Thioguanine is effective as maintenance therapy for inflammatory bowel disease: a prospective multicentre registry study

BACKGROUND AND AIMS

Thioguanine is a well-tolerated and effective therapy for inflammatory bowel disease (IBD) patients. Prospective, effectiveness data are needed to substantiate the role of thioguanine as a maintenance therapy for IBD.

METHODS

IBD patients, who previously failed azathioprine or mercaptopurine, and initiated thioguanine were prospectively followed for 12 months starting when corticosteroid-free clinical remission was achieved (HBI ≤ 4 or SCCAI ≤ 2). Primary endpoint was corticosteroid-free clinical remission throughout 12 months. Loss of clinical remission was defined as SCCAI > 2 or HBI > 4, need of surgery, escalation of therapy, initiation of corticosteroids or study discontinuation. Additional endpoints were adverse events, drug survival, physician global assessment (PGA) and quality of life (QoL).

RESULTS

Sustained corticosteroid-free clinical remission at month 3, 6 or 12 months was observed in 75 (69%), 66 (61%) and 49 (45%) of 108 patients, respectively. Thioguanine was continued in 86 patients (80%) for at least 12 months. Loss of response (55%) included escalation to biologicals in 15%, corticosteroids in 10% and surgery in 3%. According to PGA scores, 82% of patients were still in remission after 12 months and QoL scores remained stable. Adverse events leading to discontinuation were reported in 11%, infections in 10%, myelo- and hepatotoxicity each in 6% and portal hypertension in 1% of patients.

CONCLUSION

Sustained corticosteroid-free clinical remission over 12 months was achieved in 45% of IBD patients on monotherapy with thioguanine. A drug continuation rate of 80%, together with favourable PGA and QoL scores, underlines the tolerability and effectiveness of thioguanine for IBD.