Subcutaneous vedolizumab interval extension in inflammatory bowel disease patients: a case series.

Subcutaneous vedolizumab has demonstrated efficacy as a maintenance therapy in inflammatory bowel disease (IBD). However, data on the extension of subcutaneous vedolizumab injection intervals are lacking. Here, we present the first real-world data on subcutaneous vedolizumab interval extension in IBD patients. Nine patients (eight Crohn's disease patients and one ulcerative colitis patient) were included in the study. At interval extension (at baseline), all patients were in clinical and biochemical remission and requested an extension of their 2-weekly injection intervals due to side effects potentially related to subcutaneous vedolizumab. Patients increased their intervals to 3, 4, or 5 weeks. During a median follow-up of 10.0 months (IQR 6.5-19.5), no flare-ups were observed. After 6 months, median biochemical parameters remained stable compared to baseline levels (fecal calprotectin 24.0 µg/g [IQR 10.0-43.0] versus 28.0 µg/g [IQR 15.0-54.0], p = 0.553; C-reactive protein 3.4 mg/L [IQR 1.4-4.2] versus 3.1 mg/L [IQR 0.7-4.9], p = 0.172), while vedolizumab serum concentrations significantly decreased (22.0 µg/mL [IQR 20.0-33.0] versus 40.0 µg/mL [IQR 28.3-45.0], p = 0.018). After interval extension, almost all suspected vedolizumab-induced side effects disappeared within 6 months. Lengthening subcutaneous vedolizumab intervals in IBD patients in clinical and biochemical remission appears to be both effective and safe, potentially leading to substantial reductions in healthcare expenses.