Monotherapy with thiopurines in stricturing Crohn's disease: A real-life experience from low- and middle-income countries.

Background: Stricturing Crohn's disease (CD) is difficult to manage medically with limited treatment options, anti-tumor necrosis factor (TNF) therapy being the first-line therapy. Although thiopurines are also recommended first-line treatment option for maintenance of remission in steroid-dependent CD, evidence on their use in stricturing CD is lacking. We evaluated the efficacy of azathioprine (AZA) in patients with stricturing CD.

Methods: In this retrospective cohort study (January 2005 to July 2020), patients with stricturing CD who were managed with AZA as a primary therapy for at least 6 months, and had a follow-up of at least 6 months after AZA initiation were included. Disease characteristics, complications, long-term response, and adverse events were noted.

Results: One hundred and fifteen patients were included (mean age 33.8±14 years, 67.8% males, median disease duration 98 months [IQR: 60-158], median follow-up duration 60 months [IQR: 50-96]). 46.1% (n=53) patients had significant anemia at presentation, and 73% (n=84) had isolated small bowel involvement. Median dose of AZA was 100 mg (equivalent to 1.5 mg/kg). Median therapy and follow-up duration (after AZA initiation) was 17 (IQR: 9-42) and 33 months (IQR 18-60), respectively. The cumulative probability of maintaining response without treatment failure at 1, 2, and 5 years was 73.1%, 40.7%, and 18.5%, respectively. Among patients with AZA failure, 15.6% received methotrexate, 13% received anti-TNFs, and 9.5% underwent surgery. Significant anemia (<10 g/dL) at presentation and steroid dependence predicted AZA failure. 31.3% patients experienced adverse events, commonest being leukopenia (n=29, 25.2%).

Conclusion: Azathioprine demonstrated good short-term and modest long-term response rates in patients with stricturing CD.