P354 A prospective randomised study: 2 mg/kg/d of azathioprine is an appropriate dosage for Chinese patients with Crohn’s disease
Y. Zhang*, J. Xia, Q. Cao
Sir Runrun Shaw Hospital, Zhejiang University School of Medicine, Department of Gastroenterology, Hangzhou, China
Azathioprine (AZA) is widely used in Crohn’s disease (CD) patients with a recommended dosage, 2–2.5mg/kg/d, for Westerners. Asian patients are suggested with a lower dosage. However, many clinicians reported a poor efficacy. Our prospective study aims to find a safe dosage providing the best efficacy for Chinese CD patients.
From 2012 to 2014, 50 Chinese patients with active CD were enrolled and randomly divided into group A (AZA 1 mg/kg/d) and group B (AZA 2 mg/kg/d). The combination of corticosteroids and AZA was the initial treatment and the steroids were tapered. We reassessed the Crohn’s Disease Activity Index (CDAI) on week 12, 24, and 48; examined the level of 6-thioguanine nucleotides (6-TGN) on week 12; and analysed the complete remission (CR) rate and the response rate with intent-to-treat (ITT) analysis and per-protocol (PP) analysis. Meanwhile, we evaluated the adverse events and the recurrence rate in both groups.
The CR rates and the response rates between the 2 groups on week 12 showed no significant difference. On week 24, the CR rate was significantly different (ITT p = 0.011; PP p = 0.027), whereas the response rate was different by ITT analysis (ITT p = 0.042; PP p = 0.112). On week 48, the CR rate and response rate in group B (ITT 50.0% and 59.1%; PP 57.9% and 68.4%) were significantly higher than those in group A (ITT 13.0% and 17.4%; PP 16.7% and 22.2%) (p < 0.05). The 6-TGN concentration were 209.78 ± 123.16 and 385.00 ± 118.40 pmol/8 × 108 RBC respectively in group A and B (p = 0.024). Further, 1 pancreatitis, 1 arthritis, and 2 myelosuppression as adverse events happened in group A, whereas in group B, 1 arthritis and 2 myelosuppression events happened. There was no significant difference in the incidence of adverse events between the 2 groups (p = 1.000). The recurrence rate in group A (26.1%) was significantly higher than that in group B (4.5%) (p = 0.042).
We found that 2 mg/kg/d is a more appropriate dosage of AZA than 1mg/kg/d is for Chinese CD patients with a high efficacy rate, a low recurrence rate, and no ascent in adverse events.