5-aminosalicylate maintenance is not superior to no maintenance in patients with newly diagnosed Crohn's disease-A nationwide cohort study.

BACKGROUND: 5-aminosalicylates (5-ASA) are widely used in Crohn's disease (CD) despite guidelines advising otherwise. We aimed to assess in nationwide study the outcomes of first-line 5-ASA maintenance therapy (5-ASA-MT) compared with no maintenance treatment (no-MT) in patients with newly diagnosed CD. METHODS: We utilised data from the epi-IIRN cohort, including all patients with CD diagnosed in Israel between 2005 and 2020. Propensity score (PS) matching was utilised to compare outcomes in the 5-ASA-MT versus no-MT groups. RESULTS: Of the 19,264 patients diagnosed with CD, 8610 (45%) fulfilled the eligibility criteria (3027 [16%] received 5-ASA-MT and 5583 [29%] received no-MT). Both strategies declined over the years; 5-ASA-MT from 21% of CD patients diagnosed in 2005 to 11% in 2019 (p < 0.001) and no-MT from 36% to 23% (p < 0.001). The probability of maintaining therapy at 1, 3 and 5 years from diagnosis: 5-ASA-MT-78%, 57% and 47% and no-MT-76%, 49% and 38% respectively (p < 0.001). PS analysis successfully matched 1993 pairs of treated and untreated patients and demonstrated comparable outcomes of time to: biologic (p = 0.2), steroid dependency (p = 0.9), hospitalisation (p = 0.5) and CD-related surgery (p = 0.1). Rates of acute kidney injury (5.2% vs. 3.3%; p < 0.001) and pancreatitis (2.4% vs. 1.8%; p = 0.03) were higher in the 5-ASA-MT group compared with the no-MT group but after PS matching the rates of adverse events were similar. CONCLUSION: First-line 5-ASA monotherapy was not superior to no-MT but associated with a slightly higher rates of adverse events, while both strategies have declined over the years. These findings suggest that a subset of patients with mild CD may be offered a watchful waiting approach.

Risk of consecutive immunogenic failure in switchers of anti-tumor necrosis factor alpha among patients with inflammatory bowel diseases.

BACKGROUND: Evidence regarding the risk of immunogenicity in patients with inflammatory bowel disease (IBD) who switched anti-tumor necrosis factor alpha (anti-TNFα) therapies to a subsequent anti-TNFα (either infliximab or adalimumab) is conflicting. We aimed to assess the risk of consecutive immunogenicity to anti-TNFα in a large cohort of patients. METHODS: This was a multicenter retrospective study. Medical records of adult and pediatric IBD switchers who had pharmacokinetic data for both agents between 2014 and 2020 were retrieved. Data including age, sex, disease type, duration of therapies, and concomitant use of immunomodulators (IMMs) were recorded. RESULTS: Overall, 164 patients were included [52% female; 88% Crohn's disease; mean age = 24.4 ± 14.6 years; 108 (66%) switched from infliximab to adalimumab and 56 (34%) vice versa]; 120 (73.1%) patients switched due to an immunogenic failure. Among patients switching therapy from infliximab to adalimumab due to an immunogenic failure immunogenicity to infliximab was significantly associated with consecutive immunogenicity to adalimumab (p = 0.026). Forthy four out of 120 patients (36.6%) with an immunogenic failure to the first anti-TNFα started an IMM with the second anti-TNFα. This combination with IMM was not associated with reduction of consecutive immunogenicity (p = 0.31), but it was associated with longer drug retention (p = 0.007). Multivariate analysis demonstrated that older age at second anti-TNFα, adjusted to the chronology of therapy and sex, was associated with increased immunogenicity to the second anti-TNFα. CONCLUSION: Patients with IBD who switch from infliximab to adalimumab following an immunogenic failure are at increased risk for consecutive immunogenicity to adalimumab. IMM use after a switch prolongs drug retention.