Subcutaneous Research Articles

P1074 Impact of body mass index (BMI) on clinical outcomes and drug levels in patients with Crohn’s disease receiving maintenance treatment with subcutaneous infliximab: A post hoc analysis of the LIBERTY-CD study

Abstract Background Obesity and high levels of visceral adipose tissue are associated with lower response rates to intravenous (IV) infliximab (IFX).1 Subcutaneous (SC) IFX is a novel formulation that demonstrated superiority to placebo as maintenance therapy in patients (pts) with moderate-to-severe active Crohn’s disease (CD) in the Phase 3 LIBERTY-CD study. Assessing efficacy of SC IFX by BMI is important as, unlike the IV formulation, pts receive a fixed dose. This post hoc analysis aimed to assess the association between BMI and the efficacy of SC IFX therapy. Methods Data from LIBERTY-CD (NCT03945019) were analysed; 231 pts from the SC IFX arm were divided into four subsets by their BMI: underweight (BMI <18.5 kg/m2, n=27); normal (18.5–24.9 kg/m2, n=133); overweight (25–29.9 kg/m2, n=53); obese (≥30 kg/m2, n=18). Co-primary endpoints at Week (W) 54 (clinical remission [CD Activity Index (CDAI) score <150]; endoscopic response [≥50% decrease in Simple Endoscopic Score for CD (SES-CD) from baseline (BL)]) and W54 change from BL in CDAI score were assessed by BMI subset. Correlations between BMI and CDAI score, SES-CD or median trough level of infliximab (TLI), and the impact of BMI on W54 TLI, were evaluated. Analyses were conducted in a descriptive manner. Results At W54, there were no statistically significant differences in co-primary endpoints or change from BL in CDAI score across BMI subsets, despite descending trends in rates of achieving co-primary endpoints, change in CDAI score and TLI with increasing BMI (Table). From the underweight to obese subsets, clinical remission rates were 63.0%, 66.2%, 58.5% and 44.4% (p=0.125), endoscopic response rates were 55.6%, 36.1%, 41.5% and 27.8% (p=0.207) and median changes from BL in CDAI score were −227.3, −212.9, −196.2 and −204.5 (p=0.358). No significant correlations were observed between BMI and CDAI score (Pearson r=0.0972/p=0.141; Spearman rank r=0.0619/p=0.349) or BMI and SES-CD (Pearson r=0.0446/p=0.507; Spearman rank r=0.0375/p=0.577), while there was a weak, but significant, negative correlation between BMI and TLI (Pearson r=−0.2808/p<0.001; Spearman rank r=−0.2829/p<0.001) (Figure). Additionally, there was a significant difference in median W54 TLI across BMI subsets from underweight to obese (17.0, 13.6, 9.3 and 6.6 µg/mL; p=0.007) (Table). Conclusion While there was a significant difference in TLI across BMI subsets, there was no statistically significant impact of BMI on W54 clinical or endoscopic outcomes. These results could be explained by the relatively high TLI achieved with the SC formulation. Further larger and longer-term studies including pts with morbid obesity and utilising body composition assessment are warranted. 1Yarur A et al. Gastroenterology 2023;165:963–75.

P1069 One-year clinical outcomes of switching to subcutaneous infliximab in patients with inflammatory bowel disease on maintenance of intravenous infliximab therapy with or without remission: A multicentre cohort study

Abstract Background An elective switching to the subcutaneous (SC) formulation of infliximab (IFX) has shown effectiveness and safety in patients with inflammatory bowel disease (IBD) on intravenous (IV) IFX maintenance therapy. However, data on long-term outcomes in patients not in clinical remission during maintenance therapy is limited. This study aims to evaluate the long-term outcomes of SC switching in patients who were in clinical remission and not in remission during IV IFX maintenance therapy. Methods This retrospective multicentre study was conducted from January 2021 to October 2023. Clinical remission was defined as Crohn’s Disease Activity Index (CDAI) <150 for Crohn’s disease (CD) and partial Mayo score <2 for ulcerative colitis. Biological remission was defined as faecal calprotectin (FC) <250 µg/g and C-reactive protein (CRP) <0.5 mg/dL. The primary outcome measure was 1-year treatment persistence of SC IFX. Results Among 127 patients included in the study, 80 (62.9%) had CD, and 47 (37.1%) had UC. At the time of switching, 90 patients (70.9 %) were in clinical remission; whereas, 37 (29.1 %) were in a non-remission state. The treatment persistence rate at 1 year was high at 92.9%. Treatment persistence rates between the clinical remission and non-remission groups did not differ significantly (94.4% vs. 89.2%, p=0.287). In both groups, IFX pharmacokinetics and biomarkers between baseline and 12 months (p<0.01) significantly improved. The median infliximab levels increased from a baseline of 3.3 µg/mL (interquartile range [IQR] 1.3–5.1) to 14.4 µg/mL (IQR 9.4–23.0, p<0.001) at 12 months. Disease activity index was stable in the remission group, and decreased in the non-remission group (partial Mayo score, p<0.001; CDAI, p=0.063). At the one-year follow-up, clinical remission and biological remission were achieved in 86.6% and 60.6%, respectively, an increase from baseline (70.9% and 48.0%, respectively). Biologics exposure before IFX was the only significant variable associated with treatment persistence (odds ratio 5.138, 95% confidence interval 1.150–22.951, p=0.032). The concomitant use of immunomodulators was not associated. The incidence of IFX-related adverse events was 14.2%, with only three patients discontinuing treatment. Conclusion Switching to SC IFX from IV IFX maintenance therapy demonstrated high treatment persistence and favourable safety profiles, irrespective of remission status at the time of switching. Patients in both remission or non-remission states showed significant improvement in pharmacokinetics and biomarkers, and/or stable disease activity indices.

P957 Subcutaneous infliximab (CT-P13 SC) for ulcerative colitis: 2-year extension results of the LIBERTY-UC study

Abstract Background Superiority of CT-P13 subcutaneous (SC) infliximab formulation over placebo in maintenance therapy was demonstrated in both ulcerative colitis1 and Crohn’s disease2. LIBERTY-UC study was continued up to Week 102 as an extension phase treatment. We now present the efficacy and safety results up to Week 102 of CT-P13 SC 120 mg group in the LIBERTY-UC study (NCT04205643). Methods Patients who completed the maintenance phase up to Week 54 and, in the opinion of the investigator, would benefit from continued treatment continued the open-label extension phase from Week 56 to Week 102. During extension phase, all patients received CT-P13 SC regardless of previous treatment group randomised at the start of maintenance phase. The patients who had received the adjusted dose of CT-P13 SC 240 mg during the maintenance phase continued receiving CT-P13 240 mg in the extension phase. Patients with dose adjustment to CT-P13 SC 240 mg prior to Week 54 were considered as not to achieve each endpoint. At Week 54 and 102, clinical remission, clinical response, endoscopic-histologic mucosal improvement and corticosteroid-free remission were assessed by among patients who entered and treated in extension phase (Figure 1A), and who entered and treated in extension phase and had valid efficacy results at the visit of interest (Figure 1B). Safety was evaluated throughout the extension phase. Results A total of 237 patients in CT-P13 SC 120 mg group entered into extension phase. Among them, 208 (87%) patients completed extension phase. Proportion of patients who achieved clinical remission, clinical response, endoscopic-histologic mucosal improvement and corticosteroid-free remission at Week 54 and Week 102 among patients who entered and treated in extension phase (i.e., patients who had missing or invalid data were considered as not to achieve each endpoint) are presented in Figure 1A. Among patients who entered and treated in extension phase based on the no imputation for missing or invalid data, each endpoints are generally well maintained or slightly higher in Week 102 compared to Week 54 (Figure 1B). During extension phase, no new safety signals were observed compared to maintenance phase1 (table 1). Conclusion The efficacy of CT-P13 SC 120 mg in UC patients was generally sustained through extension phase. No new safety concerns were found during the extension phase as well. These results indicate that long term use of CT-P13 SC can maintain clinical benefit as well as safety with the convenience of SC administration for patient with moderately to severely active UC. [1] Sands et al., Journal of Crohn's and Colitis, 2023.17(Supplement_1), i623-i624. [2] Colombel et al., Journal of Crohn's and Colitis, 2023.17.Supplement_1: i161-i162

P650 Optimization through iv maintenance with ustekinumab in Inflammatory Bowel Disease. Efficacy and adjusted regimen in real world

Abstract Background Ustekinumab (UST) is an effective treatment for Crohn's disease (CD) and ulcerative colitis (UC). However, some patients do not respond to conventional subcutaneous (SC) doses and lose response at follow-up. The use of maintenance intravenous (IV) UST could play a role in these patients. Methods The aim of the study was to evaluate the effectiveness of IV maintenance UST in patients with failure to subcutaneous UST. Single-center study performed in consecutive patients included in a prospective database. The reduction of activity markers such as C Reactive Protein (CRP) and fecal calprotectin (FC), UST trough levels pre- and post IV maintenance as well as clinical indices of activity were evaluated. IV dose adjustments and their effect on levels were collected. We defined biochemical remission as the percentage decrease FC ≥ 80% and/or final FC ≤ 250. Results Of 335 patients in our center under treatment with ustekinumab, 31 patients (9.25%) were included. Baseline characteristics of patients are shown in Table 1. Mean age at the start of UST IV 42.49 years ± 13.23. CD 77.4%; UC 22.6%. Up to 2/3 of patients with CD had a complicated phenotype (B2/B3) and 50% perianal disease (PD). All included patients were bio-exposed and 61.3% had carried ≥ 2 biologics. The major indication for initiation of UST was secondary failure to previous biologic therapy (74.2%). The most used induction IV dose was 390mg and subsequent SC maintenance was every 8 weeks in 76% (60% were later intensification cases). Re-induction was performed in 36.7% of patients. The median time from drug initiation to IV maintenance was 10.23 [IQR 30.7] months. In 54.8% a higher dose was administered in the first IV maintenance infusion. The most common maintenance regimen was 130mg (64.5%) every 4 weeks (54.8%). Baseline FC decreased significantly (Figure 1) at the end of follow-up (median [IQR]: 809 µg/g [2256] vs 333 µg/g [508], p =0.001). Basal Harvey index was reduced compared to HBI at 24 weeks (mean ± SD: 6.5 ± 4.3 vs 4.1 ± 3.1, p =0.019). Drug levels at the start of IV maintenance were 1.4 µg/ml [IQR 2.3] vs. 4.8 µg/ml [IQR 3.9] at week 24 (p< 0.001) after dose adjustment in 35.5% of patients during IV maintenance. At the end of follow-up 54% went into biochemical remission. The presence of PD was associated with lower biochemical remission (70.6% vs. 27.3%, p =0.025). The median IV UST maintenance time was 8.55 [IQR 23.9] months. 96.6% are continuing treatment. No serious infections or malignancy were documented. Conclusion The use of maintenance IV UST appears to be an effective and safe strategy that can be evaluated as a salvage treatment especially in highly bioexposed patients or with complex CD phenotype.

P625 Electronic patient-reported outcomes in Inflammatory Bowel Diseases on vedolizumab therapy: Interim analysis of the non-interventional German LISTEN II study

Abstract Background Integrating systematic monitoring of patient-reported outcomes (PROs) with clinical information may enhance disease management and improve patient outcomes. Vedolizumab (VDZ) is approved for treating patients with ulcerative colitis (UC) and Crohn’s disease (CD). The German, multicentre, prospective, non-interventional LISTEN II study evaluates patient characteristics and effectiveness of VDZ treatment in real-world clinical practice, focusing on PROs. Methods Adult UC or CD patients, who either initiate VDZ intravenously (IV) or switch from IV maintenance to subcutaneous (SC) formulation, are enrolled. Data on patient characteristics, modalities of VDZ use and disease activity are recorded quarterly over one year. PROs are recorded via weekly questionnaires in app (ePRO). Sustained ePRO use was defined as proportion of patients reporting at least one PRO for ≥80% of available questionnaires. Interim data up to 9 months follow-up are presented. Results Data of 299 UC and 174 CD patients (51% and 59% female, respectively) with a mean age of 40 years were analysed. VDZ treatment was newly initiated IV (start) in 259 UC and 151 CD patients and switched from IV to SC application (switch) by 40 UC and 23 CD patients at baseline. Total mean pMayo score decreased in UC start-patients from 5.0 to 1.7 and from 1.1 to 0.8 in switch-patients. In CD start-patients HBI score decreased from 5.5 to 2.5 and from 3.1 to 2.3 in switch-patients. The ePRO was initially utilized by 226 UC and 124 CD patients (51% and 61% female, 57% and 52% sustained ePRO users, respectively) with a mean age of 39 years; 86% were start- and 14% switch-patients. Disease activity at baseline was comparable to the overall population, showing a total mean pMayo score of 4.5 for UC and a HBI of 5.3 for CD patients. Most UC (82%) and CD patients (88%) used a patient support program for the first time. ePRO use declined to approx. 40% usage within the second quarter and to 30% during further follow-up. Overall, mean symptom scores reported via the ePRO declined during the 9-month follow-up period. The most notable improvements (baseline to month 9) were reported for the symptom impact on work productivity (from 3.9 to 1.7 points) in UC patients and for sick leave (from 1.3 to 0.4 points) in CD patients (Table). For most PROs reduction in symptom scores was apparent within the first week of ePRO-use (Figure). Conclusion LISTEN II real-world data confirm VDZ effectiveness in UC and CD patients, with reduction in disease activity in IV starters and maintained effectiveness in IV-to-SC switchers. Both UC and CD patients reported sustained symptom improvement under VDZ treatment, with scores indicating improvement within the first week of ePRO-use.

P767 Pharmacokinetics of subcutaneous infliximab induction and maintenance in patients with moderate-to-severely active Crohn’s disease

Abstract Background Since 2021, subcutaneous (SC) infliximab (IFX) has been available for maintenance treatment of Crohn’s disease (CD) after an induction phase of 2 intravenous administrations of 5 mg/kg. The DIRECT-CD study is an ongoing randomised multicentre trial in which CD patients receive SC IFX also during induction. The applied SC IFX doses in the DIRECT-CD are based on population pharmacokinetics derived during maintenance treatment with SC IFX. We aimed to validate our induction regimen and correlate serum concentrations with clinical efficacy. Methods Patients with moderate-to-severe CD (Crohn’s disease activity index [CDAI]) >220 and endoscopic ulceration) received fixed SC IFX induction doses of 240 mg at week 0 and 2, followed by maintenance treatment (120 mg every other week). IFX serum concentrations and CDAI were evaluated at week 2, 4, 8, 14 and 26. Clinical remission was defined as a CDAI ≤150. For this analysis, body weight is defined as low if <80 kg and high if ≥80 kg. Results In total, 48 samples of 12 Crohn’s disease patients were analysed (Table 1). During the induction phase (week 2 and 4), observed IFX serum concentrations were lower than expected by the population pharmacokinetic model for all patients (median 15.0 µg/mL [IQR 9.4-20.0]). Moreover, concentrations were significantly lower in patients with a low versus high body weight (median 20.0 µg/mL [IQR 15.0-21.0] vs median 10.2 µg/mL [IQR 4.4-15.8], resp., P=0.004). During the maintenance phase (week 8, 14 and 26), median IFX serum concentrations were also higher in patients with a low body weight compared to patients with a high body weight (17.5 µg/mL [IQR 14.8-19.5] vs 8.9 µg/mL [IQR 5.8-13.8], P<0.001). No patients in the first quartile of IFX serum concentrations (≤7.0 µg/mL) at week 2 reached clinical remission at Week 8, whereas all patients who had an IFX serum concentration at week 2 of ≥15.0 µg/mL reached clinical remission at week 8. At the end of the study (week 26), clinical remission was reached in 67% of patients with a low body weight whereas only 33% of patients with a high body weight reached clinical remission. Conclusion These data implicate the importance of body weight in SC IFX dosing strategies. Based on these findings, SC IFX induction and maintenance treatment is changed to a weight-based dosing scheme in the ongoing DIRECT-CD trial.

P520 Preferences towards treatment attributes among patients with Crohn’s disease and ulcerative colitis in Argentina, Australia, Brazil, Saudi Arabia and Taiwan: a discrete choice experiment

Abstract Background Advanced therapies (ATs) with different mechanisms of action and routes of administration (RoA) are used for inflammatory bowel disease (IBD: Crohn’s disease [CD] and ulcerative colitis [UC]), and patients (pts) play an increasing role in the decision-making process.Pts’ preferences for treatment attributes from 7 European countries have been reported previously; however, evidence from non-European countries is lacking. Methods Adult pts with CD or UC on treatment for ≥6 months from Argentina, Australia, Brazil, Saudi Arabia and Taiwan were enrolled in this cross-sectional, self-administered online survey (Oct 2022 to May 2023). Pts’ preferences for IBD treatment attributes are described. In a discrete choice experiment, the relative importance of treatment attributes was estimated using conditional logit models. Results Overall, 706 pts with CD and UC (n=353 each) completed the survey. Mean (standard deviation [SD]) ages (years [y]) were 36.8 (9.9) and 37.7 (10.2), 47.9% and 47.6% were female, and mean (SD) disease durations (y) were 4.5 (6.0) and 4.6 (6.7) for CD and UC, respectively; 58.1% (CD) and 56.1% (UC) were exposed to ATs. For pts with CD, the rate of long-term remission on maintenance therapy (MT) was the most important attribute for treatment choice (32.5%), followed by the rate of 1-y remission (25.7%), RoA (24.6%) and risk of serious adverse events (AEs, 11.5%) and mild AEs (5.8%). For pts with UC, the rate of corticosteroid-free remission after 1 y was the most important attribute (30.8%), followed by RoA (27.4%), rate of mucosal healing after 1 y (16.1%), long-term remission on MT (14.9%) and risk of serious AEs (10.0%) and mild AEs (0.8%). Country-specific results are shown in the Table. Compared with intravenous administration every 4–8 weeks, pts with CD preferred subcutaneous (SC) administration every 1–2 weeks (odds ratio [95% confidence interval]: 1.41 [1.27–1.56] P<0.001) or every 4–12 weeks (1.22 [1.08–1.39, P=0.002]), and pts with UC preferred taking a tablet (1.41 [1.25–1.59], P<0.001) or SC administration every 4–12 weeks (1.30 [1.14–1.48], P<0.001) or every 1–2 weeks (1.20 [1.07–1.35], P=0.002). Pts exposed to ATs ranked the importance of RoA lower than that of effectiveness compared with AT-naïve pts, and 49.3% of pts with CD and 50.5% with UC indicated that they wanted ATs to start earlier. Conclusion This study highlights the importance of treatment effectiveness, RoA and safety for pts with IBD. Personalised care is crucial given that preferences for treatment attributes may vary across countries and among pts. Patient–physician shared decision-making discussions regarding therapy choice and timing should happen throughout the treatment journey.

P587 Development and Characterization of a Novel Extended Half-life Monoclonal Antibody Drug Candidate Targeting Integrin ɑ4β7 for the Treatment of IBD

Abstract Background Antagonism of the interaction between the cellular adhesion integrin ɑ4β7 and endothelial ligand mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) is a safe and effective mechanism to treat Crohn’s disease (CD) and ulcerative colitis (UC). Additional benefit may be gained from an ɑ4β7 antagonist given via the subcutaneous (SC) route at extended intervals (eg, every 8 to 12 weeks) during maintenance therapy. Methods The novel humanized monoclonal IgG1 antibody SPY001 binds to the same ɑ4β7 epitope as vedolizumab and includes a YTE modification within the Fc region to increase half-life via increased affinity for the neonatal Fc receptor (FcRn), thereby favoring recycling into the circulation over degradation. Binding affinity of SPY001 to ɑ4β7 was determined by kinetic exclusion assay (KinExA) and flow cytometry, and functional activity was determined by inhibition of addressin-mediated cellular adhesion. Results SPY001 binds specifically to ɑ4β7 and not to the related integrins ɑ4β1 and ɑEβ7. In cellular assays, SPY001 binds ɑ4β7 on the surface of RPMI-8866 cells with an affinity matching that of vedolizumab, but it does not bind to Ramos cells expressing ɑ4β1. It demonstrates high affinity for ɑ4β7, with a KD of 836 pM as determined by KinExA. Functionally, SPY001 potently inhibits MAdCAM-1-mediated cellular adhesion with an IC50 comparable to that of vedolizumab but has no inhibitory activity for VCAM-1-mediated cell adhesion. Conclusion SPY001 is a novel humanized monoclonal IgG1 with high affinity for ɑ4β7 and potent inhibition of the ɑ4β7/MAdCAM-1 interaction. It offers the potential for effective and safe treatment of CD and UC with the advantage of infrequent SC dosing. Further preclinical and clinical studies are warranted to demonstrate this potential.

OP14 Effect of mirikizumab on clinical and endoscopic outcomes after 1 anti-TNF failure in patients with moderately to severely active Ulcerative Colitis

Abstract Background Mirikizumab (miri), an anti-IL-23p19 antibody, has demonstrated efficacy and safety in moderately to severely active ulcerative colitis (UC) Phase 3 trials (LUCENT-1 and -2; NCT03518086, NCT03524092) among patients who had an inadequate response, loss of response, or intolerance to conventional or advanced therapy. At the LUCENT-1 induction baseline, 41% of the population had experienced a biologic/tofacitinib failure, and 36.3% experienced at least one anti-TNF failure. Among patients with one prior anti-TNF failure only, this analysis evaluated the clinical efficacy of miri compared to placebo (PBO) in induction and maintenance therapy and the efficacy of miri in extended induction. Methods In LUCENT-1, UC patients were randomized to receive 3 intravenous (IV) doses of 300mg miri or PBO every four weeks (Q4W) at W0, W4, and W8 (induction population). In LUCENT 2, responders to miri induction at W12 were re-randomized to subcutaneous (SC) 200mg miri or PBO Q4W through W52 of continuous therapy (maintenance population). Patients not achieving clinical response with miri 300mg IV at W12 received extended induction treatment with open-label 300mg miri IV at W12, W16, and W20 (extended induction population). Patients responding to extended induction at W24 entered open-label maintenance and received 200mg miri Q4W SC until W52 (extended induction responders). Endpoints evaluated were clinical response, clinical remission, symptomatic remission, endoscopic remission, corticosteroid (CS)-free remission, and histologic-endoscopic mucosal remission (HEMR). Efficacy in the subgroup of patients with failure of one anti-TNF only was assessed using Cochran-Mantel-Haenszel tests at W12 (induction population) and W52 (maintenance population). Results At LUCENT-1 baseline, of patients who experienced anti-TNF failure, 45% of patients (n=190) had one prior anti-TNF failure only (Table 1). In the induction and maintenance populations, a significantly greater proportion of miri-treated patients achieved the following efficacy endpoints compared with PBO [miri vs. PBO, p-value]: clinical response (W12: [64.4% vs. 34.1%, p=0.001]; W52: [67.2% vs. 44.8%, p=0.03]); clinical remission (W52: [44.3% vs. 17.2%, p=0.017]); symptomatic remission (W52: [63.9% vs. 34.5%, p=0.005]) (Table 2). Among the extended induction population, 45.7% achieved clinical response at W24; 75% achieved clinical response, 30% achieved clinical remission and CS-free remission at W52 (Table 2). Conclusion Mirikizumab is efficacious for induction and maintenance therapy in patients with moderately to severely active UC who have failed one prior anti-TNF.

OP12 Mirikizumab improves fatigue, bowel urgency, and quality of life in patients with moderately to severely active Crohn’s Disease: Results from a phase 3 clinical trial

Abstract Background Mirikizumab (miri), an anti-IL-23p19 antibody, is approved for the treatment of ulcerative colitis and under development for Crohn’s disease (CD). We investigated how miri impacted fatigue, bowel urgency, and health-related quality of life (HRQoL) through 52 weeks in patients with moderately to severely active CD in the Phase 3 VIVID-1 study. Methods In the treat-through VIVID-1 (NCT03926130) study, patients (N=1065) with moderately to severely active CD and a Simple Endoscopic Score for CD (SES-CD) score ≥7 (or ≥4 for patients with isolated ileal disease) and failure to biologic and/or conventional therapy were randomized in a 6:3:2 ratio to receive miri (N=579) (a single 900mg intravenous (IV) dose at W0, W4, and W8 followed by a subcutaneous (SC) dose of 300 mg at W12 and then every 4 weeks), ustekinumab (N=287) (6mg/kg IV at W0 and SC dose of 90mg at W8 and then every 8 weeks), or PBO (N=199). At W12 PBO responders continued PBO to W52; PBO-non-responders received the same blinded miri regimen as described above. This analysis focuses on results in patients randomized to either miri or PBO. The change from baseline for Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Urgency Numeric Rating Scale (UNRS), and Inflammatory Bowel Disease Questionnaire (IBDQ) total and domain scores (bowel symptoms, systemic symptoms, emotional function, social function) were analyzed through W52. IBDQ response (≥16-point improvement from baseline) and remission (total score ≥ 170) rates were also analyzed at W12 and W52. For binary variables, adjusted risk differences were compared between miri and PBO using the Cochran-Mantel-Haenszel (CMH) test. For continuous variables, least squares mean changes from baseline were compared between treatment groups using ANCOVA. Results Significant improvement in mean change from baseline to W12 and W52 were observed with miri for FACIT-F, UNRS, and IBDQ total and domain scores (all p<0.000001 at W52) (Figure 1&2). Miri-treated patients showed improved UNRS scores versus PBO as early as W8 with statistical significance sustained to W52 (Figure 1B). At W12 and W52, a greater percentage of miri-treated patients achieved IBDQ response (W12: p<0.000001; W52: p<0.000001) and remission (W12: p<0.000001; W52: p<0.000001) compared to PBO (Figure 2A&B). Conclusion Treatment with miri resulted in improvements in fatigue, bowel urgency, and HRQoL at W12 and W52 in patients with moderately to severely active CD.

P959 Dose escalated vedolizumab in Inflammatory Bowel Disease - Crohn's Colitis Cure (CCC) Data Insights Program

Abstract Background Vedolizumab is a gut specific integrin antagonist with established efficacy in inflammatory bowel disease (IBD). Many people with IBD fail to achieve adequate or sustained response to standard dosing, thus requiring dose escalation (DE). We aimed to explore the need for escalated dosing and subsequent outcomes in a large real-world cohort. Methods We utilised data from the CCC registry entered during routine clinical care at 14 centres across Australia and New Zealand. Data were extracted in October 2023 and included patients on intravenous (IV) and subcutaneous (SC) therapy. DE was defined as maintenance dosing > 108mg SC fortnightly, > 300mg IV Q8weekly and/or additional induction doses. We examined data prior to and at 12 months post DE. Results 919 people with IBD received Vedolizumab, with 28% (n=261) receiving DE therapy. Median age for the DE cohort was 40 years (IQR 29-56) with median age at diagnosis 26 (IQR 19-39). Median age, age at diagnosis, disease duration and BMI did not vary significantly between the DE and standard dosing cohorts. Most of the DE cohort had Crohn’s (60%) followed by ulcerative colitis (38%) and IBD-unclassified (2%). Half the DE cohort was female (49.8%) with median time to dose escalation being 6 months. 57% (n=111) continued on DE Vedolizumab after 12 months. Median drug level (where measured) increased from 10.3mg/L pre-DE to 19.8mg/L post. Rates of faecal calprotectin (FCP) remission, (FCP <250ug/g) increased at 12 months post DE as did rates of PRO2 and endoscopic remission (p=0.007, 0.034 & 0.016 respectively). Improved remission rates coincided with decreased systemic steroid requirements, which fell by >50% at 12 months post DE (p=0.001). Hospital admissions and radiological investigations were unchanged over the study period, however the need for endoscopic assessment decreased 12 months post DE. Patients receiving DE therapy had increased encounters healthcare providers, with more clinical assessment and Healthline calls at 12 months post DE (p=0.001 & 0.001 respectively). Conclusion In an Australasian cohort of people with IBD, over a quarter of individuals receiving Vedolizumab therapy required DE. DE Vedolizumab correlated with improved endoscopic, PRO2 and FCP remission rates at 12 months with reduced steroid use. As biosimilars reduce the cost of DE therapy, further research beyond 12 months examining remission rates, healthcare utilisation and cost analysis in more detail is needed.

P1015 Subcutaneous infliximab effectively manages clinical outcomes of Inflammatory Bowel Disease independently of various confounding factors

Abstract Background Since its approval, many inflammatory bowel disease (IBD) patients have been treated with subcutaneous (SC) infliximab (IFX), but the association of various confounding factors with clinical outcomes is still elusive. Methods The ASSEMBLE project is an initiative to combine multi-national real-world cohort datasets and analyse the effectiveness and safety of SC IFX therapy. In the ASSEMBLE-1 database analysis, three studies from France and the United Kingdom1-3 were integrated to assess the clinical outcomes up to 6 months (6M) after switching from IV to SC IFX. Clinical remission was defined as Harvey-Bradshaw Index (HBI) or modified HBI (mHBI) <5 for Crohn’s disease (CD) and Simple Clinical Colitis Activity Index (SCCAI) or partial Mayo score (PMS) <3 for ulcerative colitis (UC). Treatment persistence was assessed by Kaplan-Meier survival analysis. After adjustment with inverse probability of treatment weights (IPTW), the association of various parameters on clinical outcomes was assessed with marginal structural models (MSMs), by comparing the estimated marginal means (EMMs) of remission rates at 6M between patients in each subgroup. Results The data of 428 patients were pooled from the three datasets (70.6% CD, 29.4% UC). 85.4% of patients were in clinical remission before switching to SC IFX with median HBI or mHBI of 1 (IQR 0,2) for CD and median SCCAI of 2 (IQR 1,3) or PMS of 0 (IQR 0,0) for UC. The overall clinical remission and persistence rates at 6M after switching were 84.7% and 94.5%, respectively. Pre-switch IV IFX regimens, immunomodulator (IMM) use, age, baseline fecal calprotectin (FC) level, or baseline C-reactive protein (CRP) level were not associated with persistence. Persistence rate was >90% regardless of body mass index (BMI), although it was higher for patients <25 kg/m2 BMI (98.1%). Assessment with MSMs indicated that the clinical remission rate of CD, but not UC, was expected to be significantly lower only if patients were treated with escalated IV IFX before switching rather than standard 5 mg/kg Q8W regimen (p=0.01; Table 1). No association with high BMI, IMM use, age, ≥150 μg/g FC, and ≥5 mg/L CRP was found in both CD and UC (Table 1). Perianal disease was not associated with CD remission either. Conclusion The ASSEMBLE-1 results confirm that switching from IV to SC IFX is well accepted and effectively manages the clinical outcomes of the disease regardless of various confounding factors in IBD patients. However, further studies are warranted to explore the association of pre-switch IV IFX regimens with clinical outcomes. [1] Smith et al. J Crohns Colitis 2022 [2] Buisson et al. Clin Gastroenterol Hepatol 2023 [3] Rahmany et al. Gastroenterology 2023.

P712 Effectiveness of switching from intravenous to subcutaneous infliximab in Inflammatory Bowel Disease patients: A combined analysis of real-world evidence

Abstract Background Since approval, numerous inflammatory bowel disease (IBD) patients have been treated with subcutaneous (SC) infliximab (IFX), but real-life data based on a large multi-national population of patients switching from intravenous (IV) to SC IFX is lacking. Methods The ASSEMBLE project is an initiative to combine multi-national real-world cohort datasets and analyse the effectiveness and safety of SC IFX therapy. In the ASSEMBLE-1 analysis, three studies from France and the United Kingdom1-3 were integrated to assess the clinical outcomes up to 6 months (6M) after switching from IV to SC IFX. Clinical remission was defined as Harvey-Bradshaw Index (HBI) or modified HBI (mHBI) <5 for Crohn’s disease (CD) and Simple Clinical Colitis Activity Index (SCCAI) or partial Mayo score (PMS) <3 for ulcerative colitis (UC). Treatment persistence was assessed by Kaplan-Meier survival analysis. Results The data of 428 patients were pooled from the three datasets (70.6% CD, 29.4% UC). 85.4% of patients were in clinical remission before switching with median HBI or mHBI of 1 (IQR 0,2) for CD and median SCCAI of 2 (IQR 1,3) or PMS of 0 (IQR 0,0) for UC. 59.6% of patients were treated with the standard dose of IV IFX (5 mg/kg Q8W) before switching and 54.0% of patients were on concomitant immunomodulator therapy. Patients were switched to SC IFX 120 mg Q2W (94.4%) or 120 mg QW (5.6%) regimen. After switching, the overall clinical remission rates were 83.4% and 84.7% at 3M and 6M, respectively. CD patients were associated with higher remission rate (89.8%) than UC patients (71.9%) at 6M (p<0.001). The disease activity scores and the levels of fecal calprotectin and C-reactive protein of the overall population were maintained stable after switching (Table 1). High persistence was observed in both CD (97.3% at 3M, 94.8% at 6M) and UC patients (96% at 3M, 94.1% at 6M), with no significant difference between indications (p=0.47 at 3M and p=0.78 at 6M). Perianal CD patients (n=89) did not have a significantly worse treatment persistence rate than non-perianal CD patients (p=0.30). The most common reasons leading to drug discontinuation were lost to follow-up, consent withdrawal, worsening of disease activity, and worsening of perianal disease (3 cases for each). Two patients discontinued due to injection-site pain. Conclusion This pooled analysis of ASSEMBLE-1 confirms that switching from IV to SC IFX is effective and safe for CD and UC patients in clinical practice and that the clinical remission is well maintained up to 6M after switching, with no new concerns in safety profiles. [1] Smith et al. J Crohns Colitis 2022 [2] Buisson et al. Clin Gastroenterol Hepatol 2023 [3] Rahmany et al. Gastroenterology 2023.

A detachable dissolving microneedles patch as a new effective platform to deliver Japanese encephalitis live attenuated chimeric vaccine

The purpose of this study was to develop a detachable dissolving microneedles (dDMNs) patch incorporating Japanese encephalitis live attenuated chimeric vaccine (JE-CV) via skin intradermal (ID) immunization. JE-CV-loaded dDMNs (JE-CV:dDMNs at a mass ratio of 1:4) were successfully formulated from NaHCO3:CS:PVA (sodium bicarbonate:chitosan:polyvinyl alcohol) at 0.25:1:4 mass ratio with 121 needles per patch of 1 cm2. The MN patches showed sufficient mechanical strength to resist compression and maintain their appearance after penetrating excised neonatal porcine skin. After application, the MNs arrays were completely detachable from the backing layer at 1 h (∼91 % of delivery efficiency) as wearing time required, and over 80 % of the needles had dissolved after 2 h. For immune responses, the results found that mice immunized with a half-dose of the JE-CV via ID using a JE-CV-loaded dDMNs patch elicited seroprotection (PRNT50 ≥ 10 titers, recommended by the World Health Organization (WHO)) comparable to mice who received a full dose of the JE-CV via subcutaneous (SC) injection. In contrast, mice immunized with a half-dose of the JE-CV via SC injection did not elicit seroprotection. Mice immunized with a half-dose of the JE-CV-loaded dDMNs via ID stimulated IgA higher than mice immunized with the full-dose ∼1.4 times in saliva and nasal wash. For cytokines’ levels, mice immunized with the full-dose of the JE-CV solution via SC induced interferon-gamma (IFN-ɤ) and interleukin-4 (IL-4), the levels were similar to the half-dose of the JE-CV-loaded dDMNs patch ID immunization (p > 0.05). The results revealed that the JE-CV-loaded dDMNs showed promise for effectively stimulating humoral immune responses (HIR) and cell-mediated immune responses (CMIR) to protect against JEV.

A phase 3 randomized study to evaluate safety and immunogenicity of 20-valent pneumococcal conjugate vaccine in healthy Japanese infants

ObjectivesSafety and immunogenicity evaluation of a 4-dose series with 20-valent pneumococcal conjugate vaccine (PCV20). MethodsThis phase 3, double-blind study randomized healthy Japanese infants to receive 4 doses (3 infant doses, 1 toddler dose) of PCV20 by subcutaneous (SC) or intramuscular (IM) injection or 13-valent PCV (PCV13) SC. A primary immunogenicity objective was to demonstrate noninferiority of PCV20 SC to PCV13 SC for percentages of participants meeting predefined serotype-specific immunoglobulin G concentrations 1 month after Dose 3. The 7 additional PCV20 serotypes were compared with the lowest vaccine serotype result in the PCV13 group. Safety and tolerability were assessed as the primary safety objective. ResultsOverall, 668 participants were randomized (PCV20 SC, n = 226; PCV13 SC, n = 224; PCV20 IM, n = 218). The primary noninferiority objective for PCV20 SC to PCV13 SC was met for 11/13 matched and 5/7 additional serotypes. Additional data showed PCV20 SC and IM elicited robust functional opsonophagocytic activity and boosting responses to all 20 vaccine serotypes. PCV20 had a similar safety/tolerability profile to PCV13, although local reactions were less frequent with PCV20 IM. ConclusionsA 4-dose series of PCV20 SC or IM elicited immune responses expected to be protective against all 20 serotypes in Japanese infants. NCT04530838

Retention rate of subcutaneous TNF inhibitors in axial spondyloarthritis in a multicentre study from the RIC-FRANCE network

The objectives of our study were to assess retention rate, safety, and predictive factors for retention of subcutaneous (SC) TNF inhibitors (TNFi) (adalimumab (ADA), etanercept (ETN), golimumab (GOL), and certolizumab pegol (CZP)) in axial spondyloarthritis (axSpA) depending on the line of treatment in real-life conditions. A multicentre retrospective observational study was conducted including 552 patients fulfilling the ASAS criteria for axSpA followed in the RIC-France register who began SC-TNFi between 01/01/13 and 08/31/2018 for a total of 824 prescriptions. Taking all lines of treatment into account, GOL had a significantly higher retention rate compared with ADA, ETN, and CZP with a mean retention length of 59 months. As first-line bDMARDs, GOL had a significantly higher retention rate compared with ADA and ETN. ETN had the best retention rate when prescribed as at least 3rd bDMARD. Taking all lines of treatment into account, female sex, peripheral disease, BASDAI at initiation, and line of treatment were predictive factors for treatment cessation. Primary inefficiency was the most frequent reason for treatment cessation. In conclusion, GOL showed the highest retention rate in axSpA. Male sex, absence of peripheral disease, and early line of prescription were associated with better SC-TNFi retention in axSpA.

Transitioning patients from intravenous to subcutaneous infliximab and vedolizumab for inflammatory bowel disease: what is the opportunity cost of improving access to healthcare?

Biologic drugs are highly effective for inflammatory bowel disease (IBD) management but are key drivers of costs of care especially when administered intravenously (i.v.). Availability of subcutaneous (SC) formulations has increased convenience for patients and improved access to care, but at the cost of revenue to health services. To evaluate the economic impact of transitioning a tertiary centre IBD cohort from i.v. to SC biologic administration and assess the implications for key stakeholders. A retrospective analysis of all patients who received i.v. infliximab or vedolizumab in the outpatient infusion centre of a tertiary IBD centre between July 2019 and June 2021 was undertaken. Data were collated from electronic medical records, pharmacy dispensing systems and the hospital business intelligence unit. An economic analysis and theoretical financial/capacity impact analysis of a transition to an SC model were estimated under two scenarios using a random 10% and 30% of the patient cohort. Transitioning our IBD cohort from i.v. to SC administration would result in a loss to our health service of AU$2 732 123.75, composed of AU$1 463 003.75 in Weighted Inlier Equivalent Separation (WIES) and AU$1 269 120 in drug procurement revenue. However, it would ease capacity in the infusion centre by up to 5256 h. Transitioning patients to SC administration results in improved access to infusion centres and substantial savings to state governments; however, switching results in a loss of i.v. biologic-generated WIES to health services. Alternative funding models are required to achieve sustainability in IBD care and reduce reliance on i.v. biologic-generated income.

Subcutaneous Administration of Monoclonal Antibodies: Pharmacology, Delivery, Immunogenicity, and Learnings From Applications to Clinical Development.

Subcutaneous (s.c.) administration of monoclonal antibodies (mAbs) can reduce treatment burden for patients and healthcare systems compared with intravenous (i.v.) infusion through shorter administration times, made possible by convenient, patient-centric devices. A deeper understanding of clinical pharmacology principles related to efficacy and safety of s.c.-administered mAbs over the past decade has streamlined s.c. product development. This review presents learnings from key constituents of the s.c. mAb development pathway, including pharmacology, administration variables, immunogenicity, and delivery devices. Restricted mAb transportation through the hypodermis explains their incomplete absorption at a relatively slow rate (pharmacokinetic (PK)) and may impact mAb-cellular interactions and/or onset and magnitude of physiological responses (pharmacodynamic). Injection volumes, formulation, rate and site of injection, and needle attributes may affect PKs and the occurrence/severity of adverse events like injection-site reactions or pain, with important consequences for treatment adherence. A review of immunogenicity data for numerous compounds reveals that incidence of anti-drug antibodies (ADAs) is generally comparable across i.v. and s.c. routes, and complementary factors including response magnitude (ADA titer), persistence over time, and neutralizing antibody presence are needed to assess clinical impact. Finally, four case studies showcase how s.c. biologics have been clinically developed: (i) by implementation of i.v./s.c. bridging strategies to streamline PD-1/PD-L1 inhibitor development, (ii) through co-development with i.v. presentations for anti-severe acute respiratory syndrome-coronavirus 2 antibodies to support rapid deployment of both formulations, (iii) as the lead route for bispecific T cell engagers (BTCEs) to mitigate BTCE-mediated cytokine release syndrome, and (iv) for pediatric patients in the case of dupilumab.

DOES INFLAMMATORY AND METABOLOMIC ACTIVITY ON NORMAL AND OSTEOARTHRITIC CHONDROCYTES DIFFER BETWEEN MESENCHYMAL STEM CELLS (MSCS) DERIVED FROM THE INFRAPATELLAR FAT, SYNOVIUM, AND SUBCUTANEOUS TISSUES?

Osteoarthritis (OA) is a disabling disease depriving the quality of life of patients. Mesenchymal stem cells (MSCs) are recently used to modify the inflammatory and degenerative cascade of the disease. Source of MSCs could change the progression and symptoms of OA due to their different metabolomic activities. We asked whether MSCs derived from the infrapatellar fat (IPF), synovium (Sy) and subcutaneous (SC) tissues will decrease inflammatory and degenerative markers of normal and OA chondrocytes and improve regeneration in culture. Tissues were obtained from three male patients undergoing arthroscopic knee surgery due to sports injuries after ethical board approval. TNFa concentration decreased in all MSC groups (Sy=156,6±79, SC=42,1±6 and IPF=35,5±3 pg/ml; p=0,036) on day 14 in culture. On day seven (Sy=87,4±43,7, SC=23±8,9 and IPF=14,7±3,3 pg/ml, p=0,043) and 14 (Sy=29,1±11,2, SC=28,3±18,5 and IPF=20,3±16,2 pg/ml, p=0,043), MMP3 concentration decreased in all groups. COMP concentration changes however were not significant. Plot scores of tissues for PC2-13,4% were significantly different. Based on the results of liquid chromatography-mass spectrometry (LC-MS) metabolomics coupled with recent data processing strategies, clinically relevant seven metabolites (L-fructose, a-tocotrienol, coproporphyrin, nicotinamide, bilirubin, tauro-deoxycholic acid and galactose-sphingosine) were found statistically different (p<0.05 and fold change>1.5) ratios in tissue samples. Focusing on these metabolites as potential therapeutics could enhance MSC therapies.Acknowledgment: Hacettepe University, Scientific Research Projects Coordination Unit (#THD-2020-18692) and Turkish Society of Orthopedics and Traumatology (#TOTBID-89) funded this project. Feza Korkusuz MD is a member of the Turkish Academy of Sciences (TÜBA).

Real-world evidence and patient preference for subcutaneous versus intravenous natalizumab in the treatment of relapsing-remitting multiple sclerosis - initial results from the observational SISTER study.

The consideration of patient preference for a certain drug route of administration (RoA) plays an important role in promoting patient adherence in chronic diseases. Natalizumab is an established treatment for relapsing-remitting multiple sclerosis (RRMS) and can be administered as intravenous (IV) infusion or subcutaneous (SC) injection developed to enable a shorter and easier administration versus IV RoA. Primary objective is to compare patients' preference for RoA and satisfaction with SC versus IV natalizumab at baseline and subsequent visits up to 12 months. Secondary objectives include drug utilization, clinical outcomes, safety, and treatment satisfaction in a usual care setting. SISTER (Subcutaneous: Non-Interventional Study for Tysabri Patient Preference - Experience from Real World) is an ongoing, prospective, observational study where natalizumab is utilized according to local label. RRMS patients are included in three natalizumab cohorts: Patients switching from current IV to SC administration (switcher) and patients newly starting natalizumab on either SC or IV route (starter SC/IV). This interim analysis includes 262 patients (184 switchers, 39 SC starters, and 39 IV starters), median observation period was 9 months. 80.8% IV starters and 93.9% SC starters reported at baseline that they prefer the assigned RoA. Although initial satisfaction with chosen RoA was maintained over time from baseline through Month 12 in all three cohorts, the wish for change of the current RoA after 6 and 12 months was more frequently expressed among IV starters than in either SC cohort. Consistently, six patients (23.1%) starting with IV changed their RoA from IV to SC route.Mean global treatment satisfaction according to TSQM-II score at baseline remained high in the switcher group and increased through Month 12 in both IV and SC starter cohorts. Based on current data, there is a trend toward patients' preference for the natalizumab SC route over the IV route, which provides valuable insights into patients' preference for natalizumab RoA in routine care and complements available data from clinical studies with real-world data on SC natalizumab. This observational (non-interventional) study was registered in the local German PEI register for non-interventional studies (NIS-No. 611) and in the international CTgov register (NCT05304520).