Thiopurine Monotherapy Is Effective in Maintenance of Mild-Moderate Inflammatory Bowel Disease

Thiopurines Have Sustained Long-term Effectiveness in Patients with Inflammatory Bowel Disease, Which is Independent of Disease Duration at Initiation: A Propensity Score Matched Analysis

BACKGROUND AND AIMS

Thiopurines are viable option for the treatment of inflammatory bowel disease [IBD] in resource-limited countries. However, data on the effect of disease duration at thiopurines initiation on long-term effectiveness are limited.

METHOD

We performed a propensity matched analysis of a retrospective cohort of patients with ulcerative colitis [UC] and Crohn's disease [CD]. Patients initiated on thiopurines early in the disease course [≤2 years] were compared with those started late [>2 years]. Effectiveness was defined as no requirement for hospitalisation, anti-tumour necrosis factor [TNF] agents, or surgery, and minimum steroid requirement [≤1 steroid course in 2 years] during follow-up.

RESULTS

A total of 988 [UC: 720, CD: 268] patients were included (male: 665 [60.8%], median age: 40 [32-51] years, median follow-up: 40 [19-81] months). Overall effectiveness at 5 and 10 years was 79% and 72% in UC, and 69% and 63% in CD, respectively. After propensity score matching, there was no difference in 5- and 10-year effectiveness between early and late thiopurine initiation groups either for UC [81% and 80% vs 82% and 74%; p = 0.92] or CD [76% and 66% vs 72% and 51%, p = 0.32]. Male sex for UC (negative: hazard ratio [HR]: 0.67, 95% confidence interval [CI): 0.45-0.97; p = 0.03), and ileal involvement [positive: HR: 3.03, 95% CI: 1.32-6.71; p = 0.008], steroid-dependent disease [positive: HR: 2.70, 95% CI: 1.26-5.68; p = 0.01] and adverse events [negative: HR: 0.47, 95% CI:0.27-0.80; p = 0.005] for CD were predictors of thiopurine effectiveness.

CONCLUSION

Thiopurines have sustained long-term effectiveness in both UC and CD. However, early thiopurine initiation had no better effect on long-term disease outcome compared with late initiation.

Precision medicine and drug optimization in adult inflammatory bowel disease patients

Inflammatory bowel diseases (IBD) encompass two main entities including ulcerative colitis and Crohn's disease. Although having a common global pathophysiological mechanism, IBD patients are characterized by a significant interindividual heterogeneity and may differ by their disease type, disease locations, disease behaviours, disease manifestations, disease course as well as treatment needs. Indeed, although the therapeutic armamentarium for these diseases has expanded rapidly in recent years, a proportion of patients remains with a suboptimal response to medical treatment due to primary non-response, secondary loss of response or intolerance to currently available drugs. Identifying, prior to treatment initiation, which patients are likely to respond to a specific drug would improve the disease management, avoid unnecessary side effects and reduce the healthcare expenses. Precision medicine classifies individuals into subpopulations according to clinical and molecular characteristics with the objective to tailor preventative and therapeutic interventions to the characteristics of each patient. Interventions would thus be performed only on those who will benefit, sparing side effects and expense for those who will not. This review aims to summarize clinical factors, biomarkers (genetic, transcriptomic, proteomic, metabolic, radiomic or from the microbiota) and tools that could predict disease progression to guide towards a step-up or top-down strategy. Predictive factors of response or non-response to treatment will then be reviewed, followed by a discussion about the optimal dose of drug required for patients. The time at which these treatments should be administered (or rather can be stopped in case of a deep remission or in the aftermath of a surgery) will also be addressed. IBD remain biologically complex, with multifactorial etiopathology, clinical heterogeneity as well as temporal and therapeutic variabilities, which makes precision medicine especially challenging in this area. Although applied for many years in oncology, it remains an unmet medical need in IBD.

Classic drugs in the time of new drugs: real-world, long-term outcomes of thiopurine monotherapy in 1016 patients with inflammatory bowel disease

BACKGROUND

Thiopurines remain recommended as maintenance therapy in patients with inflammatory bowel disease (IBD). Despite their widespread use, long-term effectiveness data are sparse and safety is an increasingly debated topic which thwarts proper delineation in the current IBD treatment algorithm.

AIMS

To document effectiveness and safety of thiopurine monotherapy in patients with IBD, using the population-based IBD South-Limburg (IBDSL) cohort METHODS: All patients starting thiopurine monotherapy as maintenance between 1991 and 2014 were included. Therapy was defined as effective if there was no escalation to biologicals, no course of corticosteroids, no surgery and no hospitalisation for active disease during treatment. Long-term effectiveness was assessed by adjusting for differences in follow-up using Kaplan-Meier analyses. Mid- to long-term safety regarding cancer incidence and clinically relevant liver disease was documented.

RESULTS

In total, 1016 patients (643 Crohn's disease [CD]; 373 ulcerative colitis [UC]) received thiopurine monotherapy at a median of 15.2 (Q1-Q3 4.2-48.5) months after diagnosis. During follow-up, effectiveness rates at 1, 5 and 10 years were 64%, 45%, 32%, respectively, in CD and and 66%, 41%, 36%, respectively in UC. No statistically significant differences in effectiveness were observed after stratification for era of initiation (pre-biological vs biological, CD: p = 0.56; UC: p = 0.43). Sixteen non-melanoma skin cancers (incidence rate [IR] 3.33/1000 PY), five lymphomas (IR 1.04/1000 PY) and one urinary tract cancer (IR 0.21/1000 PY) were recorded. Two cases of portal hypertension were identified.

CONCLUSION

In real-world practice, thiopurine monotherapy remains effective, safe and durable for patients with CD or UC, including in the era of biologics.