Application of a Precision-Dosing Model to a Real-World Cohort of Patients on Infliximab Maintenance Therapy: Drug Usage and Cost Analysis

Precision-dosing models forecast infliximab doses to achieve targeted trough concentrations in patients with inflammatory bowel disease (IBD). These models have shown to reduce nonresponse and improve patient outcomes. We compared infliximab doses determined by iDOSE precision dosing with standard dosing, and the associated drug costs, in patients with IBD. In this retrospective study, patients with IBD treated with infliximab every 8 weeks at 5 mg/kg were included. An infliximab dose was named dose X if 3 previous infliximab doses, laboratory values including trough infliximab concentrations, and the patient's weight were recorded. The actual dose X was compared to an iDOSE-predicted dose X. Net drug use and costs were evaluated. A total of 174 patients-56% men; median age, 36 (interquartile range, 29-47) years; 135 with Crohn disease; and 31 with ulcerative colitis-were included, with 417 dose X recordings. Median prior infliximab therapy was 2 (0-4) years. Comparing actual dose X with predicted dose X, 52% and 32% of doses were subtherapeutic when aiming for trough concentrations of 5-10 and 3-7 μg/mL, respectively. Treatment costs increased by 102% and 29% for the 2 trough ranges, respectively. On multivariate regression analysis, subtherapeutic infliximab concentrations were associated with ulcerative colitis compared with Crohn disease (odds ratio, 9.81; 95% confidence interval, 1.28-75.40; P = .028) and predose X infliximab trough concentration [odds ratio, 0.07; 95% confidence interval, 0.03-0.15; P < .001]. Over half of maintenance infliximab drug doses were too low to achieve infliximab blood concentrations of 5 μg/mL or greater. While applying precision dosing may improve patient outcomes, drug costs could be considerably greater.

Clinical utility of C-reactive protein-to-albumin ratio in the management of patients with inflammatory bowel disease

Background and Aim

C-reactive protein (CRP)-to-albumin ratio (CAR) is a novel score with prognostic value in inflammatory conditions. This study assessed the performance of CAR as an objective marker of disease activity and prediction of subtherapeutic infliximab trough levels in patients with inflammatory bowel disease (IBD).

Methods

A retrospective study was conducted on three different patient cohorts with IBD: patients who had (i) fecal calprotectin (FC) measurements; (ii) Mayo Endoscopic Scores; and (iii) infliximab trough levels available. The relative performances of CAR, albumin, and CRP were compared in predicting disease activity (based on FC or Mayo Endoscopic Score) and infliximab trough levels.

Results

In both the FC (n = 289) and endoscopy (n = 65) cohorts, albumin and CAR correlated with objective disease activity. CAR (area under the curve [AUC] 0.70) was only marginally better at detecting active disease, measured by FC, compared to CRP (AUC 0.68). A CAR >0.15 was able to detect Mayo 3 disease (AUC 0.83, sensitivity 81%, specificity 89%). Albumin (r = 0.38) and CAR (r = -0.42) correlated with infliximab trough levels (n = 204). The optimal CAR for detecting subtherapeutic infliximab trough levels was >0.08 (AUC 0.70, sensitivity 66%, specificity 64%). Both albumin and CAR were independent predictors of subtherapeutic infliximab trough levels but correlated poorly with infliximab trough levels longitudinally in the same patient.

Conclusion

CAR was only a modest discriminator of subtherapeutic infliximab levels and offers little more than CRP in detecting active disease. CAR has potential to detect severe Mayo 3 disease and could be calculated in patients admitted with suspected acute severe ulcerative colitis.

Intestinal barrier biomarkers in clinical evaluation of patients with inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is associated with chronic intestinal barrier dysfunction, though its non-invasive assessment remains challenging. This study aimed to determine how four putative circulating markers vary across differing states of intestinal inflammation and with therapy in patients with IBD.

METHODS

Plasma samples from one prospective cross-sectional and four longitudinal studies, including healthy controls, were analysed for markers of lipopolysaccharide translocation, lipopolysaccharide-binding protein (LBP) and soluble-CD14 (sCD14), and markers of epithelial injury, syndecan-1 and intestinal-type fatty acid-binding protein (IFABP). Inflammatory activity was determined using objective measures.

RESULTS

Compared with healthy subjects, concentrations of LBP and sCD14 were higher in patients with active (P < 0.001) and severe ulcerative colitis (UC) (P < 0.0001) and active Crohn's disease (CD) (P < 0.001). In UC in remission, LBP was less than in active disease (P = 0.011) LBP levels decreased longitudinally before and after induction of medical therapy in patients with IBD (P = 0.030) and as severe UC was brought into remission at weeks 2 and 12 (P ≤ 0.022). Response to treatment was associated with higher baseline levels of LBP (P = 0.019) and soluble-CD14 (P = 0.014). Concentrations of syndecan-1 and IFABP were or tended to be lower in UC and CD in active disease and did not change with successful therapy.

CONCLUSION

While markers of epithelial injury were subnormal with active disease and did not change with therapy, markers of lipopolysaccharide translocation directly reflected intestinal inflammation, reduced with successful therapy and predicted treatment response.

Clinical trial: Combination allopurinol-thiopurine versus standard thiopurine in patients with IBD escalating to immunomodulators (the DECIDER study)

BACKGROUND

Thiopurines are established treatments for inflammatory bowel disease (IBD), yet concerns remain regarding their safety.

AIM

To evaluate the use of thiopurine-allopurinol combination therapy compared to standard thiopurine therapy in IBD.

METHODS

We performed a multicentre, randomised, placebo-controlled trial to compare the efficacy and safety of thiopurine-allopurinol versus thiopurine with placebo for adults commencing a thiopurine for IBD. Patients had active disease at baseline; dosing of therapy was based on a pre-specified regimen and subsequent metabolites. The primary outcome was the proportion of patients achieving a composite of symptomatic disease activity remission (Harvey Bradshaw Index <5 for Crohn's disease, Simple Clinical Colitis Activity Index <4 for ulcerative colitis) and a faecal calprotectin <150 μg/g after 26 weeks of treatment.

RESULTS

The trial was terminated early due to slow recruitment. We randomised 102 participants (54 thiopurine-allopurinol, 48 thiopurine with placebo) with similar age (median 42 vs 48 years) and sex distribution (46% women per group). A higher proportion achieved the primary outcome in the thiopurine-allopurinol group (50% vs 35%, p = 0.14) and fewer participants stopped their allocated therapy due to adverse events (11% vs 29%, p = 0.02). Also, within the thiopurine-allopurinol group, thiopurine dose adjustments were less frequent (69% vs 92%, p = 0.03), a higher proportion achieved an early therapeutic 6-TGN level at week 6 (71% vs 53%, p = 0.19), and adverse events attributed to therapy were less frequent (15% vs 44%, p = 0.002).

CONCLUSION

Thiopurine-allopurinol therapy is safe and mitigates thiopurine adverse effects, thus enhancing tolerability without compromising efficacy (ACTRN12613001347752).

Infections in inflammatory bowel disease patients on immunomodulator and biologic therapy are not associated with high serum drug levels

BACKGROUND

Inflammatory bowel disease (IBD) therapies now utilise higher doses of immunomodulatory and biologic therapies, predisposing patients to an increased risk of infections.

AIMS

We aimed to determine whether infections were associated with high anti-tumour necrosis factor (TNF) drug levels in IBD and to quantify the risk and consequences of infections.

METHODS

Two retrospective studies were performed, a descriptive cohort study and a matched case-control study. For the matched case-control study, cases of infection occurring on anti-TNF agents were matched in a 1:2 ratio to controls of anti-TNF treated patients without infections.

RESULTS

In the descriptive study, 76 infections occurred in 60 patients, including 49 bacterial, 24 viral, four fungal and four parasitic. Of these, 61 (80.3%) were on biologics, 49 (64.5%) on immunomodulators and 11 (14.5%) on corticosteroids. Thirty-four (44.7%) were on combination therapy, 27 (35.5%) on biologic monotherapy and 15 (19.7%) on immunomodulator monotherapy. Median anti-TNF drug levels in infection cases were 3.9 μg/mL for infliximab and 6.0 μg/mL for adalimumab. In the case-control study, 32 cases of infection in 27 anti-TNF treated patients were matched with 64 anti-TNF treated controls without infections. Among infection cases, 59.5% were on combination therapy versus 40.6% on biologic monotherapy (P = 0.59). Median drug levels for cases and controls respectively were 3.9 μg/mL versus 5.5 μg/mL for infliximab (P = 0.72) and 6.0 μg/mL versus 9.9 μg/mL for adalimumab (P = 0.34).

CONCLUSION

Infections in patients with IBD were common, and the risk was highest with combination therapy. Infections were not associated with high serum anti-TNF levels.

A novel Monash Pouch diet in patients with an ileoanal pouch is tolerable and has favorable metabolic luminal effects

Aims

To evaluate a whole-food diet strategy (the Monash Pouch diet [MPD]) designed based on the interacting roles dietary factors play with pouch health. Specifically, its tolerability and acceptability, whether it achieved its dietary and metabolic goals, and the effects on symptoms and inflammation were examined.

Methods

In a 6-week open-label trial, patients with ileoanal pouches educated on the MPD were assessed regarding diet tolerability and acceptance, food intake (7-day food diaries), pouch-related symptoms (clinical pouchitis disease activity index), and, in 24-h fecal samples, calprotectin, fermentative biomarkers, and volatile organic compounds (VOC).

Results

Of 12 patients, 6 male, mean (SD) age 55 (5) and pouch age 13 (2) years, one withdrew with partial small bowel obstruction. Tolerability was excellent in 9 (75%) and acceptance was high (81%). Targeted changes in dietary intake were achieved. Fecal branched- to short-chain fatty acid ratio increased by median 60 [IQR: 11-80]% (P = 0.02). Fecal VOCs for 3 compounds were also increased, 2-methyl-5-propan-2-ylcyclohexa-1,3-diene (Fold-change [FC] 2.08), 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane (FC 3.86), propan-2-ol (FC 2.10). All six symptomatic patients achieved symptomatic remission (P = 0.03). Fecal calprotectin at baseline was 292 [176-527] μg/g and at week 5 was 205 [148-310] μg/g (P = 0.72).

Conclusion

Well tolerated and accepted, the MPD achieved targeted changes in intakes and fermentation of carbohydrates relative to that of protein. There were signals of improvement in symptoms. These results indicate the need for a randomized-controlled trial. (Trial registration: ACTRN12621000374864; https://www.anzctr.org.au/ACTRN12621000374864.aspx).

Adalimumab Drug Levels at Secondary Loss of Response Do Not Predict Response to Dose-intensification in Crohn's Disease: A Retrospective, International Multicenter Study

BACKGROUND

The exposure-response relationship is less established for adalimumab (ADA) compared with infliximab in inflammatory bowel disease (IBD). Evidence supporting therapeutic drug monitoring post dose-intensification of ADA is limited. We aimed to explore the association between ADA drug levels and Crohn's disease (CD) activity at loss of response, and at 6 and 12 months post dose-intensification.

METHODS

We performed a retrospective study of adult patients with CD receiving dose-intensified weekly ADA following secondary loss of response at 3 tertiary centers across 5 years. ADA trough levels were analyzed using a drug-sensitive enzyme-linked immunosorbent assay at loss of response, and 6 and 12 months after dose-intensification. Rates of clinical remission, objective remission (C-reactive protein <5 mg/L, fecal calprotectin <150 µg/g, or absence of inflammation at endoscopy or imaging), and ADA failure were investigated.

RESULTS

A total of 131 CD patients were included, with a median disease duration of 9 (interquartile range, 4-17) years. 51% were biologic exposed prior to ADA and 50% received concomitant immunomodulators. Baseline drug levels measured at secondary loss of response did not discriminate between subsequent responders and non-responders at either 6 or 12 months post dose-intensification. However, both higher drug levels at 6 and 12 months and a higher increment from baseline were associated with improved outcomes. On receiver-operating characteristic analyses, post-escalation ADA drug levels >10.7 µg/mL (area under the receiver-operating characteristic curve [AUROC], 0.66; P = .013) and >10.9 µg/mL (AUROC, 0.67; P = .032) were associated with objective remission at 6 and 12 months, respectively.

CONCLUSIONS

Drug levels following dose-intensification rather than at the time of secondary loss of response were associated with subsequent CD remission.

Perceived dietary intolerances, habitual intake and diet quality of patients with an ileoanal pouch: Associations with pouch phenotype (and behaviour)

BACKGROUND AND AIMS

Ileoanal pouch patients frequently attribute pouch-related symptoms and pouchitis with diet. We aimed to assess perceived food intolerance and habitual dietary intake and their relationship with pouch indication, symptoms and current or history of pouchitis.

METHODS

In this cross-sectional study, patients with an ileoanal pouch completed a dietary intolerance and a food frequency questionnaire, that specifically quantifies habitual intake of FODMAPs. Perceived dietary intolerance rates, nutrient intake and diet quality, and their differences based on pouch indication, symptom, and current or history of pouchitis were assessed. Associations between intolerances and intake, and between dietary intake with pouchitis risk were analysed using univariable and multivariable regression analysis.

RESULTS

Of the 58 (10 FAP and 48 UC) patients with complete data, 81% of UC and 80% of FAP patients reported dietary intolerances. Overall diet quality was good. Differences in dietary intake were limited to a few food groups. Patients with a history of pouchitis had a lower intake of fruits (p = 0.03) and nuts (p = 0.004). Patients with current pouchitis had a lower intake of nuts (p = 0.02). On multivariable logistic regression, intake of dietary fibre was associated negatively [OR 0.68(95%CI:0.51-0.92)] and of non-digestible oligosaccharides positively with pouchitis history [OR 5.5(95% CI:1.04-29.1)].

CONCLUSIONS

In patients with an ileoanal pouch, perceived dietary intolerances are common but had minimal impact on nutritional adequacy and diet quality. Negative associations of the intakes of fruits, nuts and dietary fibre and positive association with non-digestible oligosaccharides with a history of pouchitis require further study to inform dietary recommendations.

The Role of Low-Dose Oral Methotrexate in Increasing Anti-TNF Drug Levels and Reducing Immunogenicity in IBD

Concomitant immunomodulation is utilised in combination with anti-TNF therapy for IBD primarily to increase drug levels and prevent anti-drug antibody formation. Whilst thiopurines have traditionally been the immunomodulator of choice in IBD populations, there are concerns regarding the long-term safety of the prolonged use of these agents: particularly an association with lymphoproliferative disorders. Given this, we have explored the existing literature on the use of low-dose oral methotrexate as an alternative immunomodulator for this indication. Although there is a lack of data directly comparing the efficacies of methotrexate and thiopurines as concomitant immunomodulators, the available literature supports the use of methotrexate in improving the pharmacokinetics of anti-TNF agents. Furthermore, low-dose oral methotrexate regimens appear to have comparable efficacies to higher-dose parenteral administration and are better tolerated. We suggest that clinicians should consider the use of low-dose oral methotrexate as an alternative to thiopurines when the primary purpose of concomitant immunomodulation is to improve anti-TNF pharmacokinetics.

An Extremes of Phenotype Approach Confirms Significant Genetic Heterogeneity in Patients with Ulcerative Colitis

BACKGROUND AND AIMS

Ulcerative colitis [UC] is a major form of inflammatory bowel disease globally. Phenotypic heterogeneity is defined by several variables including age of onset and disease extent. The genetics of disease severity remains poorly understood. To further investigate this, we performed a genome wide association [GWA] study using an extremes of phenotype strategy.

METHODS

We conducted GWA analyses in 311 patients with medically refractory UC [MRUC], 287 with non-medically refractory UC [non-MRUC] and 583 controls. Odds ratios [ORs] were calculated for known risk variants comparing MRUC and non-MRUC, and controls.

RESULTS

MRUC-control analysis had the greatest yield of genome-wide significant single nucleotide polymorphisms [SNPs] [2018], including lead SNP = rs111838972 [OR = 1.82, p = 6.28 × 10-9] near MMEL1 and a locus in the human leukocyte antigen [HLA] region [lead SNP = rs144717024, OR = 12.23, p = 1.7 × 10-19]. ORs for the lead SNPs were significantly higher in MRUC compared to non-MRUC [p < 9.0 × 10-6]. No SNPs reached significance in the non-MRUC-control analysis (top SNP, rs7680780 [OR 2.70, p = 5.56 × 10-8). We replicate findings for rs4151651 in the Complement Factor B [CFB] gene and demonstrate significant changes in CFB gene expression in active UC. Detailed HLA analyses support the strong associations with MHC II genes, particularly HLA-DQA1, HLA-DQB1 and HLA-DRB1 in MRUC.

CONCLUSIONS

Our MRUC subgroup replicates multiple known UC risk variants in contrast to non-MRUC and demonstrates significant differences in effect sizes compared to those published. Non-MRUC cases demonstrate lower ORs similar to those published. Additional risk and prognostic loci may be identified by targeted recruitment of individuals with severe disease.

Higher Anti-tumor Necrosis Factor-α Levels Correlate With Improved Radiologic Outcomes in Crohn's Perianal Fistulas

BACKGROUND & AIMS

Higher anti-tumor necrosis factor-α (TNF) drug levels are associated with improved clinical healing of Crohn's perianal fistulas. It is unclear whether this leads to improved healing on radiologic assessment. We aimed to evaluate the association between anti-TNF drug levels and radiologic outcomes in perianal fistulising Crohn's disease.

METHODS

A cross-sectional retrospective multicenter study was undertaken. Patients with perianal fistulising Crohn's disease on maintenance infliximab or adalimumab, with drug levels within 6 months of perianal magnetic resonance imaging were included. Patients receiving dose changes or fistula surgery between drug level and imaging were excluded. Radiologic disease activity was scored using the Van Assche Index, with an inflammatory subscore calculated using indices: T2-weighted imaging hyperintensity, collections >3 mm diameter, rectal wall involvement. Primary endpoint was radiologic healing (inflammatory subscore ≤6). Secondary endpoint was radiologic remission (inflammatory subscore = 0).

RESULTS

Of 193 patients (infliximab, n = 117; adalimumab, n = 76), patients with radiologic healing had higher median drug levels compared with those with active disease (infliximab 6.0 vs 3.9 μg/mL; adalimumab 9.1 vs 6.2 μg/mL; both P < .05). Patients with radiologic remission also had higher median drug levels compared with those with active disease (infliximab 7.4 vs 3.9 μg/mL; P < .05; adalimumab 9.8 vs 6.2 μg/mL; P = .07). There was a significant incremental reduction in median inflammatory subscores with higher anti-TNF drug level tertiles.

CONCLUSIONS

Higher anti-TNF drug levels were associated with improved radiologic outcomes on magnetic resonance imaging in perianal fistulising Crohn's disease, with an incremental improvement at higher drug level tertiles for both infliximab and adalimumab.

Editorial: is it not just PROs, but the most important individual PRO, that really matters in Crohn's disease?

This article is linked to Wong et al papers. To view these articles, visit https://doi.org/10.1111/apt.16805 and https://doi.org/10.1111/apt.16866

Ustekinumab levels in pregnant women with inflammatory bowel disease and infants exposed in utero

BACKGROUND

Ustekinumab is increasingly used in pregnant women with inflammatory bowel disease (IBD). Existing safety data are reassuring, but the stability of ustekinumab levels in pregnancy, degree of transfer to the infant and time to infant clearance are unknown.

METHODS

In this prospective observational study, ustekinumab-exposed women with IBD had trough levels measured in each trimester of pregnancy and at delivery. Infant ustekinumab levels were measured at delivery and ongoing until clearance was achieved. Trough ustekinumab level stability in individuals across pregnancy was compared by Skillings-Mack test. Spearman coefficients were used to correlate maternal and infant delivery levels, and median time to infant ustekinumab clearance was defined.

RESULTS

19 pregnant women receiving ustekinumab were included. There was no difference in ustekinumab levels across pregnancy in those with two or more representative trough levels (P = 0.83, n = 11). Infant delivery ustekinumab levels were higher than maternal levels, with a median infant:maternal ratio of 1.79 (IQR 1.26-3.1). There was a positive correlation between maternal and infant delivery ustekinumab levels (r = 0.75, P = 0.001) and an inverse correlation between the number of days from final antenatal dose and delivery infant ustekinumab level (r = -0.65, P = 0.006). Median time of infant ustekinumab clearance was 9 (range 6-19) weeks (n = 9).

CONCLUSION

Ustekinumab drug levels appear stable in pregnancy, with a delivery infant:maternal ratio similar to that of anti-TNFs. Infant ustekinumab clearance was complete by 20 weeks post-partum, however, infants exposed in utero should avoid live vaccination before 12 months of age until further clearance data are obtained.

Accuracy of Gastrointestinal Ultrasound and Calprotectin in the Assessment of Inflammation and its Location in Patients with an Ileoanal Pouch

BACKGROUND AND AIMS

In symptomatic patients with ileoanal pouches, pouchoscopy is needed for accurate diagnosis but is invasive. We aimed to assess the utility of non-invasive gastrointestinal ultrasound and faecal calprotectin in ileoanal pouch patients.

METHODS

Patients with an ileoanal pouch were consecutively enrolled in this cross-sectional study from clinics in Victoria, Australia. The pouchitis disease activity index was used as a reference standard. Video-recorded pouchoscopies were reviewed by three gastroenterologists. Pouch, pre-pouch, and cuff biopsies were reviewed by a single pathologist. Ultrasound was performed by a single gastroenterologist transabdominally and transperineally. Faecal calprotectin was measured from morning stool samples. All examiners were blinded to patients' clinical history.

RESULTS

A total of 44 participants had a pouchoscopy, of whom 43 had a faecal calprotectin test and 42 had an ultrasound; 17 had pouchitis, 15 had pre-pouch ileitis, and 16 had cuffitis. Pouch wall thickness of <3 mm was 88% sensitive in excluding pouchitis, and pouch wall thickness of ≥4 mm was 87% specific in diagnosing pouchitis. Transabdominal ultrasound had good utility [area under the curve: 0.78] in diagnosing moderate-severe pre-pouch ileitis. Transperineal ultrasound had good utility for the diagnosis of pouchitis [area under the curve: 0.79]. Faecal calprotectin differentiated inflammatory from non-inflammatory pouch disorders, such as irritable pouch syndrome, with an area under the curve of 0.90. Faecal calprotectin <100 µg/g ruled out inflammatory pouch disorders with a sensitivity of 94%.

CONCLUSIONS

Faecal calprotectin and ultrasound are accurate and complementary tests to diagnose and localise inflammation of the ileoanal pouch. Prospective studies are needed to validate proposed sonographic indices and calprotectin levels.

The Reliability and Accuracy of Endoscopic Items and Scores Used in the Assessment of the Ileoanal Pouch and Cuff

BACKGROUND AND AIMS

Currently used endoscopic items for the assessment of pouchitis and cuffitis have deficiencies in reliability and validation. We assessed the reliability and accuracy of new endoscopic items for pouchitis and of the Ulcerative Colitis Endoscopic Index of Severity [UCEIS] for cuffitis.

METHODS

Three new endoscopic items were assessed and included in the Monash pouchitis endoscopic subscore: bleeding [absent/contact/spontaneous]; erosions [absent/<10/≥10]; and ulceration [absent/<10%/≥10%]. Three raters evaluated 44 pouchoscopy videos in duplicates, in random order. Intra- and inter-rater reliability of all endoscopic items and UCEIS were assessed. Clinical and histological pouchitis disease activity index [PDAI] subscores were also assessed and faecal calprotectin was measured.

RESULTS

All three Monash endoscopic items had substantial intra-rater reliability with intraclass correlation coefficients [ICCs] >0.61 [95% CI >0.61], compared with only ulcers from the currently used PDAI endoscopic subscore, but inter-rater reliability was only substantial for ulceration and no better than those of the currently used endoscopic items. The Monash endoscopic subscore had a strong positive correlation with the reference standard global endoscopic lesion severity r = 0.80 [95% CI 0.80-0.80] and the reference standard PDAI endoscopic subscore r = 0.70 [95% CI 0.67-0.73], which was higher than the correlation observed for the currently used PDAI endoscopic subscore. The UCEIS had substantial intra-rater reliability, but only fair inter-rater reliability and poor diagnostic performance for cuffitis.

CONCLUSIONS

The Monash endoscopic items, and endoscopic subscore they generate, have enhanced overall performance compared with the currently used PDAI items and subscore. Further validation and responsiveness to change in disease state are indicated.

De-escalation from Dose-Intensified Anti-TNF Therapy Is Successful in the Majority of IBD Patients at 12 Months

BACKGROUND

Data on outcomes following de-escalation of intensified anti-TNF therapy in inflammatory bowel disease (IBD) are limited and concerns about relapse limit willingness to de-escalate.

AIMS

To evaluate rates of successful de-escalation at 12 months and to determine factors that may predict success.

METHODS

Single-centre experience of IBD patients that were de-escalated following deep remission on dose-intensified infliximab (IFX) or adalimumab (ADA) for secondary loss of response. Patients were classified as 'successes' if remaining on reduced anti-TNF or 'failures' if requiring re-escalation, steroids, surgery or enrolment into a clinical trial at 12 months. Patient demographics, disease characteristics, biomarkers (faecal calprotectin, C-reactive protein, albumin) and anti-TNF drug levels were collected 6-monthly.

RESULTS

Of 25 patients (20 CD, 5 UC), 16 (64%) were successes 12 months post-de-escalation. Median time to failure was 6 months. Six of the nine failures required anti-TNF re-escalation and three entered a clinical trial. Re-escalation recaptured response in all six patients. There was no significant difference in baseline biomarker activity between the two groups. There was no difference in infliximab levels between successes and failures at the time of de-escalation (5.5 vs. 5.3, p = 0.63) as well as 6 months (3.1 vs. 4.6, p = 0.95) and 12 months (3.2 vs. 4.5, p = 0.58) post-de-escalation.

CONCLUSION

Nearly two-thirds of patients remained on reduced anti-TNF dosing 12 months after de-escalation. All patients who failed de-escalation were recaptured after dose re-escalation. De-escalation with close monitoring may be considered in patients on intensified anti-TNF therapy in sustained remission.

A Single Educational Intervention Improves Pregnancy-Related Knowledge and Emotional Health Among Women With IBD Who Are Pregnant or Wish to Conceive

BACKGROUND

There is considerable interest in improving the education and care of women with inflammatory bowel disease (IBD) to improve pregnancy outcomes. Despite increased awareness, not all women with IBD have access to pregnancy-related education and the quality of counseling is variable. We aimed to assess the effectiveness of a simple educational intervention for improving pregnancy-related knowledge and to evaluate the effect of education on patient outcomes including anxiety, depression, and quality of life in women with IBD.

METHODS

This prospective study of women with IBD who were pregnant or planning a pregnancy evaluated the effectiveness of a single gastroenterologist-led educational intervention in improving pregnancy-related knowledge, measured using the Crohn's and Colitis Pregnancy Knowledge score 1 month postintervention. Secondary outcomes included the effect on anxiety and depression, quality of life, medication adherence, and patient satisfaction.

RESULTS

One hundred women with IBD were recruited. Fifty percent were pregnant at the time of the intervention. Baseline knowledge scores were similar independent of the patients' pregnancy status or whether they had previously received counseling from their gastroenterologist. Median Crohn's and Colitis Pregnancy Knowledge scores postintervention (n = 82) were higher than preintervention scores (14/17 vs 10/17; P < 0.001). In addition, 32% of patients had poor knowledge at baseline (score ≤7/17), compared to only 5% after the intervention (P < 0.001). There was a significant improvement in total anxiety and depression and quality of life scores postintervention. Medication adherence and patient satisfaction were excellent.

CONCLUSIONS

Uptake of this gastroenterologist-led educational intervention has the potential to improve pregnancy knowledge, promote medication adherence, and enhance quality of life for women with IBD globally.

Evolving Role of Thiopurines in Inflammatory Bowel Disease in the Era of Biologics and New Small Molecules

In recent years, with the increasing availability of biologic therapies and due to safety concerns, the role of thiopurines in the management of inflammatory bowel disease has been questioned. While acknowledging that the benefit/risk ratio of biologic therapies is very high, they are expensive and are not required by a majority of patients. Therefore, thiopurines do retain an important role as steroid-sparing and maintenance agents when used as monotherapy, and in combination therapy with biologics due to their clinical and pharmacokinetic optimization of anti-tumor necrosis factor agents in particular. Safety concerns with thiopurines are real but also relatively rare, and with careful pre-treatment screening and ongoing monitoring thiopurine benefits outweigh risks in the majority of appropriately selected patients. Measurement of newer pharmacogenomic markers such as nudix hydrolase 15 (NUDT15), when combined with knowledge of existing known mutations (e.g., thiopurine S-methyltransferase-TPMT), will hopefully minimize the risk of potentially life-threatening leukopenia by allowing for pre-treatment dosing stratification. Further optimization of thiopurine dosing via measurement of thiopurine metabolites should be performed routinely and is superior to weight-based dosing. The association of thiopurines with malignancies including lymphoproliferative disorders needs to be recognized in all patients and individualized in each patient. The decrease in lymphoma risk after thiopurine cessation provides an incentive for thiopurine de-escalation in appropriate patients after a period of prolonged deep remission. This review will summarize the current role of thiopurines in inflammatory bowel disease management and provide recommendations for commencing and monitoring therapy, and when to consider de-escalation.

E-Health and remote management of patients with inflammatory bowel disease: lessons from Denmark in a time of need

In Denmark, remote monitoring and management of inflammatory bowel disease (IBD) started two decades ago with the web application Constant Care. The disease monitoring in Constant Care consists of simple disease activity questionnaires and home measurement of faecal calprotectin, a stool biomarker for inflammation. It has now been implemented in clinical practice at North Zealand University Hospital in Denmark. Digital health care solutions facilitate remote contact between patients and healthcare providers and have been shown to reduce time to remission, outpatient visits and hospital admissions, and increase adherence to medical therapy, quality of life and disease and treatment knowledge. In Australia, E-Health is an area of increasing interest, particularly given the significant distances travelled by rural patients to access specialist care. There are several foreseeable benefits to incorporating E-Health/remote monitoring into Australian IBD management, including reduced burdens of time and cost on rural patients, and more efficient management of well outpatients, thereby increasing clinic availability for acutely unwell patients. The significant portion of IBD patients managed in private practice in Australia, and the infrastructure within private practice that is well suited to implementation of E-Health makes Australia a viable setting for an E-Health IBD management model like Denmark's Constant Care model. One pilot study is currently underway investigating the feasibility of rapid and remote IBD monitoring and E-Health in an Australian IBD population. The current COVID-19 pandemic has further illustrated the importance of telehealth as a means of maintaining health services to patients in geographic, or social, isolation.

Development of a Simple, Serum Biomarker-based Model Predictive of the Need for Early Biologic Therapy in Crohn's Disease

BACKGROUND

Early or first-line treatment with biologics, as opposed to conventional immunomodulators, is not always necessary to achieve remission in Crohn's disease [CD] and may not be cost-effective. This study aimed to develop a simple model to predict the need for early biologic therapy, in order to risk-stratify CD patients and guide initial treatment selection.

METHODS

A model-building study using supervised statistical learning methods was conducted using a retrospective cohort across two tertiary centres. All biologic-naïve CD patients who commenced an immunomodulator between January 1, 2004 and December 31, 2016, were included. A predictive score was derived using Cox regression modelling of immunomodulator failure, and was internally validated using bootstrap resampling.

RESULTS

Of 410 patients [median age 37 years, 47% male, median disease duration 4.7 years], 229 [56%] experienced immunomodulator failure [39 required surgery, 24 experienced a new stricture, 44 experienced a new fistula/abscess, 122 required biologic escalation] with a median time to failure of 16 months. Independent predictors of treatment failure included raised C-reactive protein [CRP], low albumin, complex disease behaviour, younger age, and baseline steroids. Highest CRP and lowest albumin measured within the 3 months preceding immunomodulator initiation outperformed baseline measurements. After model selection, only highest CRP and lowest albumin remained and the resultant Crohn's Immunomodulator CRP-Albumin [CICA] index demonstrated robust optimism-corrected discriminative performance at 12, 24, and 36 months (area under the curve [AUC] 0.84, 0.83, 0.81, respectively).

CONCLUSIONS

The derived CICA index based on simple, widely available markers is feasible, internally valid, and has a high utility in predicting immunomodulator failure. This requires external, prospective validation.

Thiopurines and their optimization during infliximab induction and maintenance: A retrospective study in Crohn's disease

BACKGROUND AND AIM

Combining therapy with a thiopurine is favored when commencing infliximab in Crohn's disease; however, the optimal 6-thioguanine nucleotide (TGN) level and how long to continue thiopurines after induction are uncertain. We aimed to compare outcomes after induction and during maintenance in combination therapy versus infliximab monotherapy in Crohn's and to examine whether TGN levels were associated with outcomes.

METHODS

Crohn's patients induced with infliximab with or without concomitant thiopurines were retrospectively identified. Response to induction and clinical outcomes in subsequent 6-month maintenance semesters were analyzed. A TGN level ≥235 pmol/8 × 10⁸ red blood cells was considered therapeutic.

RESULTS

In 89 patients, response to induction was higher in combination therapy than monotherapy (74 vs 47%, P = 0.04). This benefit was only seen in patients with a therapeutic TGN (odds ratio 3.72, confidence interval 1.07-13.0, P = 0.04). Combination therapy during induction yielded a three times longer time to subsequent need for treatment escalation or treatment failure compared with monotherapy (29 vs 9 months, P = 0.01), with both therapeutic and subtherapeutic TGNs independent predictors on multivariate analysis. Among 370 semesters, there was no difference in outcomes between combination therapy and monotherapy (P = 0.42), nor when combination semesters were stratified by therapeutic versus subtherapeutic TGN (P = 0.56). In semester 1 only, a significantly higher remission rate was observed with therapeutic compared with subtherapeutic TGN (76% vs 33%, P = 0.02).

CONCLUSIONS

Combination therapy dosed with an optimized thiopurine was superior to infliximab monotherapy for induction of response, durability of response, and clinical outcomes in the first 6 months following induction. Thereafter, combination therapy yielded no clinical advantage, supporting consideration of thiopurine withdrawal on a case-by-case basis.

Maternal thiopurine metabolism during pregnancy in inflammatory bowel disease and clearance of thiopurine metabolites and outcomes in exposed neonates

BACKGROUND

Azathioprine and mercaptopurine are considered safe during pregnancy. However, the pharmacokinetic effects of pregnancy on thiopurine metabolism are undefined.

AIMS

To characterise thiopurine metabolism in pregnancy and measure infant metabolite levels and outcomes.

METHODS

Women with IBD who were taking a thiopurine and pregnant or trying to conceive were recruited. Maternal thiopurine metabolites were measured pre-conception, in each trimester, at delivery and post-partum. Infant metabolite levels, full blood examination and liver function testing were performed at birth, and repeated until levels undetectable and haematological and biochemical abnormalities resolved.

RESULTS

Forty patients were included with measurements on at least two occasions, and two with only mother-baby levels at delivery. The median maternal 6-TGN level dropped in the second trimester compared with post-partum (179.0 vs 323.5 pmol/8 × 10⁸ RBCs, P < 0.001) and the median 6-MMP level increased in the second trimester compared with post-partum (1103.0 vs 329.5 pmol/8 × 10⁸ RBCs, P < 0.01). At delivery, the median 6-TGN level was lower in infants (n = 20) than mothers (78.5 vs 217 pmol/8 × 10⁸ RBCs) (P < 0.001). Metabolites were not detected at 6 weeks in any infants. Anaemia was not seen, but thrombocytosis and abnormal liver biochemistry were detected in 80% of infants from 6 weeks, which gradually improved.

CONCLUSIONS

6-TGN levels decrease and 6-MMP levels increase in the second trimester of pregnancy. Infants are exposed to thiopurine metabolites at low levels with clearance by 6 weeks and no anaemia. The cause of infant thrombocytosis and abnormal liver biochemistry in the absence of metabolites is unclear.

Long-term Safety and Efficacy of the Anti-MAdCAM-1 Monoclonal Antibody Ontamalimab [SHP647] for the Treatment of Ulcerative Colitis: The Open-label Study TURANDOT II

BACKGROUND AND AIMS

Ontamalimab, a fully-human monoclonal antibody targeting MAdCAM-1, induced remission in patients with moderate-to-severe ulcerative colitis [UC] in the TURANDOT study. We aimed to assess long-term safety, tolerability, and efficacy of ontamalimab in TURANDOT II.

METHODS

TURANDOT II was a phase 2, multicentre, open-label [OL] study in patients with moderate-to-severe UC who completed TURANDOT on placebo or ontamalimab (NCT01771809). Patients were randomised to 75 mg or 225 mg ontamalimab every 4 weeks for 72 weeks [OL1]. The dosage could be increased to 225 mg from Week 8 at the investigator's discretion. All patients then received 75 mg every 4 weeks for 72 weeks [OL2], followed by 6-month safety follow-up. The primary objective was safety, measured by adverse events [AEs], serious AEs [SAEs], and AEs leading to withdrawal. Mucosal healing [MH; centrally read endoscopy] was assessed.

RESULTS

Of 330 patients, 180 completed OL1; 94 escalated to 225 mg; 127 completed OL2. Overall, 36.1% experienced drug-related AEs. The most common SAE [10.0%] was worsening/ongoing UC; 5.5% of patients had serious infections, the most common being gastroenteritis [0.9%]. One death and four cancers [all unrelated to ontamalimab] occurred. No PML [progressive multifocal leukoencephalopathy]/lymphoproliferative disorders occurred. Geometric mean high-sensitivity C-reactive protein [hsCRP] and faecal calprotectin decreased across OL1 in both dose groups. The proportion of patients assigned to placebo in TURANDOT achieving MH increased from 8.8% [6/68] at baseline to 35.3% at Week 16 [24/68; non-responder imputation]. The corresponding increase in the ontamalimab group was from 23.3% [61/262] to 26.7% [70/262].

CONCLUSIONS

Ontamalimab was well tolerated up to 144 weeks in patients with moderate-to-severe UC, with good safety and efficacy.

Infliximab, adalimumab and vedolizumab concentrations across pregnancy and vedolizumab concentrations in infants following intrauterine exposure

BACKGROUND

The impact of pregnancy on levels of biologic agents in patients with IBD is undefined and time to elimination in vedolizumab-exposed infants is unknown.

AIMS

To determine the effect of pregnancy on infliximab, adalimumab and vedolizumab levels and to study infant vedolizumab clearance METHODS: In a prospective observational study, maternal drug levels were measured pre-conception, in each trimester, at delivery and postpartum. The association between drug levels and gestation in weeks was assessed using generalised estimating equation modelling. Infant vedolizumab levels were performed at birth (cord blood), 6 weeks and 3 months or until undetectable.

RESULTS

We included 50 IBD patients (23 on infliximab, 15 on adalimumab and 12 on vedolizumab) with at least two intrapartum observations, plus 5 patients on vedolizumab with only mother and baby samples at delivery. Modelling showed no change in adalimumab levels, an increase in infliximab levels of 0.16 (95% CI 0.08-0.24) µg/L/week (P < 0.001) and a decrease of 0.18 (95% CI: -0.33 to -0.02) µg/L/week (P = 0.03) for vedolizumab. In 17 mother-baby pairs, median infant vedolizumab levels at birth were lower than maternal levels (P < 0.05) with an infant:maternal ratio of 0.7 (IQR 0.5-0.9). Vedolizumab was undetectable between 15 and 16 weeks of age in all 12 infants completing follow-up testing.

CONCLUSIONS

During pregnancy, adalimumab levels remain stable, while infliximab levels increase and vedolizumab levels decrease. However, the increments were small suggesting that intrapartum therapeutic drug monitoring and dose adjustment are not indicated. Unlike infliximab and adalimumab, infant vedolizumab levels are lower in cord blood than in mothers and appear to clear rapidly.

Review article: the impact of diet on ileoanal pouch function and on the pathogenesis of pouchitis

BACKGROUND

There is expanding interest in the role that diet plays in ileoanal pouch function and in the pathogenesis of pouchitis.

AIMS

To present a narrative review of published literature regarding the relationship of diet with pouch function and the pathogenesis of pouchitis, and to provide potentially beneficial dietary strategies.

METHODS

Current relevant literature was summarised and critically examined.

RESULTS

Dietary components influence pouch function via their effect on upper gastrointestinal transit, small bowel water content and the structure and fermentative activity of the pouch microbiota. FODMAPs in fruits and vegetables appear to affect pouch function the most, with intake positively associated with increased stool frequency and reduced consistency. Dietary factors that influence the pathogenesis of pouchitis appear different and, at times, opposite to those better for optimising function. For example, risk of pouchitis appears to be inversely associated with intake of fruits. The food components mechanistically responsible for this observation are not known, but a rich supply of fermentable fibres and micronutrients in such foods might play a beneficial role via modulation of microbial community structure (such as increasing diversity and/or changing microbial communities to favour 'protective' over 'pathogenic' bacteria) and function and/or anti-inflammatory effects.

CONCLUSION

Available data are weak but suggest tailoring dietary recommendations according to pouch phenotype/behaviour and pouchitis risk might improve outcomes. More sophisticated dietary strategies that utilise the physiological and pathophysiological effects of dietary components on ileoanal pouches have potential to further improve outcomes. Well designed, adequately powered studies are required.

Thiopurines vs methotrexate: Comparing tolerability and discontinuation rates in the treatment of inflammatory bowel disease

BACKGROUND

There are safety concerns regarding immunomodulators (thiopurines and methotrexate) for treatment of inflammatory bowel disease (IBD).

AIM

To compare the long-term tolerability, and persistence of thiopurine and methotrexate therapy in IBD.

METHODS

A retrospective cohort study was performed at two hospitals between 1 January 2004 and 31 December 2016 for patients commenced on thiopurines or methotrexate for IBD. Treatment discontinuation rates, intolerances and disease activity were obtained from medical records.

RESULTS

There were 782 patients commenced on immunomodulator therapy; 244 (31%) on methotrexate with folate (67% subcutaneous therapy) and 538 (69%) on thiopurine (73% azathioprine). Median follow-up was 42 vs 47 months (P = 0.09). In patients on thiopurines, median 6-TGN was 298 pmol/8 x 10⁸ RBCs, while the median dose of methotrexate was 25 mg weekly. Methotrexate recipients had a higher rate of prior immunomodulator intolerance, were typically older and had a longer disease duration (54% vs 3%, median 43 vs 36 years, 6 vs 5 years, respectively, each P < 0.05). Overall, 208 (27%) discontinued therapy due to adverse events, (40% on methotrexate vs 19% on thiopurines, P < 0.001), including nausea (18% vs 4%), fatigue (7% vs 2%) and hepatotoxicity (8% vs 2%, each P < 0.001). Hospitalisations from adverse events (0.8% vs 0.9%) and serious infections (9% vs 12%), and deaths (1% vs 0%) were comparable between groups (all P > 0.05). Discontinuation due to adverse events occurred later in patients on methotrexate than on thiopurines (median 7 vs 5 months, P = 0.08).

CONCLUSION

Discontinuation of methotrexate occurred at rates twice that of dose-optimised thiopurine therapy.

A virtual clinic increases anti-TNF dose intensification success via a treat-to-target approach compared with standard outpatient care in Crohn's disease

BACKGROUND

Virtual clinics represent a novel model of care in inflammatory bowel disease. Their effectiveness in promoting high quality use of biologic therapy and facilitating a treat-to-target approach is unknown.

AIM

To evaluate clinical and process-driven outcomes in a virtual clinic compared to standard outpatient care amongst patients receiving intensified anti-TNF therapy for secondary loss of response.

METHODS

We performed a retrospective multi-centre, parallel, observational cohort study of Crohn's disease patients receiving intensified anti-TNF therapy for secondary loss of response. Objective assessments of disease activity and anti-TNF trough levels at secondary loss of response and during subsequent 6-month semesters, were compared longitudinally between virtual clinic and standard outpatient care cohorts. The primary endpoint was treatment success, with appropriateness of dose intensification, tight disease monitoring and treatment de-escalation representing secondary outcomes.

RESULTS

Of 149 patients with similar baseline characteristics, 69 were managed via a virtual clinic and 80 via standard outpatient care. There were higher rates of treatment success in the virtual clinic cohort (60.9 vs 35.0%, P < 0.002). Rates of appropriate dose intensification (82.6% vs 40.0%, P < 0.001), biomarker remission (faecal calprotectin P = 0.002), tight-disease monitoring (84.1% vs 28.8%, P < 0.001) and treatment de-escalation (21.3% vs 10.0%, P = 0.027) also favoured the virtual clinic cohort.

CONCLUSION

This study favoured a virtual clinic-led model-of-care over standard outpatient care in facilitating treatment success as part of an effective treat-to-target approach in Crohn's disease. A virtual clinic model-of-care also improved treatment outcomes and quality of use of intensified anti-TNF therapy through processes that promoted appropriate dose intensification and tight-disease monitoring, while encouraging more frequent dose de-escalation.

Therapeutic Drug Monitoring of Biologics During Induction to Prevent Primary Non-Response

Biologic therapies have revolutionized the management of inflammatory bowel disease [IBD], but primary and secondary non-responses occur in a significant proportion of patients. Therapeutic drug monitoring [TDM] now has an established role in the treatment algorithm for managing secondary loss of response to anti-tumour necrosis factor [anti-TNF] agents during maintenance therapy. Data to support the use of TDM in the management of secondary loss of response to vedolizumab and ustekinumab are emerging. The potential to prevent primary non-response to biologic agents during induction is of equal, and potentially greater, clinical importance. Again, most data supporting the use of 'proactive' TDM during induction pertains to the use of anti-TNF agents, but signals of efficacy for the use of TDM during induction with other biologic classes are now appearing. This review aims to summarize data on the use of TDM during induction to prevent pharmacokinetic primary non-response to all three classes of biologic therapy currently available for the treatment of IBD.

Review article: determination of the therapeutic range for therapeutic drug monitoring of adalimumab and infliximab in patients with inflammatory bowel disease

BACKGROUND

Clinical application of therapeutic drug monitoring (TDM) to optimise anti-TNF therapies in patients with IBD depends upon target ranges.

AIMS

To review methodology used to determine therapeutic ranges and critically compare and contrast its application to infliximab and adalimumab.

METHODS

A systematic review was performed, and relevant literature was summarised and critically examined.

RESULTS

Upper limits of the therapeutic range are determined by toxicity, a plateau response and cost. Lower limits are determined by optimal concentration on the target of action in vitro and/or in vivo, or by correlation of drug levels with clinical efficacy using area-under-receiver-operator-curve (AUROC) analysis. In 43 studies, there were huge variations in time at which infliximab and adalimumab levels were measured, the end-points used (clinical remission to mucosal healing), the clinical setting (active disease vs maintenance phase) and the reason for TDM (proactive vs reactive). In the maintenance phase for infliximab, lower trough limits 2.8-5.7 µg/mL are reported depending upon end-points used, with consistent AUROC 0.68-0.77. Adalimumab TDM targets are even less consistent with a lower limit 5.9-11.8 µg/mL (AUROC 0.66-0.83) in some studies, but no cut-off can be identified that is significantly associated with outcome in others, related to inherent pharmacokinetic and pharmacodynamic differences, and heterogeneity of study design.

CONCLUSIONS

Evidence for exposure-response relationship is stronger for infliximab than adalimumab. Due to heterogeneity in settings for drug level measurements, therapeutic ranges vary. These factors need to be taken into account when interpreting the evidence and extending this to therapeutic strategies for IBD patients.

Anti-TNF Therapy in Pregnant Women With Inflammatory Bowel Disease: Effects of Therapeutic Strategies on Disease Behavior and Birth Outcomes

BACKGROUND

Active inflammatory bowel disease (IBD) adversely affects pregnancy outcomes. Little is known about the risk of relapse after stopping anti-tumor necrosis factor (anti-TNF) treatment during pregnancy. We assessed the risk of relapse before delivery in women who discontinued anti-TNF treatment before gestational week (GW) 30, predictors of reduced infant birth weight, a marker associated with long-term adverse outcomes, and rates and satisfaction with counseling.

METHODS

Pregnant women with IBD receiving anti-TNF treatment were prospectively invited to participate in an electronic questionnaire carried out in 22 hospitals in Denmark, Australia, and New Zealand from 2011 to 2015. Risk estimates were calculated, and birth weight was investigated using t tests and linear regression.

RESULTS

Of 175 women invited, 153 (87%) responded. In women in remission, the relapse rate did not differ significantly between those who discontinued anti-TNF before GW 30 (1/46, 2%) compared with those who continued treatment (8/74, 11%; relative risk, 0.20; 95% confidence interval [CI], 0.02 to 1.56; P = 0.08). Relapse (P = 0.001) and continuation of anti-TNF therapy after GW 30 (P = 0.007) were independently associated with reduced mean birth weight by 367 g (95% CI, 145 to 589 g; relapse) and 274 g (95% CI, 77 to 471 g; anti-TNF exposure after GW 30). Of 134 (88%) women who received counseling, 116 (87%) were satisfied with the information provided.

CONCLUSIONS

To minimize fetal exposure in women in remission, discontinuation of anti-TNF before GW 30 seems safe. Relapse and continuation of anti-TNF therapy after GW 30 were each independently associated with lower birth weight, although without an increased risk for birth weight <2500 g. Most women received and were satisfied with counseling.

Comparison of Adalimumab Serum Drug Levels When Delivered by Pen Versus Syringe in Patients With Inflammatory Bowel Disease. An International, Multicentre Cohort Analysis

BACKGROUND

Adalimumab is administered via a pre-filled syringe or spring-loaded pen. In a previous study in Crohn's disease, higher drug levels were observed in syringe users. The aim of this study was to evaluate the impact of delivery device on adalimumab drug levels in patients with Crohn's disease.

METHODS

Consecutive Crohn's disease patients treated with maintenance adalimumab [40 mg fortnightly] were recruited from five centres. The first recorded drug level with matched clinical and biochemical markers of disease activity was compared between pen and syringe users.

RESULTS

Of 218 patients, 64% used pen, with a median faecal calprotectin 110 μg/g and serum C-reactive protein 4 mg/L. In comparison to pen, syringe users had higher albumin [39 vs 42 g/L; p = 0.016], lower Harvey-Bradshaw Index [2 vs 1; p = 0.017], and higher rates of concomitant immunomodulation [54% vs 71%; p = 0.014]. Drug levels were equivalent between pen and syringe users [median 5.3 vs 5.2 μg/ml; p = 0.584], even after controlling for disease activity and immunomodulation. Syringe users at Alfred Health had higher drug levels than pen [6.1 vs 4.5 μg/ml; p = 0.039]; a greater proportion achieved therapeutic levels [75% vs 44%; p = 0.045]. A higher proportion of pen users from Saint-Étienne had therapeutic levels [79% vs 42%; p = 0.027], yet no significant difference in drug levels [7.9 vs 4.5 μg/ml; p = 0.119].

CONCLUSIONS

Delivery device does not appear to significantly affect adalimumab drug levels. Given differences between study sites, studies evaluating administration education and technique are warranted.

Appropriate Therapeutic Drug Monitoring of Biologic Agents for Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Therapeutic drug monitoring (TDM) is widely available for biologic therapies in patients with inflammatory bowel disease (IBD). We reviewed current data and provided expert opinion regarding the clinical utility of TDM for biologic therapies in IBD.

METHODS

We used a modified Delphi method to establish consensus. A comprehensive literature review was performed regarding the use of TDM of biologic therapy in IBD and presented to international IBD specialists. Subsequently, 28 statements on the application of TDM in clinical practice were rated on a scale of 1 to 10 (1 = strongly disagree and 10 = strongly agree) by each of the panellists. Statements were accepted if 80% or more of the participants agreed with a score ≥7. The remaining statements were discussed and revised based on the available evidence followed by a second round of voting.

RESULTS

The panel agreed on 24 (86%) statements. For anti-tumor necrosis factor (anti-TNF) therapies, proactive TDM was found to be appropriate after induction and at least once during maintenance therapy, but this was not the case for the other biologics. Reactive TDM was appropriate for all agents both for primary non-response and secondary loss of response. The panellists also agreed on several statements regarding TDM and appropriate drug and anti-drug antibody (ADA) concentration thresholds for biologics in specific clinical scenarios.

CONCLUSION

Consensus was achieved towards the utility of TDM of biologics in IBD, particularly anti-TNF therapies. More data are needed especially on non-anti-TNF biologics to further define optimal drug concentration and ADA thresholds as these can vary depending on the therapeutic outcomes assessed.

A Personalized Approach to Managing Patients With an Ileal Pouch-Anal Anastomosis

Quality of life after ileal pouch-anal anastomosis (IPAA) surgery is generally good. However, patients can be troubled by pouch-related symptoms and pouch disorders that can be inflammatory, mechanical/surgical, and functional. Management of patients with IPAA begins with measures to maintain a healthy pouch such as optimizing pouch function, providing tailored advice on a healthy diet and lifestyle, screening for and addressing metabolic complications of IPAA, pouch surveillance, and risk stratification for risk of pouchitis and pouch failure. Pouchitis is the most common inflammatory disorder. Primary pouchitis is a spectrum currently classified into three progressive phases-an antibiotic-responsive, an antibiotic-dependent, and an antibiotic-refractory phase. It is predominately microbially mediated in acute antibiotic-responsive pouchitis and predominately immune mediated in chronic antibiotic-refractory pouchitis (CARP). Secondary prophylaxis is recommended for recurrent antibiotic-responsive and for antibiotic-dependent pouchitis. Secondary causes of antibiotic-refractory pouchitis should be ruled out before a diagnosis of CARP is made. CARP is best classified as primary sclerosing cholangitis associated, immunoglobulin G4-associated, and autoimmune. Primary sclerosing cholangitis-associated CARP can be treated with budesonide or oral vancomycin. Early recognition of immunoglobulin G4-associated pouchitis minimizes ineffective antibiotic use. Autoimmune CARP can be managed in a manner similar to UC. The current place of immunosuppressives in the treatment algorithm depends on availability and early access to biological agents. Vedolizumab and ustekinumab are the preferred first- and second-line biologics for autoimmune CARP owing to their efficacy, better side effect profile, and low immunogenicity and need for concomitant immunomodulatory therapy. Antitumor necrosis factor should be reserved for autoimmune CARP failing the above and for CD of the pouch. There are no guidelines for the surveillance of pouches for dysplasia. Incidence varies based on a patient's risk. Since incidence is low, a risk-stratified approach is recommended.

6-Thioguanine Nucleotide Levels Are Associated With Mucosal Healing in Patients With Crohn's Disease

BACKGROUND

Level of 6-thioguanine nucleotides (6-TGN) has been reported to be associated with clinical remission in patients with Crohn's disease (CD) receiving maintenance treatment with thiopurines. Whether 6-TGN levels are associated with mucosal healing (MH) has seldom been investigated. We aimed to assess the correlation between 6-TGN levels and MH in patients with CD.

METHODS

This was a retrospective, cross-sectional, observational, multicenter study of 119 patients with CD treated with thiopurines in 3 inflammatory bowel disease referral centers (France, Australia, and China) between June 2012 and April 2016. Established CD patients who underwent ileocolonoscopy during thiopurine treatment were included. MH was defined as simple endoscopic score-CD <3. Univariate and multivariable regression analyses were used to evaluate variables associated with MH.

RESULTS

The mean concentration of 6-TGN in the MH group was higher compared with that in the non-MH group (359.0 ± 226.7 pmol/8 × 108 red blood cell count [RBC] vs 277.1 ± 170.5 pmol/8 × 108 RBC; P = 0.017). The cutoff 6-TGN concentration of 397.3 pmol/8 × 108 RBC was 86.7% specific to MH, with a sensitivity of 35.3% and area under curve (AUC) of 0.631 (P = 0.010). On multivariable analysis, 6-TGN levels were associated with MH (odds ratio [OR], 3.287; 95% confidence interval [CI], 1.348-8.017; P = 0.009) whereas late initiation of AZA (longer duration from disease onset) was inversely associated with MH (OR, 0.972; 95% CI, 0.954-0.991; P = 0.004).

CONCLUSIONS

Higher 6-TGN levels are independently associated with a reduced rate of endoscopically active disease and a higher rate of mucosal healing in CD patients. Prospective studies of adequate sample size are required to confirm these findings.

Appropriateness of Combination Therapy for Patients With Inflammatory Bowel Diseases: One Size Still Does Not Fit All

Randomized controlled trials (RCTs) have demonstrated that therapies targeting tumor necrosis factor (TNF) and α₄β₇ integrin are effective when given as monotherapy in inducing and/or maintaining remission in patients with ulcerative colitis (UC) or Crohn's disease (CD), but data from RCTs are less clear on whether concomitant immunomodulator (IM) therapy confers additional benefit. In CD, RCT data are mixed,^1,2 as are results of systematic reviews and meta-analyses, showing no benefit overall,³ minimal benefit with individual agents,⁴ and comparative benefit over some monotherapies but not others.⁵ For example, concomitant azathioprine with infliximab is more effective than either drug alone in patients with CD naive to both drugs,² but whether combination therapy is more effective than monotherapy with infliximab in nonnaive patients, or with other approved biologic drugs in any population, remains unknown. In UC, RCTs have shown that the benefit may be limited to specific populations,⁶ whereas systematic reviews suggest no benefit at all.⁷.

Predicting response after infliximab salvage in acute severe ulcerative colitis

BACKGROUND AND AIM

Acute severe ulcerative colitis (ASUC) is a medical emergency requiring prompt therapeutic intervention. Although infliximab has been used as salvage therapy for over 15 years, clinical predictors of treatment success are lacking. We performed a retrospective analysis to identify factors that predict colectomy and may guide dose intensification.

METHODS

Fifty-four hospitalized patients received infliximab for ASUC at seven Australian centers (April 2014-May 2015). Follow-up was over 12 months. The data were primarily analyzed for predictors of colectomy. Accelerated (AI) versus standard (SI) infliximab induction strategies were also compared.

RESULTS

Of 54 patients identified, the overall colectomy rate was 15.38% (8/52) at 3 months and 26.92% (14/52) at 12 months. Two patients were lost to follow-up. There was a numerically higher colectomy rate in those treated with AI compared with SI (P = 0.3); however, those treated with AI had more severe biochemical disease. A C-reactive protein (CRP)/albumin ratio cut-off of 0.37 post-commencement of infliximab and before discharge was a significant predictor of colectomy with an area under receiver operating curve of 0.73. Pretreatment CRP and albumin levels were not predictive of colectomy. A Mayo Endoscopic Score of 2 had a 94% PPV for avoidance of colectomy following infliximab salvage.

CONCLUSIONS

The baseline Mayo Endoscopic Score and the CRP/albumin ratio following infliximab salvage are significant predictors of treatment response for ASUC and identify patients at high risk of colectomy. Whether this risk can be mitigated using infliximab dose intensification requires prospective evaluation before the CRP/albumin ratio can be integrated into ASUC management algorithms.

Therapeutic drug monitoring of vedolizumab in inflammatory bowel disease: current data and future directions

The introduction of vedolizumab, a lymphocyte adhesion inhibitor, has expanded the relatively limited therapeutic armamentarium available for Crohn's disease and ulcerative colitis. Despite its effectiveness, both primary nonresponse and secondary loss of response to vedolizumab do occur, as is observed with the use of anti-tumour necrosis factor (TNF) therapy. Further, in a proportion, onset of efficacy may be relatively slow. A large body of data support an exposure-response relationship with anti-TNF drug levels, which has led to therapeutic drug monitoring becoming incorporated into everyday clinical management. The influence of patient and disease factors on the pharmacokinetics of anti-TNF levels, including immunogenicity, has also been examined. The role of therapeutic drug monitoring with vedolizumab is less clear. This review summarizes the available evidence on the pharmacokinetics and pharmacodynamics of vedolizumab in inflammatory bowel disease and how drug levels, immunogenicity and other factors influence clinical outcomes. Vedolizumab clearance is increased with very high body weight and hypoalbuminaemia, but is not influenced by the addition of an immunomodulator. Immunogenicity is uncommon. α4β7 receptor saturation occurs at low serum vedolizumab drug levels, and measuring it alone is insufficient to predict clinical outcomes. Using quartile analysis of vedolizumab drug levels, there appears to be a modest exposure-response relationship during induction. Drug levels at week 6 of approximately >20 μg/ml have been shown to be associated with improved clinical outcomes, including subsequent mucosal healing rates during maintenance and avoiding the need to dose escalate due to lack of response. There are currently insufficient data to support the routine use of therapeutic drug monitoring during maintenance therapy. Further studies to elucidate the role of therapeutic drug monitoring of vedolizumab are needed.

Randomised clinical trial: efficacy, safety and dosage of adjunctive allopurinol in azathioprine/mercaptopurine nonresponders (AAA Study)

BACKGROUND

Thiopurine hypermethylation towards 6-methylmercaptopurine (6MMP) instead of 6-thioguanine nucleotides (6TGN) is associated with inefficacy in patients with IBD. Allopurinol reverses such hypermethylation.

AIMS

To prospectively determine efficacy of allopurinol-thiopurine combination and to compare 2 doses of allopurinol.

DESIGN

In a multicentre, double-blind trial, patients with clinically active or steroid-dependent IBD and thiopurine shunting were randomised to 50 or 100 mg/d allopurinol and 25% of their screening thiopurine dose, which was subsequently optimised, aiming for 6TGN of 260-500 pmol/8x10⁸ RBCs. The primary endpoint was steroid-free clinical remission at 24 weeks.

RESULTS

Of 73 patients, 39 (53% [95% CI 42-65]) achieved steroid-free remission, (54% with 50 mg/d and 53% with 100 mg/d). 81% were able to discontinue steroids. Therapeutic 6TGN levels were achieved in both groups. Final thiopurine doses were lower with 100 mg/d allopurinol (P < 0.005). 6MMP: 6TGN ratio decreased from mean 64 to 4 (P < 0.001), being higher with 50 mg/d (6 ± 1.83) than for 100 mg/d ([1 ± 0.16], P = 0.003). Three patients on 50 mg/d failed to sustain low ratios at 24 weeks. Toxicity was minimal; three patients on 50 mg/d allopurinol developed transient leukopenia. Alanine aminotransferase concentrations decreased (P < 0.001) similarly in both arms. Faecal calprotectin levels at study end were lower in patients who achieved the primary endpoint (median 171 [85-541] vs 821[110-5892] ug/g, P = 0.03).

CONCLUSIONS

Low-dose allopurinol-thiopurine combination safely reverses shunting and optimises 6TGN with associated improvement in disease activity. 100 mg/d allopurinol is preferable due to greater metabolite profile stability and lower thiopurine dose without additional toxicity.

Anti-TNF Re-induction Is as Effective, Simpler, and Cheaper Compared With Dose Interval Shortening for Secondary Loss of Response in Crohn's Disease

BACKGROUND AND AIMS

The optimal duration of dose-intensified therapy following secondary loss of response [LOR] to anti-tumour necrosis factor [TNF] therapy remains unclear. Anti-TNF re-induction involves a finite period of intensified therapy and may be a cost-effective means of re-capturing response. This study aimed to compare the efficacy, durability, and cost of anti-TNF re-induction and dose interval shortening [DIS] for secondary LOR in Crohn's disease [CD].

METHODS

This was a retrospective observational study in CD patients who developed secondary LOR to maintenance anti-TNF therapy, requiring subsequent re-induction and/or DIS. The primary outcome was treatment failure within 12 months. Secondary outcomes included factors associated with time to failure, disease activity, and incremental anti-TNF costs.

RESULTS

Of 423 patients with CD on anti-TNF therapy, 80 [19%] developed secondary LOR, with 33 and 55 patients undergoing subsequent anti-TNF re-induction and DIS, respectively. There was no significant difference in the incidence of treatment failure at 12 months following re-induction and DIS, respectively [p = 0.27]. Factors predictive of a longer time to failure included a higher baseline serum albumin, male sex, and thiopurine co-therapy [each p < 0.05], whereas higher baseline faecal calprotectin was associated with shorter time to failure. There was no significant difference in clinical remission or objective disease activity across both groups. The median incremental cost of re-induction and DIS was AUD 4 838 and AUD 13 190, respectively.

CONCLUSIONS

In patients with CD who develop secondary LOR, re-induction may represent an effective and less expensive first-line strategy, reserving dose intensification strategies such as DIS for non-responders.

Exploration of Predictive Biomarkers of Early Infliximab Response in Acute Severe Colitis: A Prospective Pilot Study

BACKGROUND

The outcomes of acute severe ulcerative colitis [ASUC] appear to be dependent on early intervention with the first and/or further infliximab [IFX] doses, although parameters to guide decision-making remain uncertain.

AIM

To assess whether serum/faecal IFX levels and inflammatory biomarkers early after IFX dose can predict ASUC outcomes.

METHODS

This prospective pilot study consecutively recruited inpatients with steroid-refractory ASUC, who then received 1-3 IFX rescue doses [5 mg/kg per dose] at the discretion of the treating clinician. Serum IFX, C-reactive protein [CRP], albumin and faecal calprotectin [FC] concentrations were measured daily as an inpatient, and then 7, 14, 28 and 42 days post-first IFX. Faecal IFX was measured 1 day post-IFX. The primary end point was clinical remission (partial Mayo [PM] = 0) and CRP ≤3 mg/l at 6 weeks. Secondary end points were 12-week clinical remission or colectomy during follow-up.

RESULTS

Of 24 ASUC patients with a median follow-up of 28 months [range 13-44], 10 [42%] achieved remission at 6 weeks, 12 [50%] achieved 12-week remission, six [25%] had colectomy. In total, 97% received either two or three IFX doses. Post-first dose, receiver-operator curve-derived cutoffs of the area-under-curve [AUC, Days 4-7] concentrations for serum IFX, FC and PM scores each predicted the primary end point with 100% sensitivity, and predicted future colectomy with 89-94% sensitivity. In multivariate analyses, faecal IFX >1 µg/g (odds ratio [OR] 0.04 [0.2, 0.9]), PM AUCd1-3 < 20 (OR 20.2 [1.01, 404], each P < 0.05), FC AUCd1-3 < 10000 µg/ml [OR 13.6 [0.6, 294], trend only, p = 0.09) were each associated with clinical and CRP remission [6 weeks].

CONCLUSIONS

In ASUC, post-first dose IFX, early assessment of serum/faecal IFX, calprotectin and PM scores can accurately predict future remission and colectomy, and thus potentially aid in decision-making, i.e. accelerated IFX dosing or surgical planning if/when needed.

Patchy colitis, and young age at diagnosis and at the time of surgery predict subsequent development of Crohn's disease after ileal pouch-anal anastomosis surgery for ulcerative colitis

BACKGROUND AND AIM

A proportion of patients having total proctocolectomy and ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) are later diagnosed with Crohn's disease (CD). The aim of this study was to identify preoperative and perioperative predictors for the subsequent development of CD in patients who had IPAA for presumed UC.

METHODS

A retrospective case-control study of patients undergoing IPAA surgery for presumed UC was undertaken. Cases were patients who had a revised diagnosis of CD after surgery. Preoperative and perioperative variables were examined and analyzed.

RESULTS

Fifteen cases were compared with 39 controls. Patients aged ≤25 years at initial UC diagnosis were more likely to develop CD compared to those aged >25 years (odds ratio, OR [95% confidence interval, CI]: 7.1 [1.6-31.3]; P = 0.01). Patients aged ≤30 years at the time of colectomy had an increased risk of subsequent development of CD compared to those aged >30 years (OR [95% CI]: 4.5 [1.3-16.0]; P = 0.02). Cases were more likely to have patchy colitis on their colectomy specimen (OR [95% CI]: 6.7 [1.1-41.8]; P = 0.04). There was no significant difference between groups regarding transmural inflammation, ileitis, or fissuring ulcers on colectomy specimens, or preoperative C-reactive protein (CRP), albumin, family history, and smoking status.

CONCLUSION

Predictors of the development of CD in the pouch include young age at diagnosis and at the time of surgery, and patchy colitis in the resected colon.

Examining maintenance care following infliximab salvage therapy for acute severe ulcerative colitis

BACKGROUND AND AIM

Data supporting the optimal maintenance drug therapy and strategy to monitor ongoing response following successful infliximab (IFX) induction, for acute severe ulcerative colitis (ASUC), are limited. We aimed to evaluate maintenance and monitoring strategies employed in patients post-IFX induction therapy.

METHODS

Patients in six Australian tertiary centers treated with IFX for steroid-refractory ASUC between April 2014 and May 2015 were identified via hospital IBD and pharmacy databases. Patients were followed up for 1 year with clinical data over 12 months recorded. Analysis was limited to patient outcomes beyond 3 months.

RESULTS

Forty one patients were identified. Five of the 41 (12%) patients underwent colectomy within 3 months, and one patient was lost to follow-up. Six of 35 (17%) of the remaining patients progressed to colectomy by 12 months. Maintenance therapy: Patients maintained on thiopurine monotherapy (14/35) versus IFX/thiopurine therapy (15/35) were followed up. Two of 15 (13%) patients who received combination maintenance therapy underwent a colectomy at 12 months, compared with 1/14 (7%) patients receiving thiopurine monotherapy (P = 0.610). Monitoring during maintenance: Post-discharge, thiopurine metabolites were monitored in 15/27 (56%); fecal calprotectin in 11/32 (34%); and serum IFX levels in 4/20 (20%). Twenty of 32 (63%) patients had an endoscopic evaluation after IFX salvage with median time to first endoscopy of 109 days (interquartile range 113-230).

CONCLUSION

Following IFX induction therapy for ASUC, the uptake of maintenance therapy in this cohort and strategies to monitor ongoing response were variable. These data suggest that the optimal maintenance and monitoring strategy post-IFX salvage therapy remains to be defined.