Prolonged tioguanine therapy for IBD well tolerated, effective in maintenance setting
Use of tioguanine for at least 12 months appears to be effective in the maintenance treatment of inflammatory bowel disease (IBD), and while adverse events are common, most are clinically tolerable, according to a recent study.
The study population comprised 274 tioguanine-treated IBD patients (median age at tioguanine initiation, 43 years; 63 percent female; 68 percent had Crohn’s disease). Median duration of treatment was 51 months, with median tioguanine dosage being 20 mg/d. There were 1,567 patient-years of follow-up.
Clinical effectiveness (defined as treatment response without [re]initiation of corticosteroids, concurrent biological therapy or surgical intervention) at 6 months was documented in 66 percent of patients, while sustained clinical effectiveness for 12 months was reported in 51 percent. Treatment was tolerable in most patients (79 percent).
Adverse events occurred in 41 percent of patients, including 5 percent who developed events graded as severe. Three patients had infection requiring hospitalization, while eight had skin cancer (two melanomas). Asymptomatic nodular regenerative hyperplasia of the liver occurred in two out of 52 patients with liver biopsies, and portal hypertension was recorded in three, including one case potentially associated with tioguanine.
Clinical effectiveness correlated with 6‐thioguanine nucleotide threshold concentrations >682 pmol/8×108 RBC (p<0.05).
In light of the findings, researchers stressed that the therapeutic benefit of tioguanine needs to be balanced with associated toxicity when considering a role for this thiopurine‐derivative in IBD treatment.