Society: AGA

Background
Switching from originator to biosimilar infliximab (IFX) is effective and safe. However, data on multiple switching are scarce. The Edinburgh IBD unit has undertaken three switch programmes: (1) Remicade to CT-P13 (2016), (2) CT-P13 to SB2 (2020), and (3) SB2 to CT-P13 (2021). The primary endpoint of this study was to assess CT-P13 persistence following switch from SB2. Secondary endpoints included persistence stratified by the number of biosimilar switches (single, double and triple), effectiveness and safety.
Methods
We performed a prospective, observational, cohort study. All adult IBD patients on IFX biosimilar SB2 underwent an elective switch to CT-P13. Patients were reviewed in a virtual biologic clinic with protocol driven collection of clinical disease activity, CRP, faecal calprotectin (FC), IFX trough / antibody levels, and drug survival.
Results
297 patients (CD n=196 [66%], UC/IBDU n=101, [34%]) were switched. This was the third, second and first IFX switch for 67 /297 (22.5%), 138 /297 (46.5%) and 92 /297 (31%) of the cohort respectively. Patients who underwent multiple IFX biosimilar switches had longer disease duration (p=0.0001) and IFX duration (p=0.0001) and were less often on combination therapy with an immunomodulator (p=0.0001).
90.6% of patients remained on IFX during a median follow-up of 7.5 months [6.8-8.1] (figure 1). The number of switches was not independently associated with IFX persistence after adjusting for confounders (table 1). Clinical (p=0.77), biochemical (CRP ≤5mg/mL; p=0.75) and faecal biomarker (FC<250µg/g; p=0.63) remission were comparable at baseline, week 12 and week 24.
Conclusion
Multiple successive switches from IFX originator to biosimilars are effective and safe in patients with IBD, irrespective of the number of IFX switches.

Recently, a subcutaneous formulation of biosimilar infliximab (CT-P13) (SC-IFX) has been approved for inflammatory bowel disease (IBD). Aim: to evaluate efficacy, safety, pharmacokinetics and patient experience following a switching to SC-IFX in patients who are in clinical remission on IV-IFX maintenance treatment. Methods: Multicentre, descriptive, and observational study including Crohn’s disease (CD) and ulcerative colitis (UC) patients who were going to be changed from IV-IFX to SC-IFX on the ENEIDA registry (a large, prospectively maintained database of the Spanish Working Group in IBD–GETECCU). All patients were on clinical and biological remission at least 24 weeks before changing. Demographic and disease data, clinical activity (Harvey-Bradshaw index for CD and mayo index for UC), analytical data (C reactive protein (CRP) and fecal calprotectin (FC), as well as trough levels were collected at baseline, at 12 and 24 weeks. Results:
One hundred and fifty-five patients were included: 54 UC (35%) and 91 (65%) CD; 44% women and 56% men; age 45.5 years (32-55). IV-IFX was mainly administered due to active disease (72%) and perianal disease (7%) and during 32 months [range 14-56]. Pre-switch, 78 (50.3%) were on 8-weekly dosing of IV-IFX, 77 (49.7%) were with intensification dose and the half (50.3%) were on concomitant immunomodulatory therapy. SC-IFX was mainly switching by COVID-19 pandemic (60%), to increase through levels (15%) or patient request (25%). The majority of patients (140, 90%) remained with standard dose, 8 (5%) required dose intensification (120 mg weekly in 4 and 240 mg every 2 weeks in 4) and 7 (4.5%) had successful de-escalation (120 mg every 3 weeks in 4 and 120 mg every 4 weeks in 3). Clinical indices, CRP levels and FC remained unchanged (Figure). Median SC-IFX levels significantly increased from baseline of 4.5 μg/dl [range 2.6-9.2] to 14 μg/dl [range 9.5-16.2] at 12 weeks and 13.2 μg/dl [range 10.4-19.7] at 24 weeks No factors (immunossupresor, body mass index, disease location) were associated with the increase of IFX trough levels. During 24 weeks of follow-up, 16 of the 78 (20.5%) patients stopped immunosuppressant treatment. The adverse events were recorded in 9 patients (5.8%), 4 (2.6%) were hospitalized and 4 (2.6%) had surgery (one of them for perianal disease). Nine patients (5.8%) stopped SC-IFX (1 primary failure, 2 loss of response, 4 adverse events, 1 voluntarily, and 1 surgery). Conclusion: The switch from IV to SC IFX maintains clinical remission safely in IBD, offers higher drug levels and a good patient acceptance. However, the significance of higher drug levels with SC-IFX requires further exploration.

Objective: Tumor necrosis factor–like cytokine 1A (TL1A) regulates pro-inflammatory cytokines and fibrosis. PRA023 is an anti-TL1A monoclonal antibody in development for multiple inflammatory/fibrotic diseases incorporating a precision approach with a predictive genetic-based diagnostic (Dx) tool. This placebo-controlled, double-blind phase 2 study assessed efficacy and safety of PRA023 induction treatment in adults with moderately to severely active ulcerative colitis (UC).
Methods: Patients with a modified Mayo score (mMS) of 4 to 9, centrally read endoscopy subscore of ≥2, rectal bleeding subscore of ≥1, and history of insufficient response, loss of response, and/or intolerance to conventional and/or advanced therapies (≤4 advanced agents from ≤3 classes allowed) were eligible. Patients were stratified by prior biologic exposure and Dx status and randomized 1:1 to placebo or intravenous PRA023 (1000 mg on day 1, 500 mg at weeks 2, 6, and 10). The primary endpoint was clinical remission per mMS at week 12. Analyses of ranked secondary endpoints were multiplicity-controlled.
Results: Of the 135 patients, 60/67 (89.6%) in the placebo arm and 68/68 (100%) in the PRA023 arm completed the 12-week induction period. Baseline characteristics were similar (Table 1A). A significantly greater proportion of patients who received PRA023 achieved the primary endpoint of clinical remission (26.5% PRA023 vs 1.5% placebo, Δ25.0%, p<0.0001) at week 12 (Table 1B). All ranked secondary endpoints for cohort 1 significantly favored drug relative to placebo, including symptomatic remission (19.1% PRA023 vs 6.0% placebo, Δ13.1%, p=0.02), mucosal healing (30.8% PRA023 vs 3.5% placebo, Δ27.3%, p<0.0001), and IBDQ response (82.4% PRA023 vs 49.3% placebo, Δ33.1%, p<0.0001; Table 1B). Exposure to prior advanced therapy, antidrug antibody status, and concomitant therapy did not have a major effect on efficacy (Table 1C). Statistically significant reductions in symptom scores were observed as early as week 2 (Figure 1A) and at each visit where C-reactive protein and fecal calprotectin were collected (Figure 1B and 1C). An enhanced treatment effect was observed for the prespecified Dx+ subgroup, with 37.5% for both placebo-adjusted clinical remission and endoscopic improvement. The rates of treatment-emergent adverse events (AEs) were similar between the 2 arms with no serious AEs or AEs leading to study drug discontinuation in the PRA023 arm. There were no safety signals identified from the study.
Conclusions: PRA023 was effective with favorable tolerability for the induction of clinical remission and endoscopic improvement in moderately to severely active UC. A phase 3 study will be conducted to confirm these findings. The enhanced treatment effect in the Dx+ subgroup from cohort 1 is being further evaluated in the Dx+ expansion cohort 2.

Figure 1

Timothy Ritter

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