P508 Safety and efficacy of combining biological therapies together or with small molecules in patients with inflammatory bowel disease: A retrospective multicentre national observational case series study

Abstract Background Few data are available regarding the combination of biological therapies (anti-TNF, anti-integrin, anti-interleukins (IL4, 12/23, 17A, 23)) or with a small molecule in patients with IBD. We here report the safety and efficacy of combining these drugs through a national retrospective multicenter case series. Methods Cases were extracted from local databases within the last 3 years. Combined therapy was defined as the concomitant use for a minimum of 1 day of 2 biologics or 1 biologic with a small molecule. Patients’ demographics, disease’ characteristics and types of combined therapies were recorded. Safety was defined as the occurrence of any serious adverse event (SAE): serious infection, opportunistic infection, any hospitalisation, cancer and death, whereas the efficacy of combination was clinically appreciated by physicians. Results From 8 centres, 23 combined therapies were observed in 19 IBD patients (74% Crohn’s disease, 21% ulcerative colitis and 5% IBD type unclassified). Median age at combination was 43.0 years ([IQR]: 31.5–59.0). Seventeen patients presented with a minimum of 1 concomitant IMID (ankylosing spondylitis (n = 11), psoriasis or psoriatic arthritis (n = 5) and other conditions (n = 5)). Reasons for starting a combination were active IBD (57%), another active IMID (30%) or both (13%). Anti-TNF and anti-integrin were combined in 11 cases, anti-TNF and anti-ILs in 5, anti-integrin and anti-ILs in 4 and other combinations in 3 (anti-TNF+rituximab+methotrexate; anti-IL4+anti-IL12/23; anti-IL12/23+methotrexate+leflunomide). The median duration of combined therapies was 5 months ([IQR]: 2–9). During 15.8 patients/years of combined therapy, 11 adverse events (AE) including 9 SAE were recorded in 8 patients. Eight infections were reported with various combinations: anti-TNF and anti-IL in 4 cases, anti-TNF and anti-integrin in 3 and anti-TNF+rituximab+methotrexate in 1. Two infections (both anti-TNF+ anti-integrin) were graded severe leading to hospitalisation, 6 were graded mild or moderate. Cancer and death were not observed. After combined therapy, IBD disease activity was clinically improved in 44% and remained stable in 50% of patients, whereas clinical improvement of IMID was observed in 25% of patients. Overall, the combination of treatments was withdrawn due to ineffectiveness or serious adverse events in 39% and 4%, respectively. Conclusion In our experience, the combination of biologics in patients with IBD ±. an