (in years), with patients willing to switch being younger than those continuing IV treatment (Figure 1). Main reasons for switching were: anticipated reduction in hospital visits (89/149, 60%), time savings (86/149, 58%), greater independence from the hospital (23/149, 11%), altruistic research motivation (6/149, 3%), and difficulties with IV administration (6/149, 3%). Main reasons for not switching were fear of: change (65/126, 52%), disease relapse (30/126, 24%), non-adherence (12/126, 10%), reduced contact with health care professionals (9/126, 7%), and needles (8/126, 6%). Conclusion Apart from younger age being associated with greater willingness to switch, baseline characteristics did not differ between patients choosing SC versus continuing optimized IV IFX. Motivations for switching were mainly practical, reflecting a desire to reduce hospital visits and save time, while reluctance was primarily driven by fear of change and concerns about disease control. The AMARETTO trial will further clarify whether weekly SC dosing offers superior outcomes compared to bi-weekly SC IFX in this population. Reference: 1. Fierens L, Liefferinckx C, Hoefkens E, et al. Introduction of Subcutaneous Infliximab CT-P13 and Vedolizumab in Clinical Practice: A Multi-Stakeholder Position Statement Highlighting the Need for Post-Marketing Studies. J Crohn’s Colitis 2022;16: 1059–1069. Funding: Celltrion Healthcare Conflict of interest: Dr. Moens, Annick: None Holvoet, Tom: None Guedelha Sabino, João: Speaker’s fees: Lilly, Pfizer, Abbvie, Ferring, Falk, Takeda, Janssen, Fresenius, and Galapagos. Consultancy fees: Takeda, Pfizer, Janssen, Ferring, Fresenius, Abbvie, Galapagos, Celltrion, Pharmacosmos, and Pharmanovia. Research support: Galapagos, Viatris, and Eurogenerics. JS is supported by a Senior Clinical researcher grant from the Research foundation – Flanders. Bossuyt, Peter: Grant support for research from AbbVie, EG Consulting fee from AbbVie, Bristol Meyers Squibb, CIRC, Galapagos, Janssen, Jeito capital, Lilly, Pentax, Pfizer, PSI-CRO, Roche, Takeda, Tetrameros Speakers fee from AbbVie, AMC ICP, Amgen, Bristol Myers Squibb, Celltrion, Dr Falk Benelux, EG, Galapagos, Globalport, Lilly, Medtalks, Materia Prima, Pentax, Springer Media Lobatón Ortega, Triana: Grant: Abbvie, Ferring, Viatris, MSD, EG, Mundipharma, Biogen, Janssen, Pfizer, Takeda, Galapagos, Afasigma and Sandoz. Personal Fees: Speaker fees from MSD, Abbvie, Janssen, Amgen, Fresenius Kabi, Galapagos, Viatris, Ferring, Celltrion, Alfasigma, Lilly and Takeda. Consultancy fee from Janssen, Galapagos, Alfasigma, Amgen, Bristol Myers, Squibb Fresenius Kabi, Takeda and Abbvie Cremer, Anneline: Consulting fee from AbbVie, Takeda, Alfasigma, Johnson & Johnson Speakers fee from AbbVie, Takeda, Alfasigma, Johnson & Johnson, Celltrion, Galapagos, Eli Lilly, Pfizer Caenepeel, Clara: Speaker fee: Abbvie, Alfasigma Consultancy fee: Alfasigma, Janssen Posen, Annelies: none Thienpont, Clara: No conflict of interest Willandt, Barbara: Lecture fees/Consultancy: Johnson & Johnson, Amgen, Abbvie, VIatris, Celltrion, , Takeda, Alfasigma, Lilly, Biogen. Capirchio, Lena: Research grants: Abivax, Johnson & Johnson, Celltrion Education and Research Grants for my department: Abbvie, Celltrion, EG, Johnson & Jonhson, Lilly, Takeda Personal Fees for conferences: EG Jauregui-Amezaga, Aranzazu: I declare that I have no personal financial conflicts of interest related to my scientific activities. Any research funding received from Takeda, Johnson & Johnson, and AbbVie has been allocated to the research group to which I belong and has been used exclusively to support institutional or group-based research initiatives, with no personal financial benefit. Lambrecht, Guy: none Baert, Filip J.: Grant: AbbVie, Amgen, EG, J&J, Takeda. Personal Fees: AbbVie, Abivax, Alpha Sigma, Arena, BMS, , Celltrion, Eli Lilly, Falk, Ferring, Fresenius, Galapagos, J&J, Pfizer, Sandoz, Takeda, Vifor. Deprez, Nele: No conflict of interest Peeters, Harald: Disclosures – conflicts of interest - Financial support for research: Abbvie, Mylan, Amgen, Sandoz, Takeda - fees: Janssen, Takeda, Abbvie - Consultancy fees: Janssen, Fresenius-Kabi, Abbvie, Galapagos Reenaers, Catherine: Grant: Ferring, Janssen, Takeda, Fresenius, Biogen Personal Fees: Ferring, Janssen, Takeda, Fresenius, Abbvie, Galapagos, Pfizer, Celltrion, Thermofisher, BMS, Lilly, Thermofisher Vanden Branden, Stijn: None De Rechter, Jolien: None Arijs, Ingrid: None Dreesen, Erwin: Other: Erwin Dreesen received consultancy fees from Alimentiv and argenx, lecture fees from Celltrion and Galapagos, and financial support from Celltrion, Janssen, Pfizer, Prometheus Biosciences, R-Biopharm, and Sandoz, outside the submitted work, with all honoraria/fees being paid to KU Leuven and not to any personal account of Erwin Dreesen. Ferrante, Marc: Research grants from AbbVie, EG Pharma, Celltrion, Janssen, Pfizer, Takeda and Viatris Consultancy fees from AbbVie, AgomAb Therapeutics, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Janssen-Cilag, MRM Health, Merck Sharp and Dohme, Pfizer, Takeda and ThermoFisher Speakers’ fees from AbbVie, Biogen, Boehringer Ingelheim, Dr Falk Pharma, Ferring, Janssen-Cilag, Merck Sharp and Dohme, Pfizer, Takeda, Truvion Healthcare and Viatris
Moens et al. (Thu,) studied this question.