Repeated Thiopurine metabolite monitoring and dose optimization tied to remission of IBD

Singapore: Recent study by Jia Qi Yeo and team found, metabolite monitoring of thiopurine therapy against inflammatory bowel disease (IBD) enables rapid dose optimization or therapy escalation for non-responders.

The findings of this study were published in the Journal of Gastroenterology and Hepatology.

For the preservation of steroid-free remission (SFR) in IBD, thiopurines are advised. There is little data on the therapeutic and financial advantages of thiopurine metabolite monitoring, which is still new in Singapore. 

At the outpatient IBD Center of Singapore General Hospital, a retrospective observational study was carried out. 90 patients (50 with Crohn's disease and 40 with ulcerative colitis) treated with weight-based thiopurine dosages for 4 weeks with baseline MM between 2014 and 2017 were followed up for a year. Metabolite levels were measured before and after the initial action to optimize the therapy. SFR, the avoidance of surgery or therapy escalation, the use of medical resources, and direct medical expenses were all outcomes that were evaluated.

The key highlights of this study were as follows:

1. 40% of them had initial metabolite levels within the therapeutic range, 31.1% had levels that were below the therapeutic range, 21.1% had levels that were above the therapeutic range, and 7.8% had shunters.

2. Following dose modification, repeated MM enabled 67.2% of patients to reach therapeutic levels after a year.

3. Overall, 87.8% of patients reached SFR, and 90% underwent no surgery or therapeutic escalation.

4. Even though there were more outpatient visits and laboratory tests with MM, the median annual total cost of care only slightly rose.

In conclusion, the clinical usefulness of MM in maximizing thiopurine therapy for Singaporean IBD patients has been proven in this study. Repeated MM can help with dose adjustment so that therapeutic metabolite levels can be reached. Additionally, MM was not linked to considerably greater expenses or resource use for medical treatment. The clinical advantages of MM, such as results on mucosal healing, and the potential economic savings of MM, particularly for thiopurine/anti-TNF combo therapy, must be confirmed in future cost-effectiveness studies.

Reference: 

Yeo, J. Q., Cheen, H. H. M., Wong, A., Lim, T. G., Chowbay, B., Leong, W. F., Wang, C., Salazar, E., Chan, W. P. W., Kong, S. C., & Ong, W. C. (2022). Clinical utility of thiopurine metabolite monitoring in inflammatory bowel disease and its impact on healthcare utilization in Singapore. In JGH Open. Wiley. https://doi.org/10.1002/jgh3.12798