Free Remission Research Articles

A 7-year-boy with Recurrent Acute Disseminated Encephalomyelitis: A Case Report

Acute Disseminated Encephalomyelitis (ADEM) is one form of inflammatory demyelinating disorder of central nervous system affecting the children following an idiopathic course of onset and usually monophasic. Recurrent ADEM is a rare entity and will arise a confusion about its diagnosis. There is no definite clinical criteria and treatment protocol for the management of ADEM. Here we report a case of recurrent ADEM where a 6 year old boy presented with recurrent episodes of low grade fever, difficulty in walking, altered sensorium and focal seizure. MRI of brain showed reappearance of demyelinating lesion on the previous site. The gap between first and second episode was six months. After the first attack of ADEM patient were completely recovered both clinically and neuroradiologically with immunotherapy. But after 7 months of disease free remission, patient again developed same features. So we diagnosed the baby as recurrent ADEM based on the consensus criteria of International Pediatric MS study group (IPMSSG). BANGLADESH J CHILD HEALTH 2023; VOL 47 (1) : 51-54

CML-143 Treatment Free Remission in CML in Lower Resource Setting: A Single-Center Experience

CML-143 Treatment Free Remission in CML in Lower Resource Setting: A Single-Center Experience

The long-term efficacy of eltrombopag in children with immune thrombocytopenia.

Immune thrombocytopenia (ITP) is the most common autoimmune disorder characterized by decreased platelet counts and impaired platelet production. Eltrombopag has been demonstrated to be safe and effective for children with ITP. It is reported eltrombopag can achieve a sustained response off treatment. However, data on its overall efficacy and safety profile are scarce in children. This study aimed to investigate the long-term efficacy of eltrombopag in children with ITP. Treatment overall response (OR), complete response (CR), response (R), durable response (DR), no response (NR), treatment free remission (TFR), and relapse rate, were assessed in 103 children with ITP during eltrombopag therapy. The OR rate, CR rate, R rate, DR rate, NR rate, TFR rate, and relapse rate were 67.0%, 55.3%, 11.7%, 56.3%, 33.0%, 60%, 36.2%, respectively. Importantly, we discovered that newly diagnosed ITP patients showed a higher DR rate, TFR rate and lower relapse rate compared to persistent and chronic ITP patients. Furthermore, the CR rate, DR rate, and TFR rate of 5 patients under six months were 100%. None of them suffered relapse. The most common adverse event (AEs) was hepatotoxicity (7.77%). Our study highlighted the critical role of eltrombopag as the second-line treatment in children with ITP who were intolerant to first-line therapy.

Discontinuation of Tyrosine Kinase Inhibitor Therapy and Treatment Free Remission (TFR) in Chronic Myeloid Leukemia: Successful Achievement of TFR in More Than Two-Third of Patients in a Real-World Practice

BackgroundDiscontinuation of TKI therapy and treatment-free remission (TFR) have become new goals for chronic-phase chronic myeloid leukemia (CP-CML). The aim of this study was to estimate the TFR post discontinuation of TKI therapy at 3 tertiary-care centers. Patients and MethodsCP-CML patients aged ≥16 years who had an attempt to discontinue TKI therapy till June 2022, were eligible. The collected data included patients’ demographics, prognostic score, type and duration of TKI therapy, response dates, relapse dates, response to re-initiation of TKI therapy, and risk factors for relapse. ResultsFifty-five patients (35, 63.6% females) with a median age of 40 (range 16-74) years at diagnosis discontinued therapy. Forty-eight (87.3%) patients received imatinib as first line therapy. Twenty-nine (52.7%) patients were receiving imatinib at the time of TKI-discontinuation. Median time from diagnosis to TKI discontinuation was 86 months (IQR 60;132) and median duration of TKI therapy after achieving DMR was 66 months (IQR 47;114). After a median follow up of 34 (IQR 12;68) months, 15 (27.3%) patients relapsed. Median time to relapse was 5 months (range 2-38). Most of the relapses occurred during the first 6 months except 3 (20%) patients. All the relapsed patients achieved MMR after a median of 3 (range 2-6) months after restarting TKI therapy. None of the patients progressed to advanced-phase. ConclusionOur experience confirms that discontinuation of TKI therapy in CP-CML patients is feasible and safe in routine clinical practice, and can achieve TFR in more than two-third of carefully selected patients.

#2748 Combined rituximab and daratumumab treatment in difficult to treat nephrotic syndrome cases

Abstract Background and Aims Common treatments for multidrug-resistant and multidrug-dependent nephrotic syndrome (NS) are inconsistently effective and burdened by long-term toxicities. Moreover, affected patients are at high risk of progression to end-stage kidney failure. Objective To test the safety/efficacy profile of combined single infusion of rituximab and daratumumab in inducing proteinuria remission in multidrug resistant nephrotic syndrome and maintaining drug free disease remission in patients with multidrug-dependent nephrotic syndrome after removal of oral immunosuppression. Method We here present a Phase 2 Proof-of-Concept single-arm clinical trial, that enrolled consecutive participants at the Nephrology Unit of the IRCCS Giannina Gaslini Children's Hospital in Genoa, Italy, between September 2021 and March 2023. Enrolled patients, aged between 3 and 24 years, were multidrug-dependent or multidrug-resistant nephrotic syndrome for at least 12 months before enrolment. Multidrug-dependency was defined by the need of at least 2 oral immunosuppressive drugs (prednisone and/or calcineurin inhibitors and/or mycophenolate mofetil) and by the occurrence of at least two consecutive relapses on two immunosuppressive drugs. Multidrug-resistance nephrotic syndrome was defined by the lack of antiproteinuric effect of a double immunosuppressive therapy. Exclusion criteria included genetic forms of NS and administration of monoclonal therapies in the last 9 months before enrolment. Interventions: Rituximab and daratumumab were administered as single doses at 375 mg/m2 and 16 mg/kg, respectively, 15 days apart. Main Outcomes and Measures:Proteinuria, serum albumin, Immunoglobulin M and G, B and T lymphocyte subsets, safety, Quality of Life. Results A total of 7 consecutive multidrug-resistant and 16 multidrug-dependent NS, respectively, were enrolled. In multidrug-resistant NS, combined rituximab and daratumumab promoted complete or partial remission in 6 patients (Fig. 1A). Five subjects experienced proteinuria relapse, that was effectively treated with a second course of combined treatment. Decreased of I'm, but not IgG, correlated with improvement of proteinuria (Fig. 1B).These treatment allowed to reduce the chronic immunosuppressive treatment daily administered (Fig. 1C). In multidrug-dependent NS, combined rituximab and daratumumab extended the relapse-free time, allowing us to remove oral immunosuppressant (Fig. 1D). Disease relapse was invariably anticipated by a recovery of circulating IgM:patients with IgM levels below median values measured at 3 mo post-treatment had a significantly lower rate of relapse at 9 mo than patients with higher IgM levels at 3 mo (Fig. 1E). Combined treatment induced significative reduction of CD38+ plasma cells (Fig. 1F) and IgM, but not IgG. Treatment was well tolerated and significantly increased quality of life. Conclusion Combined rituximab and daratumumab was safe and effective in the treatment of complicated forms of NS, offering a new therapeutic option for this severe condition.

Real World Outcomes with Treatment Free Remission in Chronic Myeloid Leukemia-Experience from a Tertiary Care Cancer Centre.

Chronic myeloid leukaemia (CML) is caused by balanced translocation t(9::22)(q34;q11) resulting in formation of pathogenic BCR-ABL fusion gene. Tyrosine kinase inhibitors (TKI) have revolutionised the treatment of CML. Ongoing treatment with TKI leads to side effects and has financial impact. Teratogenic potential of TKI and growth disturbance also represent an important challenge. Thus, TKI discontinuation in form of treatment free remission (TFR) has emerged as a new and important therapeutic goal. In this retrospective study, we reviewed CML patients who were kept on TFR. Inclusion criteria was patient age ≥ 18years diagnosed with CML in chronic phase who met the criteria for TFR and opted for same and who were in DMR but stopped TKI for any reason. We analysed the data for baseline characteristics, molecular relapse (MR), survival without molecular relapse (SWMR), TFR duration and factors affecting MR. We included 38 patients in this analysis. Thirty five (92%) patients were treated with imatinib at diagnosis. Median duration of TKI treatment was 135months. 37 patients (97.5%) achieved DMR on TKI and median time from TKI initiation to DMR was 96months. Median duration of DMR prior to TKI discontinuation was 41months. TKI was discontinued after counselling for TFR in 26 patients (68%) while it was discontinued due to intolerance in 10 patients (29%). At median molecular follow up of 25months, nine patients (23.7%) had molecular relapse. Median SWMR was not reached and 2year estimated SWMR was 65.2% (95%CI,47.2- 83.2). Of all relapses, 5/9 (55.5%) occurred in the first six months of TFR. On univariate analysis, duration of TKI and duration of DMR were predictive of molecular relapse. On multivariate analysis, none of these factors were found to be significant. This retrospective study suggests that for CML CP patients achieving deep molecular response, discontinuing TKI therapy in real-world settings may be feasible while potentially achieving comparable outcomes.

Resolution of rectal bleeding by day 7 in acute severe ulcerative colitis is prognostic for post-discharge corticosteroid free clinical remission and endoscopic improvement.

This study assesses two different disease activity measures, the MTWSI and the partial Mayo score, in hospitalized acute severe UC patients for prediction of post-discharge corticosteroid-free clinical remission and endoscopic improvement to help guide future considerations for disease activity assessment. In this post-hoc analysis from the TRIUMPH trial, these results suggest resolution of Mayo rectal bleeding sub-score may have high prognostic utility and could be considered as a primary endpoint for hospitalized UC trials. The study underscores the need for further research on patient-reported outcomes and endoscopic indices in larger populations for inpatient UC trials.

A 7-year-boy with Recurrent Acute Disseminated Encephalomyelitis: A case report.

Acute Disseminated Encephalomyelitis (ADEM) is one form of inflammatory demyelinating disorder of central nervous system affecting the children following an idiopathic course of onset and usually monophasic. Recurrent ADEM is a rare entity and will arise a confusion about its diagnosis. There is no definite clinical criteria and treatment protocol for the management of ADEM. Here we report a case of recurrent ADEM where a 6 year old boy presented with recurrent episodes of low grade fever, difficulty in walking, altered sensorium and focal seizure. MRI of brain showed reappearance of demyelinating lesion on the previous site. The gap between first and second episode was six months. After the first attack of ADEM patient was completely recovered both clinically and neuroradiologically with immunotherapy. But after 7 months of disease free remission, patient again developed same features. So we diagnosed the baby as recurrent ADEM based on the consensus criteria of International Pediatric MS study group (IPMSSG). BANGLADESH J CHILD HEALTH 2022; VOL 46 (3) : 144-147

STEP-CD study: ustekinumab use in paediatric Crohn's disease-a multicentre retrospective study from paediatric IBD Porto group of ESPGHAN.

Ustekinumab is an effective therapy for adult Crohn's disease (CD), but data in paediatric CD patients are scarce. The aim of the study was to describe the real-life effectiveness and safety of ustekinumab in paediatric CD. This is a multicentre review of children with Crohn's disease treated with ustekinumab. The aim of our study was to describe the effectiveness and safety of ustekinumab in paediatric real-life practice. This is a study of the Paediatric IBD (inflammatory bowel disease) Porto group of ESPGHAN. Corticosteroid (CS)- and exclusive enteral nutrition (EEN)-free remission, defined as weighted Paediatric Crohn's Disease Activity Index (wPCDAI) < 12.5, and physician global assessment (PGA) were determined at weeks 12 and 52. A total of 101 children were included at a median age of 15.4 years (IQR 12.7-17.2) with a median follow-up of 7.4 months (IQR 5.6-11.8). Ninety-nine percent had received prior anti-TNF, 63% ≥ 2 anti-TNFα therapies and 22% vedolizumab. Baseline median wPCDAI was 39 (IQR 25-57.5) (71 (70%) patients with moderate-severe activity). Weeks 12 and 52 CS- and EEN-free remission were both 40.5%. Clinical response at week 6, iv induction route and older age at onset of ustekinumab treatment were predictive factors associated with clinical remission at week 12. Seven minor adverse events probably related to ustekinumab were reported. One patient died from an unrelated cause. Conclusion: Our results suggest that ustekinumab is effective and safe in children with chronically active or refractory CD. What is Known: • Ustekinumab is an effective therapy for adult moderate to severe Crohn's disease (CD). • Off-label use of ustekinumab in children is increasing especially in anti-TNF refractory CD. What is New: • Is the largest cohort of real-world use of ustekinumab in paediatric CD to date. • Clinical response at week 6, iv induction and older age at onset of ustekinumab were predictive factors associated with clinical response at week 12.

Recent advances on anti-HIV chimeric antigen receptor-T-cell treatment to provide sustained HIV remission.

Successful sustained remission of HIV infection has been achieved after CCR5Δ32/Δ32 allogeneic hematopoietic stem cell transplantation for treatment of leukemia in a small cohort of people living with HIV (PLWH). This breakthrough demonstrated that the goal of curing HIV was achievable. However, the high morbidity and mortality associated with bone marrow transplantation limits the routine application of this approach and provides a strong rationale for pursuing alternative strategies for sustained long-term antiretroviral therapy (ART)-free HIV remission. Notably, long-term immune-mediated control of HIV replication observed in elite controllers and posttreatment controllers suggests that potent HIV-specific immune responses could provide sustained ART-free remission in PLWH. The capacity of chimeric antigen receptor (CAR)-T cells engineered to target malignant cells to induce remission and cure in cancer patients made this an attractive approach to provide PLWH with a potent HIV-specific immune response. Here, we review the recent advances in the design and application of anti-HIV CAR-T-cell therapy to provide a functional HIV cure. HIV reservoirs are established days after infection and persist through clonal expansion of infected cells. The continuous interaction between latently infected cells and the immune system shapes the landscape of HIV latency and likely contributes to ART-free viral control in elite controllers. CAR-T cells can exhibit superior antiviral activity as compared with native HIV-specific T cells, particularly because they can be engineered to have multiple HIV specificities, resistance to HIV infection, dual costimulatory signaling, immune checkpoint inhibitors, stem cell derivation, CMV TCR coexpression, and tissue homing ligands. These modifications can significantly improve the capacities of anti-HIV CAR-T cells to prevent viral escape, resist HIV infection, and enhance cytotoxicity, persistence, and tissue penetration. Collectively, these novel modifications of anti-HIV CAR-T cell design have increased their capacity to control HIV infection. Anti-HIV CAR-T cells can be engineered to provide potent and sustained in-vitro and in-vivo antiviral function. The combination of anti-HIV CAR-T cells with other immunotherapeutics may contribute to long-term HIV remission in PLWH.

Gaining momentum: stem cell therapies for HIV cure.

Durable HIV-1 remission has been reported in a person who received allogeneic stem cell transplants (SCTs) involving CCR5 Δ32/Δ32 donor cells. Much of the reduction in HIV-1 burden following allogeneic SCT with or without donor cells inherently resistant to HIV-1 infection is likely due to cytotoxic graft-versus-host effects on residual recipient immune cells. Nonetheless, there has been growing momentum to develop and implement stem cell therapies that lead to durable long-term antiretroviral therapy (ART)-free remission without the need for SCT. Most current research leverages gene editing techniques to modify hematopoietic stem cells which differentiate into immune cells capable of harboring HIV-1. Approaches include targeting genes that encode HIV-1 co-receptors using Zinc Finger Nucleases (ZFN) or CRISPR-Cas-9 to render a pool of adult or progenitor cells resistant to de-novo infection. Other strategies involve harnessing multipotent mesenchymal stromal cells to foster immune environments that can more efficiently recognize and target HIV-1 while promoting tissue homeostasis. Many of these strategies are currently in a state of infancy or adolescence; nonetheless, promising preclinical and first-in-human studies have been performed, providing further rationale to focus resources on stem cell therapies.

Abstract 187: Macrophage instead of leukemia cell expressed PD-L1 drives T cell exhaustion and immune evasion of BCRABL1 chronic myeloid leukemia

Abstract BCR-ABL1 fusion gene is the hall marker of chronic myeloid leukemia (CML). Currently, the immune microenvironment of BCRABL1 CML remains largely unexplored. Our recent investigation in a transgenic mouse model of BCRABL1 CML revealed a continuous increase in CD11b+Ly6Cint PMN-MDSC with the progression of the disease. Concurrently, there was an increase in CD11b+Ly6Chigh M-MDSC and F4/80+ macrophages. However, The levels of CD4+ T cells, CD8+ T cells, CD19+ B cells, and CD49b+ NK cells, which are essential for tumor-killing significantly decreased. This immune phenotype was consistently observed in both primary leukemia induction and following serial transplantation of cells from primary leukemic mice. Intriguingly, only recipient mice subjected to sublethal irradiation developed the disease, while mice with intact immune system remained disease-free, which underscores the vital role of the immune system in the development of CML. The predominant presence of CD11b+Ly6Cint PMN-MDSC in the peripheral blood, bone marrow and spleen implies these cells may be at least partially consisted of CML leukemia cells. To examine the hypothesis, qRT-PCR and immunofluorescence (IF) staining were conducted. In both assays, Ly6G+ cells from BCRABL1 mice coexpressed the BCRABL1 oncogene. Furthermore, when co-cultured with CD4 T cells, the division of T cells was significantly inhibited, implying immune suppression by the Ly6G+ PMN-MDSCs and/or CML leukemia cells. In addition, the immuosuppressive pathway genes including Arg1, Hif1a, Enptd1, TGFβ were significantly upregulated. To investigate the possible role of the PD1/PDL1 axis in the BCRABL1 model, flow cytometry analysis was conducted. Unexpectedly, PDL1 was barely expressed in CML leukemia cells, whereas the expression of PDL1 in M-MDSCs and macrophages significantly increased, accompanied by remarkable upregulation of PD1 expression on CD4 T cells and CD8 T cells during leukemia progression. In other words, PDL1 expression on macrophages, rather than leukemia cells, was found to induce T cell exhaustion. For translational purpose, mice transplanted with the primary CML leukemia cells were treated with chemotherapy drugs ponatinib alone or in combination with the anti-PD1 antibody. Compared with the chemotherapy alone group, the mice in the combinational therapy group exhibited rapid remission and better disease control. Most importantly, the disease relapse occurred at a slower rate after treatment discontinuation, suggesting the value of combinational therapy in achieving treatment free remission. In summary, our study not only revealed the dynamic changes of immune microenvironment in the BCRABL1 CML mouse model, but also revealed the different mechanisms underlying immune evasion of BCR-ABL1 CML leukemia cells, which sheds light on a combinational treatment for achieving the treatment free remission of CML. Citation Format: Xiaocui Lu, Hui Fang, Xuexiu Fang, Atsuko Matsunaga, Kebin Liu, Jorge Cortes, John K. Cowell, Tianxiang Hu. Macrophage instead of leukemia cell expressed PD-L1 drives T cell exhaustion and immune evasion of BCRABL1 chronic myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 187.

Outcomes of polymyalgia rheumatica in real-world practice: a longitudinal cohort study.

Background: Polymyalgia rheumatica (PMR) is an inflammatory condition closely linked with giant cell arteritis, which is a large vessel vasculitis. To provide real-world evidence on PMR outcomes and their determinants, we conducted a longitudinal study focusing on symptom relief and acute phase reactant normalization. Methods: We followed patients with PMR who were registered in Tabriz University of Medical Sciences Vasculitis Registry (TUOMS-VR) until February 2023. We measured sustained remission (primary outcome) and secondary outcomes including glucocorticoids (GCs)-free remission, medication-free remission, relapse rate and disease-induced damage. Results: We identified eighty-one patients with PMR and followed them for a median time of 57 months. In a median duration of 3 weeks, 98.8% of patients achieved symptom control, with 86.4% achieving sustained remission in a median duration of 9 weeks. Sustained remission was more common in non-smokers and adherent to therapy patients. Relapse occurred in 22.1% of patients, primarily due to non-adherence. Medication-free remission was observed in 30.9% of patients, especially among females and those with an initial prednisolone dose > 15 mg/d. Damage occurred in 42.0% of patients. Conclusion: Although sustained remission in PMR is not an unattainable goal in daily practice and most patients are in remission at the last visit, two-thirds of patients require long-term treatment.

A comparison of Bayesian and frequentist approaches to incorporating clinical and biological information for the prediction of response to standardized pediatric colitis therapy.

The prospective cohort study PROTECT is the largest study in pediatric ulcerative colitis (UC) with standardized treatments, providing valuable data for predicting clinical outcomes. PROTECT and previous studies have identified characteristics associated with clinical outcomes. In this study, we aimed to compare predictive modeling between Bayesian analysis including machine learning and frequentist analysis. The key outcomes for this analysis were week 4, 12 and 52 corticosteroid (CS)-free remission following standardized treatment from diagnosis. We developed predictive modeling with multivariable Bayesian logistic regression (BLR), Bayesian additive regression trees (BART) and frequentist logistic regression (FLR). The effect estimate of each risk factor was estimated and compared between the BLR and FLR models. The predictive performance of the models was assessed including area under curve (AUC) of the receiver operating characteristic (ROC) curve. Ten-fold cross-validation was performed for internal validation of the models. The estimation contained 95% credible (or confidence) interval (CI). The statistically significant associations between the risk factors and early or late outcomes were consistent between all BLR and FLR models. The model performance was similar while BLR and BART models had narrower credible intervals of AUCs. To predict week 4 CS-free remission, the BLR model had AUC of 0.69 (95% CI 0.67-0.70), the BART model had AUC of 0.70 (0.67-0.72), and the FLR had AUC of 0.70 (0.65-0.76). To predict week 12 CS-free remission, the BLR model had AUC of 0.78 (0.77-0.79), the BART model had AUC of 0.78 (0.77-0.79), and the FLR model had AUC of 0.79 (0.74-0.83). To predict week 52 CS-free remission, the BLR model had AUC of 0.69 (0.68-0.70), the BART model had AUC of 0.69 (0.67-0.70), and the FLR model had AUC of 0.69 (0.64-0.74). The BART model identified nonlinear associations. BLR and BART models had intuitive interpretation on interval estimation, better precision in estimating the AUC and can be alternatives for predicting clinical outcomes in pediatric patients with UC. BART model can estimate nonlinear nonparametric association.

Treatment Free Remission in CML

Treatment Free Remission in CML

REAL-WORLD SAFETY AND EFFICACY OF USTEKINUMAB AND VEDOLIZUMAB IN PEDIATRIC PATIENTS WITH INFLAMMATORY BOWEL DISEASE

Abstract CONTEXT/PURPOSE Ustekinumab and vedolizumab are approved biologicals to treat adults with inflammatory bowel disease (IBD) but currently administered off-label for children. Aims: (1) assess safety and adverse events during treatment with ustekinumab or vedolizumab in pediatric IBD and (2) assess steroid free clinical remission and mucosal healing at 6 months and 1 year. METHODS Retrospective chart review of pediatric patients (&amp;lt;22 years) with IBD treated at an academic hospital and two affiliated practices. Inclusion: Patients with IBD who received either ustekinumab or vedolizumab between January 2015 to June 2022 with minimum of 6 months follow up. Clinical remission assessed by Pediatric Ulcerative Colitis Activity Index (PUCAI) &amp;lt; 10 and short Pediatric Crohn’s Disease Activity Index (shPCDAI) &amp;lt;15, and mucosal healing by fecal calprotectin &amp;lt;250 mcg/gram. RESULTS Fifty-eight patients received vedolizumab and 55 patients received ustekinumab. Patients with ulcerative colitis (UC) or IBD unclassified (IBDU) on vedolizumab were more likely to be in remission at 6 months (58% vs. 42%, p = 0.3, Table 1) and significantly higher at achieving 1-year steroid free remission (64% vs. 27%, p = 0.019) compared to ustekinumab. Over two thirds of biologic naïve and about half of biologic exposed patients who received vedolizumab achieved 1-year steroid free remission (78% vs. 58%, Figure 1). All patients who received ustekinumab were biologic exposed. In Crohn’s disease (CD), no significant difference was seen in children receiving vedolizumab compared to ustekinumab at 6 months remission (57% vs. 63%, p = 0.7) or 1-year steroid free remission (70% vs. 70%, p &amp;gt;0.9). All biologic naïve patients and half of biologic exposed patients who received vedolizumab achieved 1 year steroid free remission. Both bionaive and two thirds of biologic exposed patients who received ustekinumab achieved 1-year steroid free remission (100% vs. 67%). When comparing vedolizumab and ustekinumab, no significant difference was observed in 6 month remission (73% vs. 59%, p = 0.2) and 1-year steroid free remission based on calprotectin (61% vs. 66%, p = 0.7). Similar to clinical remission rates, biologic naïve patients tended to have higher remission rates based on calprotectin. Five patients each had minor adverse events with ustekinumab and vedolizumab, and 20 were hospitalized mostly for IBD flare. CONCLUSION Both biologicals were safe and effective in achieving clinical remission at 6 months and 1 year. They were more effective when used in bionaive patients, although numbers were very low for ustekinumab. The superior efficacy of vedolizumab in UC and IBDU at 1-year may be attributed to larger cohort of bionaive patients. Larger multicenter prospective studies are needed to validate these findings regarding efficacy and safety of vedolizumab and ustekinumab in pediatric IBD. Table 1 Remission on Vedolizumab and Ustekinumab Figure 1 Remission on Vedolizumab vs. Ustekinumab Stratified by Biologic Exposure

INFLIXIMAB AND VEDOLIZUMAB HAVE SIMILAR CLINICAL AND SAFETY OUTCOMES AMONG BIOLOGIC-NAÏVE PATIENTS WITH MILD TO MODERATE PEDIATRIC INFLAMMATORY BOWEL DISEASE

Abstract BACKGROUND Infliximab (IFX) is the only FDA-approved intravenous therapy for the treatment of pediatric inflammatory bowel disease (IBD). The gut-selective anti-integrin vedolizumab (VDZ) has been increasingly used as second-line therapy. However, the comparative effectiveness of IFX vs. VDZ to treat biologic-naïve children with IBD is currently unknown. AIMS 1. Compare the real-world effectiveness of IFX vs. VDZ in bio-naïve pediatric patients with IBD at 12 months. 2. Study the safety of IFX and VDZ in the pediatric population. METHODS A single-center retrospective cohort study was conducted at an academic children’s hospital between February 2015 and August 2023. We included bio-naive mild-moderate IBD patients, &amp;lt;23 years old, who started IFX or VDZ as their first advanced therapy. Patients with a confirmed diagnosis of IBD based on Porto criteria with baseline and at least 6-month follow-up data were included. Exclusion criteria were designed to limit the study population to patients who would typically be eligible for vedolizumab treatment according to the current standard of care, including: prior biologic use; steroid-refractory acute-severe colitis; stricturing or penetrating Crohn’s disease (CD); or perianal disease; and extraintestinal manifestations. The primary outcome was steroid-free clinical remission (SFCR) at 12 months, defined by the PUCAI &amp;lt;10 or ShPCDAI &amp;lt;10 and off corticosteroids. Biochemical remission (BR) was defined as fecal calprotectin (FCP) &amp;lt;250 μg/g. Descriptive statistics included the Chi-square and the Mann-Whitney U test. RESULTS Among the 100 included patients, 73 in IFX group vs. 27 in VDZ group, the mean age was 13 ± 4 years old, males were 68% (IFX) vs. 41% (VDZ) (P = 0.01). 49% had CD, 48% had UC, and 3% had unclassified IBD (IBDU). IFX- and VDZ-treated patients had similar Paris classifications. Baseline albumin levels (3.7 vs. 4.2 g/L, P&amp;lt;0.01) and steroid use (58% vs. 74%, P = 0.13) were lower in IFX vs. VDZ-treated patients. 12-month SFCR was 72% (49/68) and 71% (15/21) in IFX- and VDZ-treated patients, respectively (NS). Among SFCR at 12 months, BR was 59.62% (IFX) vs. 76.47% (VDZ), P = 0.21. Adverse events were rated as mild to moderate and occurred rarely in 8.22% (6/73) of IFX patients and in 7.41% (2/27) of VDZ patients (P = 0.89). These included an infusion reaction (1 in each group), elevated liver enzymes (1 in each group), infection (1), folliculitis (1), eczema (1), , and psoriasis (1). CONCLUSION We found both IFX and VDZ to have similar effectiveness in achieving SFCR and BR at 12 months when used as first-line agents for patients with uncomplicated mild-moderately active IBD. Prospective, larger head-to-head studies are needed for further validation. IFX group vs. VDZ group at the baseline. IFX group vs. VDZ group for Steroid Free Clinical Remission Patients at 12 months.

SYSTEMATIC REVIEW WITH META-ANALYSIS: SAFETY AND EFFICTIVENESS OF COMBINING BIOLOGICS AND SMALL MOLECULES IN INFLMAMMATORY BOWEL DISEASE

Abstract BACKGROUND Effectiveness and safety of Dual biologic therapy (DBT) or in combination with small molecules for treatment of refractory cases of inflammatory bowel diseases (IBD) has been studied previously. In this systematic review and meta-analysis (SRMA), our aim was to update prior SRMA by Alayo et al including newer studies and randomized clinical trials Explorer and VEGA and newer endpoints including corticosteroid free remission rates, need for surgeries, and effectiveness based on IBD subtype. METHODS We conducted a systematic literature search using Clinical trials.gov, Cochrane Library, Embase, Ovid Medline, PubMed Medline, Scopus and Web of Science, identifying additional relevant studies published until January 19, 2023. Random-effects inverse variance model was used to combine the proportions of patients who achieved response/remission or developed AEs to obtain pooled estimates (primary outcomes). RESULTS A total of 1184 citations were identified through the database searches, of which 360 duplicates and 755 unsuitable studies were excluded following title/abstract screening. Then, the full-texts of the remaining 69 articles were retrieved for further investigation. Of these, 59 were excluded, leaving 10 additional eligible studies since the prior systematic review. A total of 23 studies met the inclusion criteria including 13 in prior SRMA, published between 2007 and 2023. Final analysis included 531 patients who underwent 543 therapeutic trials (TTs) of 8 different combination therapies. Of these 264 (49.7%) were men men. Among combination therapies, Ustekinumab (UST) + anti-tumor necrosis factor-alpha antagonist (aTNF) had the highest pooled clinical response (81.6% [95% CI: 66.2-97.0], I2=52%, p=0.04; 9 studies, 44 TTs) and remission (Figure 1) (64.2% [95% CI: 45.2-83.1], I2=55%, p=0.03; 8 studies, 42 TTs) rates. In patients with CD, the highest pooled clinical response and remission rates pertained to UST + aTNF (91.6% [95% CI: 79.8-100.0], I2 = 19%, p=0.28; 8 studies, 29 TTs). In patients with UC, the highest pooled clinical response rate was seen with Vedolizumab (VDZ)+UST (100.0% [95% CI: 70.0-100.0], I2 = 0%, p=1.00; 4 studies, 4 TTs) and UST + aTNF (100.0% [95% CI: 73.2-100.0], I2 = 0%, p =1.00; 4 studies, 5 TTs). and while the highest pooled clinical remission rate was with VDZ + UST (75.0% [95% CI: 26.0-100.0], I2 = 63%, p=0.05; 4 studies, 4 TTs). The lowest pooled AEs rate (Figure 2) related to tofacitinib (Tofa) + VDZ (12.5% [95% CI: 2.9-22.0], I2 = 41%, p = 0.10; 8 studies, 76 TTs), followed by UST + aTNF (12.7% [95% CI: 0.0-25.8], I2=43%, p = 0.08; 9 studies, 43 TTs) and Tofa+aTNF (13.0% [95% CI: 0.8-25.3], I2=49%, p=0.08; 6 studies, 27 TTs) in patients with IBD. CONCLUSION Combining biologics or with small molecules in treatment of refractory IBD is promising and appeared to be generally safe with no major side effects. Figure 1 Clinical remission Figure 2 Adverse events

P964 Vedolizumab trough concentrations during subcutaneous treatment in patients with inflammatory bowel diseases

Abstract Background An exposure-response relationship has been described for intravenous (IV) vedolizumab (VDZ), but little is known about through levels and real life outcomes of subcutaneous (SC) VDZ treatment. We aimed to study the effect of SC VDZ in a prospective real life cohort and assessed what clinical variables are associated with vedolizumab trough concentrations. Methods IBD patients initiating VDZ SC treatment were included in our nationwide, prospective Initiative on Crohn and Colitis (ICC) registry. Adult IBD patients were included if a known trough level during IV and SC therapy was available. Two different assays were used for trough levels measurements : i.e. an enzyme linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The primary outcome measure was the mean VDZ trough concentration during maintenance treatment (after at least four SC injections). In addition, associations between VDZ serum trough concentrations and corticosteroid-free clinical remission were assessed. A Receiver Operating Characteristic (ROC) analysis was performed to determine the concentration threshold that was associated with corticosteroid free clinical remission after 4 SC VDZ injections (i.e. defined as a Harvey Bradshaw Index (HBI) score ≤ 4 for CD and a Short Clinical Colitis Activity Index (SCCAI) score ≤ 2 for UC). Results In total, 24 with Crohn’s disease (CD) and 32 with ulcerative colitis (UC) patients were included. Twelve patients started SC VDZ after a maximum of three VDZ infusions and 44 patients switched to VDZ SC after at least four VDZ infusions. The mean VDZ trough concentration was 34.4 µg/mL (SD 12.9) after 13 (IQR 11-20) weeks of SC treatment. The mean VDZ trough concentration increased from 20.5 µg/mL to 35.2 µg/mL (P &amp;lt; 0.001) in patients who switched from IV to SC VDZ. Biochemical remission (defined as a C-reactive protein (CRP) ≤ 5 µg/mL with a faecal calprotectin (FC) ≤ 250 µg/g) prior to the switch, VDZ measurements using LC-MS/MS and higher VDZ levels during IV therapy were associated with higher VDZ serum levels during SC therapy. Active smoking and prior use of &amp;gt;1 biologic and/or tofacitinib were associated with lower VDZ levels during SC therapy (table 1). A VDZ trough concentration of ≥ 34.5 µg/mL during SC maintenance therapy predicted corticosteroid free clinical remission with a sensitivity, specificity, positive predictive value and negative predictive value of 60%, 75%, 86% and 43%, respectively. Conclusion VDZ serum concentrations were significantly higher during SC therapy versus IV treatment. A VDZ trough concentrations ≥ 34.5 µg/mL was associated with corticosteroid free remission.

P951 Efficacy and safety of tofacitinib for the treatment of moderate- severe ulcerative colitis in biologic naïve patients

Abstract Background To assess the rates of clinical response at week 8, biochemical response, steroid-free clinical remission, endoscopic healing and safety data at week 26 of tofacitinib in biologic naive patients with moderate-severe ulcerative colitis (UC). Methods This was a retrospective analysis of prospectively collected data extracted from the notes of biologic naïve patients with moderate-severe UC who were treated with tofacitinib in the last 3 years in 5 Greek IBD centers and who had a follow up of at least 26 weeks after initiation of treatment. Tofacitinib was administered at a dose of 10 mg bid for 8 or 16 weeks followed by a maintenance dose of 5mg bid thereafter. Week-8 or -16 clinical response was defined as the reduction in the partial Mayo score of at least 2 points, without concomitant use of any steroid preparation [budesonide, prednis(ol)one, or methylprednisolone]. Steroid free clinical remission at week 26 was defined as a partial Mayo score of ≤1 points without concomitant use of any steroid preparation. Biochemical response at week 26 was defined as any reduction in fecal calprotectin or plasma C-reactive protein concentrations as compared to their baseline levels.Mucosal healing at week 26 was defined as Mayo endoscopic sub-score of ≤1. A safety list of all reported adverse events was completed. Treatment discontinuation due to adverse events was considered as treatment failure, whereas patients needing escalation of the maintenance dose were also considered as non-responders. Results Overall, 41 patients (26 males), aged (mean, SD) 35.2 (12.7) years and disease duration of mean (SD) 6.5 (4.8) years were included. UC was extensive in 22, left-sided in 17, and proctitis in 2 patients. Clinical response was seen in 31 (75.6%) and 34 (82.9%) patients at week 8 and 12 respectively.Biochemical response and steroid free clinical remission at week 26 were seen in 35 (85.4%) patients. Endoscopic healing was seen in 29 (70.7%) patients. Adverse events,which did not lead to treatment discontinuation, occurred in 5 patients (hyperlipidemia n=3, elevated liver enzymesn=1, herpes zoster n=1). Conclusion In this retrospective real-world ongoing cohort study, tofacitinib demonstrated clinical response at week 8 or 16 and steroid free clinical remission at week 26 in more than 75% of biologic naïve patients with moderate-severe UC with a good safety profile.