Therapeutic drug monitoring in inflammatory bowel disease: implementation, utilization, and barriers in clinical practice in Scandinavia.

BACKGROUND AND AIMS: Therapeutic drug monitoring (TDM) may optimize biologic and thiopurine therapies in inflammatory bowel disease (IBD). The study aimed to investigate implementation and utilization of TDM in Scandinavia. METHODS: A web-based questionnaire on the use of TDM was distributed to Scandinavian gastroenterologists via the national societies. RESULTS: In total, 297 IBD physicians prescribing biologic therapies, equally distributed between community and university hospitals, were included (response rate 42%) (Norway 118 (40%), Denmark 86 (29%), Sweden 50 (17%), Finland 33 (11%), Iceland 10 (3%)). Overall, TDM was applied during biologic therapies by 87%, and for TNF-inhibitors >90%. Among the users, reactive and proactive TDM were utilized by 90% and 63%, respectively. Danish physicians were significantly less inclined to use TDM compared to other Scandinavian countries; (58% vs 98%); OR 0.03 [0.01-0.09], p < 0.001). Reactive TDM was commonly applied at primary (74%) and secondary (99%) treatment failure. Proactive TDM was used by 80% during maintenance therapy and 56% during induction and more commonly utilized in Norway (p < 0.001), and by physicians managing >10 IBD patients/week (p = 0.005). TDM scenarios were interpreted in accord with available evidence but with discrepancies for proactive TDM. The main barriers to TDM were lack of guidelines (51%) and time lag between sampling and results (49%). TDM of thiopurines was routinely used by 87%. CONCLUSION: TDM of biologic and thiopurine therapies has been broadly implemented into clinical practice in Scandinavia. However, physicians call for TDM guidelines detailing indications and interpretations of test results along with improved test response times.

Effects of Tumor Necrosis Factor Antagonists in Patients With Primary Sclerosing Cholangitis.

BACKGROUND & AIMS: Few patients with primary sclerosing cholangitis (PSC) and inflammatory bowel diseases (IBDs) are exposed to tumor necrosis factor (TNF) antagonists because of the often mild symptoms of IBD. We assessed the effects of anti-TNF agents on liver function in patients with PSC and IBD, and their efficacy in treatment of IBD. METHODS: We performed a retrospective analysis of 141 patients with PSC and IBD receiving treatment with anti-TNF agents (infliximab or adalimumab) at 20 sites (mostly tertiary-care centers) in Europe and North America. We collected data on the serum level of alkaline phosphatase (ALP). IBD response was defined as either endoscopic response or, if no endoscopic data were available, clinical response, as determined by the treating clinician or measurements of fecal calprotectin. Remission was defined more stringently as endoscopic mucosal healing. We used linear regression analysis to identify factors associated significantly with level of ALP during anti-TNF therapy. RESULTS: Anti-TNF treatment produced a response of IBD in 48% of patients and remission of IBD in 23%. There was no difference in PSC symptom frequency before or after drug exposure. The most common reasons for anti-TNF discontinuation were primary nonresponse of IBD (17%) and side effects (18%). At 3 months, infliximab-treated patients had a median reduction in serum level of ALP of 4% (interquartile range, reduction of 25% to increase of 19%) compared with a median 15% reduction in ALP in adalimumab-treated patients (interquartile range, reduction of 29% to reduction of 4%; P = .035). Factors associated with lower ALP were normal ALP at baseline (P < .01), treatment with adalimumab (P = .090), and treatment in Europe (P = .083). CONCLUSIONS: In a retrospective analysis of 141 patients with PSC and IBD, anti-TNF agents were moderately effective and were not associated with exacerbation of PSC symptoms or specific side effects. Prospective studies are needed to investigate the association between use of adalimumab and reduced serum levels of ALP further.

Switching from originator infliximab to biosimilar CT-P13 compared with maintained treatment with originator infliximab (NOR-SWITCH): a 52-week, randomised, double-blind, non-inferiority trial.

BACKGROUND: TNF inhibitors have improved treatment of Crohn's disease, ulcerative colitis, spondyloarthritis, rheumatoid arthritis, psoriatic arthritis, and chronic plaque psoriasis, but are expensive therapies. The aim of NOR-SWITCH was to examine switching from originator infliximab to the less expensive biosimilar CT-P13 regarding efficacy, safety, and immunogenicity. METHODS: The study is a randomised, non-inferiority, double-blind, phase 4 trial with 52 weeks of follow-up. Adult patients on stable treatment with infliximab originator treated in a hospital setting for at least 6 months were eligible for participation. Patients with informed consent were randomised in a 1:1 ratio to either continued infliximab originator or to switch to CT-P13 treatment, with unchanged dosing regimen. Data were collected at infusion visits in 40 Norwegian study centres. Patients, assessors, and patient care providers were masked to treatment allocation. The primary endpoint was disease worsening during 52-week follow-up. 394 patients in the primary per-protocol set were needed to show a non-inferiority margin of 15%, assuming 30% disease worsening in each group. This trial is registered with ClinicalTrials.gov, number NCT02148640. FINDINGS: Between Oct 24, 2014, and July 8, 2015, 482 patients were enrolled and randomised (241 to infliximab originator, 241 to CT-P13 group; one patient was excluded from the full analysis and safety set for CT-P13) and 408 were included in the per-protocol set (202 in the infliximab originator group and 206 in the CT-P13 group). 155 (32%) patients in the full analysis set had Crohn's disease, 93 (19%) had ulcerative colitis, 91 (19%) had spondyloarthritis, 77 (16%) had rheumatoid arthritis, 30 (6%) had psoriatic arthritis, and 35 (7%) had chronic plaque psoriasis. Disease worsening occurred in 53 (26%) patients in the infliximab originator group and 61 (30%) patients in the CT-P13 group (per-protocol set; adjusted treatment difference -4·4%, 95% CI -12·7 to 3·9). The frequency of adverse events was similar between groups (for serious adverse events, 24 [10%] for infliximab originator vs 21 [9%] for CT-P13; for overall adverse events, 168 [70%] vs 164 [68%]; and for adverse events leading to discontinuation, nine [4%] vs eight [3%], respectively). INTERPRETATION: The NOR-SWITCH trial showed that switching from infliximab originator to CT-P13 was not inferior to continued treatment with infliximab originator according to a prespecified non-inferiority margin of 15%. The study was not powered to show non-inferiority in individual diseases. FUNDING: Norwegian Ministry of Health and Care Services.

Risk factors and prognosis for recurrent primary sclerosing cholangitis after liver transplantation: a Nordic Multicentre Study.

OBJECTIVES: The risk for recurrent primary sclerosing cholangitis (rPSC) after liver transplantation is associated with inflammatory bowel disease (IBD). We assessed the frequency of rPSC and studied risk factors for recurrent disease with special focus on IBD. We also evaluated the importance of rPSC for prognosis. MATERIALS AND METHODS: All liver transplanted PSC patients in the Nordic countries between 1984 and 2007 (n = 440), identified by the Nordic Liver Transplant Registry, were studied. Data were retrieved from patients' chart reviews. Multivariable Cox regression models were used to calculate risk factors for rPSC and death. RESULTS: Of the 440 patients with a follow-up time after liver transplantation of 3743 patient years, rPSC was diagnosed in 19% (n = 85). Colectomy before liver transplantation was associated with a reduced risk of rPSC (HR 0.49; 95% CI, 0.26-0.94, p = 0.033). Neither high IBD activity nor presence of IBD flares before or after liver transplantation was associated with rPSC. Treatment with tacrolimus was an independent risk factor associated with increased risk for rPSC (HR, 1.81; 95% CI, 1.15-2.86, p = 0.010). The risk of dying or needing a re-transplantation after rPSC was increased in all age groups, but highest in patients transplanted before 40 years of age (HR 7.3; 95% CI, 4.1-12.8, p = 0.0001). CONCLUSIONS: This study confirms that colectomy before liver transplantation is associated with a decreased risk of rPSC. Inflammatory activity of IBD was not associated with the risk of rPSC. Tacrolimus was an independent risk factor for PSC recurrence and its use as first line immunosuppression in PSC needs further study.

No Evidence That Azathioprine Increases Risk of Cholangiocarcinoma in Patients With Primary Sclerosing Cholangitis.

BACKGROUND & AIMS: Patients with primary sclerosing cholangitis (PSC) are at increased risk for developing cholangiocarcinoma (CCA). Patients with PSC also can have inflammatory bowel diseases (IBDs) or features of autoimmune hepatitis (AIH), and therefore are treated with azathioprine. Azathioprine has been associated with an increased risk for malignancy, therefore we investigated whether azathioprine use affects the risk of CCA in persons with PSC. METHODS: We performed a retrospective study of well-defined patients with PSC using data collected from 3 large-volume, tertiary care centers in Germany and Norway. We analyzed data from 638 patients (70% men; 5900 patient-years of follow-up evaluation); 91 patients had received azathioprine therapy (considered to be effective at 90 days after first intake). Risk analysis was performed using the Cox proportional hazard model when risks competing with study end points were present. RESULTS: Of patients who received azathioprine treatment, 3.3% developed CCA, compared with 6.8% of patients without azathioprine treatment. However, azathioprine did not significantly affect the risk for CCA (hazard ratio, 0.96; 95% confidence interval, 0.29-3.13; P = .94). The only factor associated with an increased risk of CCA was age 35 years or older at PSC diagnosis (hazard ratio, 3.87; 95% confidence interval, 1.96-7.67; P < .01). Patient sex, concomitant IBD, or AIH did not affect the risk of CCA. Overall, the cumulative 10-year incidence of CCA was 4.6% and the cumulative 15-year incidence was 7.7%. CONCLUSIONS: A retrospective analysis of patients with PSC treated at tertiary centers in Europe found no evidence that azathioprine significantly affects the risk of CCA. Azathioprine therefore should not be withheld from patients with PSC and concomitant IBD and/or AIH.

A Cross-Sectional Study of the Prevalence of Gastrointestinal Symptoms and Pathology in Patients With Common Variable Immunodeficiency.

OBJECTIVES: The objective of this study was to study the prevalence of gastrointestinal (GI) symptoms and histopathology in patients with common variable immunodeficiency (CVID) as well as linking the findings to GI infections and markers of systemic immune activation. METHODS: In this cross-sectional study, we addressed GI symptoms in 103 patients and GI histopathological findings in 53 patients who underwent upper and lower endoscopic examination. The most frequent histopathological findings were linked to GI symptoms, B-cell phenotype, and markers of systemic immune activation (soluble (s)CD14, sCD25, and sCD163). Microarray analysis compared "celiac-like disease" in CVID to celiac disease. Screening for selected bacterial and viral infections in fecal samples and gut mucosal biopsies was performed. RESULTS: The main findings of this study were as follows: most common GI symptoms were bloating (34%), pain (30%), and diarrhea (26%). The most frequent histopathological findings were increased intraepithelial lymphocytes in the descending part of the duodenum, i.e., "celiac-like disease" (46% of patients), decreased numbers of plasma cells in GI tract mucosa (62%), and lymphoid hyperplasia (38%), none of which were associated with GI symptoms. Reduced plasma cells in GI mucosa were associated with B-cell phenotypic characteristics of CVID, and increased serum levels of sCD14 (P=0.025), sCD25 (P=0.01), and sCD163 (P=0.04). Microarray analyses distinguished between CVID patients with "celiac-like disease" and celiac disease. Positive tests for bacterial and viral infections were scarce both in fecal samples and gut mucosal biopsies, including PCR test for norovirus in biopsy specimens (0 positive tests). CONCLUSIONS: In conclusion, GI pathology is common in CVID, but does not necessarily cause symptoms. However, reduced plasma cells in GI mucosa were linked to systemic immune activation, "celiac-like disease" in CVID and true celiac disease appear to be different disease entities, as assessed by gene expression, and infections (including norovirus) are rarely a cause of the CVID enteropathy.

Colitis ameliorates cholestatic liver disease via suppression of bile acid synthesis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by chronic inflammation and progressive fibrosis of the biliary tree. The majority of PSC patients suffer from concomitant inflammatory bowel disease (IBD), which has been suggested to promote disease development and progression. However, the molecular mechanisms by which intestinal inflammation may aggravate cholestatic liver disease remain incompletely understood. Here, we employ an IBD-PSC mouse model to investigate the impact of colitis on bile acid metabolism and cholestatic liver injury. Unexpectedly, intestinal inflammation and barrier impairment improve acute cholestatic liver injury and result in reduced liver fibrosis in a chronic colitis model. This phenotype is independent of colitis-induced alterations of microbial bile acid metabolism but mediated via hepatocellular NF-κB activation by lipopolysaccharide (LPS), which suppresses bile acid metabolism in-vitro and in-vivo. This study identifies a colitis-triggered protective circuit suppressing cholestatic liver disease and encourages multi-organ treatment strategies for PSC.

Immunogenicity and Safety of Standard and Third-Dose SARS-CoV-2 Vaccination in Patients Receiving Immunosuppressive Therapy.

OBJECTIVE: Immunogenicity and safety following receipt of the standard SARS-CoV-2 vaccination regimen in patients with immune-mediated inflammatory diseases (IMIDs) are poorly characterized, and data after receipt of the third vaccine dose are lacking. The aim of the study was to evaluate serologic responses and adverse events following the standard 2-dose regimen and a third dose of SARS-CoV-2 vaccine in IMID patients receiving immunosuppressive therapy. METHODS: Adult patients receiving immunosuppressive therapy for rheumatoid arthritis, spondyloarthritis, psoriatic arthritis, Crohn's disease, or ulcerative colitis, as well as healthy adult controls, who received the standard 2-dose SARS-CoV-2 vaccination regimen were included in this prospective observational study. Analyses of antibodies to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein were performed prior to and 2-4 weeks after vaccination. Patients with a weak serologic response, defined as an IgG antibody titer of ≤100 arbitrary units per milliliter (AU/ml) against the receptor-binding domain of the full-length SARS-Cov-2 spike protein, were allotted a third vaccine dose. RESULTS: A total of 1,505 patients (91%) and 1,096 healthy controls (98%) had a serologic response to the standard regimen (P < 0.001). Anti-RBD antibody levels were lower in patients (median 619 AU/ml interquartile range [IQR] 192-4,191) than in controls (median 3,355 AU/ml [IQR 896-7,849]) (P < 0.001). The proportion of responders was lowest among patients receiving tumor necrosis factor inhibitor combination therapy, JAK inhibitors, or abatacept. Younger age and receipt of messenger RNA-1273 vaccine were predictors of serologic response. Of 153 patients who had a weak response to the standard regimen and received a third dose, 129 (84%) became responders. The vaccine safety profile among patients and controls was comparable. CONCLUSION: IMID patients had an attenuated response to the standard vaccination regimen as compared to healthy controls. A third vaccine dose was safe and resulted in serologic response in most patients. These data facilitate identification of patient groups at risk of an attenuated vaccine response, and they support administering a third vaccine dose to IMID patients with a weak serologic response to the standard regimen.

Humoral and cellular immune responses to two and three doses of SARS-CoV-2 vaccines in rituximab-treated patients with rheumatoid arthritis: a prospective, cohort study.

BACKGROUND: In rituximab-treated patients with rheumatoid arthritis, humoral and cellular immune responses after two or three doses of SARS-CoV-2 vaccines are not well characterised. We aimed to address this knowledge gap. METHODS: This prospective, cohort study (Nor-vaC) was done at two hospitals in Norway. For this sub-study, we enrolled patients with rheumatoid arthritis on rituximab treatment and healthy controls who received SARS-CoV-2 vaccines according to the Norwegian national vaccination programme. Patients with insufficient serological responses to two doses (antibody to the receptor-binding domain [RBD] of the SARS-CoV-2 spike protein concentration <100 arbitrary units [AU]/mL) were allotted a third vaccine dose. Antibodies to the RBD of the SARS-CoV-2 spike protein were measured in serum 2-4 weeks after the second and third doses. Vaccine-elicited T-cell responses were assessed in vitro using blood samples taken before and 7-10 days after the second dose and 3 weeks after the third dose from a subset of patients by stimulating cryopreserved peripheral blood mononuclear cells with spike protein peptides. The main outcomes were the proportions of participants with serological responses (anti-RBD antibody concentrations of ≥70 AU/mL) and T-cell responses to spike peptides following two and three doses of SARS-CoV-2 vaccines. The study is registered at ClinicalTrials.gov, NCT04798625, and is ongoing. FINDINGS: Between Feb 9, 2021, and May 27, 2021, 90 patients were enrolled, 87 of whom donated serum and were included in our analyses (69 [79·3%] women and 18 [20·7%] men). 1114 healthy controls were included (854 [76·7%] women and 260 [23·3%] men). 49 patients were allotted a third vaccine dose. 19 (21·8%) of 87 patients, compared with 1096 (98·4%) of 1114 healthy controls, had a serological response after two doses (p<0·0001). Time since last rituximab infusion (median 267 days [IQR 222-324] in responders vs 107 days [80-152] in non-responders) and vaccine type (mRNA-1273 vs BNT162b2) were significantly associated with serological response (adjusting for age and sex). After two doses, 10 (53%) of 19 patients had CD4+ T-cell responses and 14 (74%) had CD8+ T-cell responses. A third vaccine dose induced serological responses in eight (16·3%) of 49 patients, but induced CD4+ and CD8+ T-cell responses in all patients assessed (n=12), including responses to the SARS-CoV-2 delta variant (B.1.617.2). Adverse events were reported in 32 (48%) of 67 patients and in 191 (78%) of 244 healthy controls after two doses, with the frequency not increasing after the third dose. There were no serious adverse events or deaths. INTERPRETATION: This study provides important insight into the divergent humoral and cellular responses to two and three doses of SARS-CoV-2 vaccines in rituximab-treated patients with rheumatoid arthritis. A third vaccine dose given 6-9 months after a rituximab infusion might not induce a serological response, but could be considered to boost the cellular immune response. FUNDING: The Coalition for Epidemic Preparedness Innovations, Research Council of Norway Covid, the KG Jebsen Foundation, Oslo University Hospital, the University of Oslo, the South-Eastern Norway Regional Health Authority, Dr Trygve Gythfeldt og frues forskningsfond, the Karin Fossum Foundation, and the Research Foundation at Diakonhjemmet Hospital.

Therapeutic drug monitoring of infliximab compared to standard clinical treatment with infliximab: study protocol for a randomised, controlled, open, parallel-group, phase IV study (the NOR-DRUM study).

BACKGROUND: Infliximab (INX) and other tumour necrosis factor inhibitors (TNFi) have revolutionised the treatment of several immune mediated inflammatory diseases. Still, many patients do not respond sufficiently to therapy or lose efficacy over time. The large interindividual variation in serum drug concentrations on standard doses and the development of anti-drug antibodies are thought to be major reasons for treatment failures. Therapeutic drug monitoring (TDM), an individualised treatment strategy based on systematic assessments of serum drug concentrations, has been proposed as a clinical tool to optimise efficacy of INX treatment. TDM seems reasonable both from a clinical and an economical point of view, but the effectiveness of this treatment strategy has not yet been demonstrated in randomised clinical trials. The NORwegian DRUg Monitoring study (NOR-DRUM) aims to assess the effectiveness of TDM, both with regard to the achievement of remission in patients starting INX treatment (part A) as well as to maintain disease control in patients on INX treatment (part B). METHODS: The NOR-DRUM study is a randomised, open, controlled, parallel-group, comparative, multi-centre, national, superiority, phase IV study with two separate parts, NOR-DRUM A and NOR-DRUM B. Patients with rheumatoid arthritis, psoriatic arthritis, spondyloarthritis, ulcerative colitis, Crohn's disease and psoriasis are included. In both study parts participants are randomised 1:1 to either TDM of infliximab (intervention group) or to standard treatment with infliximab without knowledge of drug levels or ADAb status (control group). NOR-DRUM A will include 400 patients starting INX therapy. The primary outcome is remission at 30 weeks. In NOR-DRUM B, 450 patients on maintenance treatment with INX will be included. The primary endpoint is occurrence of disease worsening during the 52-week study period. DISCUSSION: As the first trial to assess the effectiveness, safety and cost-effectiveness of TDM in patients receiving TNFi for a range of immune mediated inflammatory diseases, we hope that the NOR-DRUM study will contribute to the advancement of evidence based personalised treatment with biological medicines. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03074656. Registered on 090317.

Efficacy and Safety of CT-P13 in Inflammatory Bowel Disease after Switching from Originator Infliximab: Exploratory Analyses from the NOR-SWITCH Main and Extension Trials.

BACKGROUND: The NOR-SWITCH main and extension trials demonstrated that switching from originator to biosimilar infliximab (CT-P13) is efficacious and safe across six diseases. However, a subgroup analysis of Crohn's disease (CD) in the main trial displayed a close to significant difference favouring originator infliximab, and more scientific data have therefore been requested. OBJECTIVE: The aim was to assess treatment efficacy, safety, and immunogenicity in an explorative subgroup analysis in CD and ulcerative colitis (UC) in the NOR-SWITCH trials. PATIENTS AND METHODS: The 52-week, randomised, non-inferiority, double-blind, multicentre, phase 4 NOR-SWITCH study was followed by a 26-week open extension trial where all patients received treatment with CT-P13. Treatment efficacy, safety, and immunogenicity in CD and UC were assessed throughout the 78-week study period. RESULTS: The main and extension trials included 155 and 93 patients with CD and 93 and 80 patients with UC, respectively. Demographic and baseline characteristics were comparable in both treatment arms within patient groups. There were no differences in the main and extension trials regarding changes in activity indices, C-reactive protein, faecal calprotectin, patient's and physician's global assessment of disease activity and patient-reported outcome measures in CD and UC. Moreover, comparable results were also demonstrated for trough serum levels, presence of anti-drug antibodies, and reported adverse events. CONCLUSION: Efficacy, safety, and immunogenicity of both the originator and biosimilar infliximab were comparable in CD and UC in the NOR-SWITCH main and extension trials. These explorative subgroup analyses confirm that there are no significant concerns related to switching from originator infliximab to CT-P13 in CD and UC. TRIAL REGISTRATION: ClinicalTrials.gov, number NCT02148640.

Paucity of mycobacteria in mucosal bowel biopsies from adults and children with early inflammatory bowel disease.

BACKGROUND: The presence of Mycobacterium avium subspecies paratuberculosis (MAP) has previously been inferred in the genesis of Crohn's disease (CD), and a higher incidence of MAP PCR positivity has been demonstrated in the gut and peripheral blood of CD patients than in healthy individuals. The objective of this prospective study was to assess the potential etiological role of MAP in the pathogenesis of CD. METHODS: The presence of mycobacteria was assessed in bowel biopsies from newly diagnosed, treatment naïve Norwegian patients with IBD, including CD and ulcerative colitis (UC), as compared to a hospital-based cohort of CD and UC patients. Biopsies were collected from the small and large bowel in 354 individuals with suspected IBD. Detection of mycobacteria was performed by long-term cultivation in combination with direct detection by MAP IS900-specific PCR. RESULTS: Among the specimens included from the patients with early IBD, samples from only two of the patients with CD (2.7%) and two of the non-IBD controls (1.5%) exhibited a positive growth signal. None of the CD patients and only one of the non-IBD controls was MAP PCR positive. Only the single PCR positive non-IBD control was also mycobacterial culture positive with Mycobacterium avium subsp. hominissuis. In the referral patients with long-term IBD, the prevalence of growth signal and MAP PCR positivity was higher (52 and 9%, respectively). CONCLUSIONS: These findings demonstrate the paucity of MAP in the gut of treatment naïve CD patients. This study does not provide evidence for a role of MAP in early IBD.