Long-term results of mycophenolate mofetil vs. azathioprine use in individuals with autoimmune hepatitis

Background & Aims: We have shown previously that mycophenolate mofetil (MMF) might be used as first-line treatment instead of azathioprine (AZA) in individuals with autoimmune hepatitis (AIH). Herein, we present our long-term prospective data on response and outcome after first-line therapy with MMF in treatment-naive individuals with AIH, as similar data are missing.Methods: During the 21 years of the study, 292 individuals with AIH were included (females: 213; median age: 59 [17-85] years). Patients received either prednisolone 0.5-1 mg/kg/day alone (n = 19) or in combination with AZA 1-2 mg/kg/day (n = 64) or MMF (n = 183). The tapering schedule of prednisolone was identical between groups. We assessed the rates of complete biochemical response (CBR) at 6 months, 12 months, and the end of follow-up; non-response (4 weeks of treatment); CBR off prednisolone; adverse effects; CBR off treatment; histological remission; and overall and liver-related mortality between the AZA and MMF groups.Results: The MMF group had lower non-response (p = 0.02) and higher CBR rates at 12 months (86 vs. 71.8%; p <0.05) and the end of follow-up (96 vs. 87.2%; p = 0.03) than the AZA group. Treatment change was more frequent in the AZA group (43.7 vs. 11%; p <0.001), mostly because of intolerance, whereas MMF was proven safe (serious complications 3.8 vs. 18.8%; p = 0.0003). MMF-treated patients were more frequently eligible to stop immunosuppression according to the guidelines (p <0.05). Cirrhosis at diagnosis, age at diagnosis >60 years, and longer disease duration were independent predictors of liver-related mortality.Conclusions: MMF seems an efficient alternative first-line treatment option for AIH, bearing lower non-response at 4 weeks and higher CBR rates at 12 months and the end of follow-up than AZA. In addition, MMF was proven to be safe, leading more frequently to the eligibility for stopping immunosuppression according to the guidelines.Impact and implications: For more than 40 years, azathioprine (AZA) has been considered the standard treatment for in-duction and maintenance of response in autoimmune hepatitis (AIH). However, treatment usually needs to be maintained for life, as relapses are common after AZA cessation. Therefore, alternative treatment options are needed. Herein, we showed that the use of mycophenolate mofetil (MMF) as an alternative first-line immunosuppressant was much more efficient in the long-term than AZA as attested by the lower non-response rates at 4 weeks and higher response rates at 12 months and the end of follow-up. Moreover, AZA-treated patients were more prone to change treatment because of intolerance, whereas MMF-treated patients were more often eligible to achieve treatment withdrawal.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of European Association for the Study of the Liver (EASL). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).