Real-world NUDT15 genotyping and thiopurine treatment optimization in inflammatory bowel disease: a multicenter study.

BACKGROUND: This study evaluated the effectiveness of NUDT15 codon 139 genotyping in optimizing thiopurine treatment for inflammatory bowel disease (IBD) in Japan, using real-world data, and aimed to establish genotype-based treatment strategies. METHODS: A retrospective analysis of 4628 IBD patients who underwent NUDT15 codon 139 genotyping was conducted. This study assessed the purpose of the genotyping test and subsequent prescriptions following the obtained results. Outcomes were compared between the Genotyping group (thiopurine with genotyping test) and Non-genotyping group (thiopurine without genotyping test). Risk factors for adverse events (AEs) were analyzed by genotype and prior genotyping status. RESULTS: Genotyping test for medical purposes showed no significant difference in thiopurine induction rates between Arg/Arg and Arg/Cys genotypes, but nine Arg/Cys patients opted out of thiopurine treatment. In the Genotyping group, Arg/Arg patients received higher initial doses than the Non-genotyping group, while Arg/Cys patients received lower ones (median 25 mg/day). Fewer AEs occurred in the Genotyping group because of their lower incidence in Arg/Cys cases. Starting with < 25 mg/day of AZA reduced AEs in Arg/Cys patients, while Arg/Arg patients had better retention rates when maintaining ≥ 75 mg AZA. Nausea and liver injury correlated with thiopurine formulation but not dosage. pH-dependent mesalamine reduced leukopenia risk in mesalamine users. CONCLUSIONS: NUDT15 codon 139 genotyping effectively reduces thiopurine-induced AEs and improves treatment retention rates in IBD patients after genotype-based dose adjustments. This study provides data-driven treatment strategies based on genotype and identifies risk factors for specific AEs, contributing to a refined thiopurine treatment approach.

Long-term effectiveness of ustekinumab comparable to antitumor necrosis factor agents in patients with Crohn's disease.

BACKGROUND: Ustekinumab (UST), an antibody against the p40 subunit of interleukin-12/23, has been proven to be effective in patients with Crohn's disease (CD). However, large, long-term comparative studies of UST against anti--tumor necrosis factor (TNF) agents are lacking. We compared the effectiveness of anti-TNF agents and UST in CD patients without prior use of biologics. METHODS: We used a large nationwide anonymized Japanese database containing administrative medical claims data and various related patient data. In a propensity score-matched cohort with similar clinical characteristics, 2-year effectiveness was compared between patients treated with infliximab or adalimumab (anti-TNF group) and those treated with UST (UST group). Primary outcomes were cumulative rates of hospitalization, surgery, and persistence. RESULTS: Among 53 540 CD patients, 7047 were extracted for eligibility, of which 5665 were treated with an anti-TNF agent and 1382 with UST. After propensity score matching, the cumulative hospitalization rates were comparable between anti-TNF and UST groups (P = 0.85; 25.3% vs 26.5% at 1 year, 33.8% vs 39.8% at 2 years). The cumulative surgery rates were also comparable between these groups (P = 0.46; 5.5% vs 5.1% at 1 year, 8.3% vs 8.4% at 2 years). The persistence rate at 1 year was higher in UST group (90.8% vs 92.5%), and that at 2 years was higher in anti-TNF group (81.2% and 74.6%); however, there was no significant difference in the cumulative persistence rate (P = 0.55). CONCLUSIONS: Anti-TNF agents and UST appear to have comparable effectiveness for CD patients without prior use of biologics.