Feasibility of Reduced Clinical Monitoring in Patients with Inflammatory Bowel Disease Treated with Thiopurine Therapy.

BACKGROUND: Outpatient visits and laboratory assessments are routinely scheduled every 3 to 4 months in thiopurine-treated patients with inflammatory bowel disease (IBD) to timely detect thiopurine-related adverse events (AEs). AEs that require therapy adjustment beyond 12 months of treatment are rare. AIM AND METHODS: This single-center prospective cohort study evaluated the safety of a reduced 6-monthly monitoring strategy in steroid-free patients with quiescent IBD on stable dose of azathioprine, mercaptopurine, or thioguanine monotherapy. The primary outcome was thiopurine-related AEs requiring therapy adjustments during a follow-up period of 24 months. Secondary outcomes included all AEs including laboratory toxicity, disease flares until 12 months, and the net monetary benefit from this strategy concerning IBD-related health care use. RESULTS: We enrolled 85 patients with IBD (median age 42 years, 61% Crohn's disease, 62% female), with a median disease duration of 12.5 years and median thiopurine treatment duration of 6.7 years. During follow-up, 3 patients (4%) ceased thiopurines due to AEs: recurrent infections, non-melanoma skin cancer, and gastrointestinal complaints (nausea, vomiting). At 12 months, 25 laboratory toxicities were observed (including 13% myelotoxicity, 17% hepatotoxicity); none required therapy adjustments and all were transient. A reduced monitoring strategy had a net benefit of €136 per patient. CONCLUSION: Three patients (4%) ceased thiopurine therapy due to thiopurine-related AEs, while no laboratory toxicity required therapy adjustments. Monitoring frequency of every 6 months seems feasible in patients with stable IBD on long-term (median duration > 6 years) maintenance thiopurine therapy and may contribute to reduced patient-burden and health care costs.

Limited added value of laboratory monitoring in thiopurine maintenance monotherapy in inflammatory bowel disease patients.

BACKGROUND: To timely detect myelotoxicity and hepatotoxicity, laboratory monitoring at 3-month intervals is advised throughout thiopurine maintenance treatment for IBD. However, reported incidence rates of myelotoxicity and hepatotoxicity in maintenance treatment are low. AIM: To assess incidence rates and clinical consequences of myelotoxicity and hepatotoxicity in thiopurine maintenance therapy after at least 1 year of thiopurine treatment. METHODS: Retrospective analysis of therapy adjustment for laboratory toxicity in adult IBD patients after 12 consecutive months of azathioprine (AZA) or mercaptopurine monotherapy (ie baseline) between 2000 and 2016. Incidence rates of laboratory toxicity (ie myelotoxicity [leucocyte count <4.0 × 10e9/L, and/or platelet count <150 × 10e9/L] and/or hepatotoxicity (gamma-glutamyltransferase [GGT], alkaline phosphatase [AP], ALT and/or AST above ULN, excluding isolated increased AST/AP]) and associated diagnostic procedures and complications were assessed. RESULTS: In total, 12,391 laboratory assessments were performed on 1132 patients (56% female, AZA 74%) during 3.3 years of median follow-up. Median monitoring frequency was 3.1 assessments/treatment year. Only 83/12,391 (0.7%) assessments resulted in therapy adjustment, dose reduction in 46 patients, cessation in 28 and allopurinol initiation in nine; risk of therapy adjustment was 1.9% per treatment year. Incidence rates of myelotoxicity were 7.1% (5.1% mild/1.8% moderate/0.1% severe) and hepatotoxicity 5.1% (3.8% mild/1.1% moderate/0.2% severe) per treatment year. Treatment-related complications with concurrent laboratory toxicity occurred in 12 patients (1.1%) and would not have been prevented by monitoring. CONCLUSION: Severe laboratory toxicity is uncommon after 1 year of thiopurine monotherapy at 4-month monitoring intervals. Therapy adjustments are rare after detection of laboratory toxicity. After 1 year of thiopurine monotherapy, laboratory monitoring may be lowered to less than a 4-month interval.

No Superiority of Tacrolimus Suppositories vs Beclomethasone Suppositories in a Randomized Trial of Patients With Refractory Ulcerative Proctitis.

BACKGROUND & AIMS: Ulcerative proctitis (UP) refractory to 5-aminosalicylic acid (5-ASA) suppositories is a challenge to treat, often requiring step up to immunomodulator or biological therapy. Topical tacrolimus is effective and safe in patients with refractory UP. However, it is not clear how tacrolimus suppositories fit into in the treatment algorithm of UP. METHODS: We performed a randomized controlled, double-blind study at 8 hospitals in the Netherlands and Belgium from 2014 through 2017. Eighty-five patients with refractory UP (65% women) were randomly assigned to groups given once daily tacrolimus suppositories (2 mg; n = 43) or beclomethasone (3 mg; n = 42) for 4 weeks. The primary outcome was clinical response (decrease in Mayo score of 3 or more). Secondary outcomes included clinical remission, endoscopic response and remission, adverse events and quality of life. Outcomes were compared using Fisher's exact test and Mann-Whitney U test. RESULTS: Proportions of patients with clinical responses were 63% in the tacrolimus group and 59% in the beclomethasone group (P = .812); proportions of patients in clinical remission were 46% and 38%, respectively (P = .638). Proportions of patients with an endoscopic response were 68% and 60% in the tacrolimus group and in the beclomethasone group (P = .636); proportions in endoscopic remission rates were 30% and 13%, respectively (P = .092) Median increases in the inflammatory bowel disease questionnaire score were 18.0 in the tacrolimus group and 20.5 in the beclomethasone group (P = .395). Adverse event rates did not differ significantly between groups. CONCLUSIONS: In a 4-week randomized controlled trial, tacrolimus and beclomethasone suppositories induce comparable clinical and endoscopic responses in patients with UP refractory to 5-ASA. There were no significant differences in adverse events rates. Tacrolimus and beclomethasone suppositories are therefore each safe and effective treatment options for 5-ASA refractory disease. EUDRACT 2013-001259-11; Netherlands Trial Register NL4205/NTR4416.

Real-life study of safety of thiopurine-allopurinol combination therapy in inflammatory bowel disease: myelotoxicity and hepatotoxicity rarely affect maintenance treatment.

BACKGROUND: Low-dose thiopurine-allopurinol (LDTA) combination therapy is a commonly applied optimisation strategy in IBD patients with a skewed thiopurine metabolism. AIM: To assess continued LDTA maintenance treatment at annual intervals and explore risk factors for treatment cessation METHODS: Adult IBD patients treated with LDTA between 2009 and 2016 were retrospectively included. Data on the incidence of clinical and laboratory adverse events (AEs), including hepatotoxicity and myelotoxicity resulting in imposing LDTA therapy cessation and associated risk factors were collected. RESULTS: In total, 221 IBD patients (46% male, median age 42 years) were included. Maintenance LDTA treatment was continued in 78% of patients at 1 year (n = 145), 66% at 2 years (n = 83), 57% at 3 years (n = 52) and 52% at 4 years (n = 33). Treatment in patients receiving LDTA therapy for AEs during thiopurine monotherapy was more often continued than in patients initiating LDTA for other indications (eg, ineffectiveness of thiopurine monotherapy, routinely discovered skewed metabolism) (P = 0.016). Myelotoxicity during thiopurine monotherapy resolved in 87% and hepatotoxicity in 86% after median of 1.2 and 1.4 months after LDTA initiation. Cumulative incidence of AEs during LDTA resulting in therapy cessation within total follow-up of 449 treatment-years was 7% for clinical AEs, 4% for myelotoxicity and 1% for hepatotoxicity. CONCLUSION: LDTA therapy is a safe and beneficial optimisation strategy in IBD patients. Continued maintenance LDTA treatment is 52% after 4 years of treatment and most commonly affected by ineffectiveness of LDTA rather than LDTA-attributed toxicity. LDTA optimisation strategy is most advantageous in patients failing thiopurine monotherapy due to AEs.

6-methylmercaptopurine-induced leukocytopenia during thiopurine therapy in inflammatory bowel disease patients.

BACKGROUND AND AIM: Thiopurines have a favorable benefit-risk ratio in the treatment of inflammatory bowel disease. A feared adverse event of thiopurine therapy is myelotoxicity, mostly occurring due to toxic concentrations of the pharmacologically active metabolites 6-thioguaninenucleotides. In oncology, myelosuppression has also been associated with elevated 6-methylmercaptopurine (6-MMP). In this case series, we provide a detailed overview of 6-MMP-induced myelotoxicity in inflammatory bowel disease patients. METHODS: We retrospectively scrutinized pharmacological laboratory databases of five participating centers over a 5-year period. Patients with leukocytopenia at time of elevated 6-MMP levels (>5700 pmol/8 × 108 red blood cells) were included for detailed chart review. RESULTS: In this case series, we describe demographic, clinical, and pharmacological aspects of 24 cases of 6-MMP-induced myelotoxicity on weight-based thiopurine therapy with a median steady-state 6-MMP level of 14 500 pmol/8 × 108 red blood cells (range 6600-48 000). All patients developed leukocytopenia (white blood cell count 2.7 ± 0.9 × 109 /L) after a median period of 11 weeks after initiation of thiopurine therapy (interquartile range 6-46 weeks). Eighteen patients (75%) developed concurrent anemia (median hemoglobin concentration 6.9 × 109 /L), and four patients developed concurrent thrombocytopenia (median platelet count 104 × 109 /L). Leukocytopenia resolved in 20 patients (83%) within 4 weeks upon altered thiopurine treatment regimen, and white blood cell count was increasing, but not yet normalized, in the remaining four patients. CONCLUSION: We observed that thiopurine-induced myelotoxicity also occurs because of (extremely) high 6-MMP concentrations in patients with a skewed thiopurine metabolism. Continued treatment with adapted thiopurine therapy was successful in almost all patients.

Sex Is Associated with Adalimumab Side Effects and Drug Survival in Patients with Crohn's Disease.

BACKGROUND: Adalimumab (ADA) is an effective treatment for Crohn's disease (CD). In rheumatology, sex differences concerning the response to ADA therapy have been described. However, such differences have not yet been reported for patients with CD. As such, the aim of this study was to compare ADA treatment outcomes in male and female patients with CD. METHODS: A clinical cohort was formed of consecutive patients with CD starting ADA in a single tertiary center between March 2006 and February 2011. The cohort was followed up to August 2015. Clinical outcomes were primary nonresponse, secondary nonresponse, and drug survival (ongoing ADA use). Reasons for stopping ADA were recorded. Kaplan-Meier analysis and Cox regression were used to assess drug survival. RESULTS: The cohort consisted of 107 female and 81 male patients. Median follow-up was 6.0 years (range 0.3-9.2). Drug survival was higher in male than female patients (48.1% versus 30.8%, P = 0.016). Side effects were reported more often by female patients (81.3% versus 64.2%, P = 0.008), and female patients ceased ADA more often due to side effects (35.4% versus 18.4%, P = 0.017). In survival analysis, female sex was associated with higher cessation rates (P = 0.006). Cox regression also identified female sex (P = 0.020), along with higher baseline CD Activity Index (P = 0.003), as predictors of ADA cessation. CONCLUSIONS: Female sex is negatively associated with ADA drug survival. Female patients report more side effects and cease ADA because of side effects more often. A more personalized and sex-specific approach seems warranted to increase drug survival in female patients.

Routinely Established Skewed Thiopurine Metabolism Leads to a Strikingly High Rate of Early Therapeutic Failure in Patients With Inflammatory Bowel Disease.

BACKGROUND: The conventional thiopurines azathioprine and mercaptopurine are considered maintenance immunosuppressive drugs of choice in the treatment of inflammatory bowel disease (IBD). Unfortunately, treatment is often discontinued because of adverse events (AEs) or refractoriness, retrospectively associated with the high levels of the thiopurine metabolites 6-methylmercaptopurine ribonucleotides (6-MMPR). Patients with a clinically "skewed" thiopurine metabolism may be particularly at risk for therapy failure. We determined the predictive value of this pharmacological phenomenon in patients with IBD during regular thiopurine therapy. METHODS: Clinical effectiveness and tolerability of weight-based thiopurine therapy were determined in all patients with IBD displaying a skewed metabolism [ratio 6-MMPR/6-thioguanine nucleotide (6-TGN) >20]. All samples were routinely assessed between 2008 and 2012, as part of standard clinical follow-up after initiation of conventional thiopurine therapy. RESULTS: Forty-one (84%) of 49 included patients with IBD discontinued thiopurines (55% female, 53% with Crohn disease) with a median duration of 14 weeks (range, 7-155). The majority of patients with a skewed metabolism discontinued thiopurines because of adverse events (55%) or refractoriness (12%). The most commonly observed adverse event was hepatotoxicity (18 patients, 37%). Median 6-TGN level was 159 pmol/8 × 10 RBC (range, 46-419), median 6-MMPR level was 11,020 pmol/8 × 10 RBC (range, 3610-43,670), and the median 6-MMPR/6-TGN ratio was 72 (range, 29-367). Thiopurine therapy failure was associated with a ratio above 50 (P < 0.03). Hepatotoxicity occurred more frequently in patients with an extremely skewed metabolism (6-MMPR/6-TGN ratio >100) (P < 0.01). CONCLUSIONS: This study demonstrates that a routinely established skewed metabolism is a major risk factor for future thiopurine failure in patients with IBD. These observations imply that routine thiopurine metabolite measurements may be used as a prognostic tool to identify those patients with an aberrant-skewed metabolism at an early stage, possibly benefitting from therapy adjustments.