P0627Outcomes of autologous hematopoietic stem cell transplantation in patients with refractory Crohn’s Disease: a single-center retrospective case series

Abstract Background Despite advances in biological therapies and small-molecule agents, a subset of patients with Crohn’s disease (CD) remains or becomes refractory to all available treatments. Emerging evidence indicates that autologous hematopoietic stem cell transplantation (HSCT) may offer a viable therapeutic option for carefully selected patients with treatment-refractory CD. Real-world data on the long-term efficacy and safety of HSCT in this population remain important due to the rarity of its use. Methods We retrospectively analyzed the outcomes of all CD patients who underwent autologous HSCT for treatment-refractory disease at our IBD referral center between 2011 and 2023. All included patients had severe, refractory CD and were deemed unsuitable for surgical intervention due to extensive small bowel involvement. All patients underwent reassessment with ileocoloscopy 12 months after HSCT. Results We included 24 patients (15 females (62.5%), median age at HSCT 31 27-34.5 years, median disease duration 13 9.75-17.25 years) underwent stem cell mobilization and collection, of whom 23 patients proceeded to HSCT (Table 1). All patients had extensive small bowel disease and 14 patients (58.3%) had concomitant perianal involvement. Seven patients (29.2%) were actively smoking at HSCT. After a mean follow-up of 92.3 114.61; 65.95-138.39 months, 9 patients (37.5%) were still free of luminal and perianal disease activity without therapy. Endoscopic CD recurrence, defined as total SES-CD 3, occurred in 15 patients (65.2%), after a mean of 26.1 7; 5-25 months (Figure 1), necessitating restart of advanced therapy. Fourteen patients (60.1%) had to restart treatment, eventually regaining endoscopic remission in almost all patients (92.9%) with both, previously used and new biologicals. In 7 patients (30.4%) more than one relapse occurred. Surgery was needed in 7 patients (30.4%), with ileo- or colostomy in 3 patients (13.0%). No factors associated with the risk of recurrence could be identified. Infectious complications in the peri-HSCT period were seen in 12 patients (52.2%). No deaths nor secondary malignancies were documented. Conclusion Findings from our single-center cohort indicate that autologous HSCT is a relatively safe and effective therapy for inducing and maintaining endoscopic remission in carefully selected CD patients with a highly refractory phenotype. Although many patients experienced disease relapse, most regained response to previously ineffective medical therapies, suggesting that HSCT may modify disease biology and restore treatment susceptibility. Conflict of interest: Dr. Geebelen, Gitte: No conflicts. Van Besien, Arnout: No conflict of interest Van Ham, Jonas: No conflict of interest D’hooghe, Anna-Teresa: No conflicts. 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. 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. Verstockt, Bram: Research support from AbbVie, Biora Therapeutics, Celltrion, Landos, Pfizer, Sanofi, Sossei Heptares/Nxera and Takeda. Speaker’s fees from Abbvie, Agomab, Alfasigma, Biogen, Bristol Myers Squibb, Celltrion, Eli Lily, Falk, Ferring, Galapagos, Materia Prima, Johnson and Johnson, Pfizer, Sandoz, Takeda, Tillots Pharma, Truvion and Viatris. Consultancy fees from Abbvie, Alfasigma, Alimentiv, Anaptys Bio, Applied Strategic, Astrazeneca, Atheneum, BenevolentAI, Biora Therapeutics, Boxer Capital, Bristol Myers Squibb, Domain Therapeutics, Eli Lily, Galapagos, Guidepont, Landos, Merck, Mirador Therapeutics, Mylan, Nxera, Inotrem, Ipsos, Johnson and Johnson, Pfizer, Sandoz, Sanofi, Santa Ana Bio, Sapphire Therapeutics, Sosei Heptares, Takeda, Tillots Pharma and Viatris. Stock options Vagustim and Thethis Pharma. Dierickx, Daan: No conflict of interest Vermeire, Séverine: Grant: AbbVie, Pfizer, Takeda, J & J, Galapagos Personal Fees: AbbVie - AbolerIS Pharma - AgomAb - Alimentiv - Arena Pharmaceuticals - AstraZeneca - Avaxia- BMS - Boehringer Ingelheim - Celgene - CVasThera - Dr Falk Pharma - Ferring - Galapagos - Genentech-Roche - Gilead - GSK - Hospira - Imidomics - Janssen - J & J - Lilly - Materia Prima - MiroBio - Morphic - MrMHealth - Mundipharma - MSD - Pfizer - Prodigest - Progenity - Promakhos Therapeutics - Prometheus - Robarts Clinical Trials - Second Genome - Shire - Surrozen - Takeda - Theravance - Tillots Pharma AG - Zealand Pharma - Other: AbbVie, MSD, Takeda, Ferring, Genentech/Roche, Shire, Pfizer Inc, Galapagos, Mundipharma.