Follow-up Study to Evaluate the Long-term Safety and Efficacy of Darvadstrocel (Mesenchymal Stem Cell Treatment) in Patients With Perianal Fistulizing Crohn's Disease: ADMIRE-CD Phase 3 Randomized Controlled Trial

Efficacy and Safety of Upadacitinib for Perianal Fistulizing Crohn's Disease: A Post Hoc Analysis of 3 Phase 3 Trials

BACKGROUND & AIMS

Efficacy of upadacitinib, an oral Janus kinase inhibitor, for moderate-to-severe Crohn's disease was demonstrated in phase 3 induction (U-EXCEL, U-EXCEED) and maintenance (U-ENDURE) trials; this post hoc analysis evaluated upadacitinib outcomes in patients with fistulizing disease in these studies.

METHODS

Patients were randomized (2:1) to once daily upadacitinib 45 mg or placebo for 12 weeks. Upadacitinib 45 mg clinical responders were rerandomized (1:1:1) to upadacitinib 15 mg, upadacitinib 30 mg, or placebo for 52 weeks. In patients with fistulas (any and perianal), resolution of drainage, closure of external openings, clinical remission, endoscopic response, and safety were assessed.

RESULTS

Of 1021 patients in U-EXCEL and U-EXCEED, 143 (14.0%) had any fistulas at baseline (66 draining); of these, most (n = 128) had perianal fistulas (56 draining). Greater proportions of patients receiving upadacitinib vs placebo achieved resolution of drainage of perianal fistulas at the end of induction (placebo: 5.6%, n/n = 1/18; upadacitinib 45 mg: 44.7%, n/n = 17/38; P = .003) and maintenance (placebo: 0%, n/n = 0/11; upadacitinib 15 mg: 28.6%, n/n = 4/14; P = .105; upadacitinib 30 mg: 23.1%, n/n = 3/13; P = .223) and closure of perianal fistula external openings (for induction, placebo: 4.8%, n/n = 2/42; upadacitinib 45 mg: 22.1%, n/n = 19/86; P = .013; for maintenance, placebo: 0%, n/n = 0/30; upadacitinib 15 mg: 18.8%, n/n = 6/32; P = .024; upadacitinib 30 mg: 16.0%, n/n = 4/25; P = .037).

CONCLUSION

Patients with fistulizing disease (primarily perianal) treated with upadacitinib achieved higher rates of resolution of drainage, closure of external openings, clinical remission, and endoscopic response vs placebo.

CLINICALTRIALS

gov, Numbers: NCT03345849 (U-EXCEL), NCT03345836 (U-EXCEED), NCT03345823 (U-ENDURE).

Systematic review and meta-analysis of the efficacy and safety of stem cell treatment of anal fistulas

BACKGROUND

Since anal fistulas can be challenging to treat; numerous innovative treatments have been proposed, including stem cell therapy. This systematic review aimed to assess pooled rates of fistula healing and adverse events associated with stem cell treatment.

METHODS

In this PRISMA-compliant systematic review we searched PubMed and Scopus for observational and randomized studies reporting outcomes of stem cell treatment for anal fistulas. The main outcome measures were successful healing and adverse effects of stem cell therapy.

RESULTS

In total, 43 studies incorporating 1160 patients (53.6% male) were included. Underlying fistula etiologies were Crohn's disease (30 studies) and cryptoglandular disease (12 studies). The main origin of stem cells was from adipose tissue (34 studies) or bone marrow (6 studies). The median follow-up duration was 12 months. The combined overall pooled healing rate was 58.1% (95% confidence interval (CI) 51.5-64.7%). The pooled healing rate for Crohn's fistulas was 60.4% (95% CI 54.7-66.2%) with adipose-derived stem cells and 63.6% (95% CI 49.4-77.7%) with bone-marrow-derived cells. The pooled healing rate for cryptoglandular fistulas was 53.8% (95% CI 35.5-72.2%) with adipose-derived stem cells. The pooled complication rate was 37.3% (95% CI 27.1-47.5%). Stem cells were associated with higher odds of anal fistula healing (odds ratio (OR): 1.81, p = 0.003) and similar odds of complications (OR: 1, p = 0.986) compared with controls.

CONCLUSIONS

Stem cell treatment of anal fistulas was associated with promising results. The healing rate in Crohn's anal fistulas was higher than in cryptoglandular fistulas. Bone-marrow-derived stem cells were associated with marginally better outcomes than were adipose-derived cells. This finding suggests that the autoimmune inflammatory etiology of Crohn's disease may respond better to autologous myoblasts than does the infectious etiology of cryptoglandular fistulas.

Darvadstrocel for complex perianal fistulas in Crohn's disease: A systematic review and meta-analysis

BACKGROUND

Local injection of darvadstrocel, a suspension of expanded adipose-derived allogenic mesenchymal stem cells, has been used for treatment-refractory perianal fistulas in Crohn's disease (CD).

OBJECTIVE

This study aimed to investigate efficacy and safety of darvadstrocel for complex perianal fistulas in CD.

METHODS

A systematic search was conducted through April 2024 in relevant databases for observational studies evaluating darvadstrocel. A random-effects meta-analysis model was used to calculate the pooled effect sizes (proportions or incidence rates [IRs]) with 95% confidence intervals (CIs) of effectiveness and safety outcomes. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tool. The I2 value assessed heterogeneity. Sensitivity and subgroup analyses were also conducted.

RESULTS

Twelve studies were included with 595 patients. The pooled rate of patients achieving clinical remission, defined as fistula healing, was 68.1% at month 6 (95% CI 63.4-72.7) and 77.2% (95% CI 70.1-83.8) at month 12. Combined remission, defined as clinical remission and absence of collections >2 cm confirmed by magnetic resonance imaging, was reported in 60.6% and in 69.7% of patients at months 6 and 12, respectively. The rate of patients with treatment failure, defined as no clinical remission at the last follow-up (mean 18.7 months; SD 9.9), was 34.5%. Failure rate was independent of follow-up time (p = 0.85). For effectiveness outcomes, between-study heterogeneity was negligible. Subgroup analysis indicated that none of the covariates modified the treatment effect. Pooled IRs per 100 patient-years of adverse events (AE), serious AEs, perianal abscesses, and reoperations were 19.6, 3.2, 16.9 and 7.1, respectively.

CONCLUSION

Evidence from observational studies supports the efficacy and safety of darvadstrocel for complex perianal fistulas in CD. Studies have reported high fistula healing rates that can be sustained long-term in most patients, with negligible between-study heterogeneity, as well as a favorable safety profile.

A milestone for the therapeutic EV field: FDA approves Ryoncil, an allogeneic bone marrow-derived mesenchymal stromal cell therapy

Small extracellular vesicles (sEVs) derived from mesenchymal stromal cells (MSCs) hold substantial promise for therapeutic applications, including immune modulation and tissue regeneration. However, challenges such as batch-to-batch variability, donor material diversity, and the lack of standardized potency testing remain significant barriers to clinical translation. The recent U.S. Food and Drug Administration (FDA) approval of Ryoncil (remestemcel-L) for steroid-refractory acute graft-versus-host disease (aGvHD) in pediatric patients represents a crucial milestone for MSC-based therapies, offering also valuable insights for the development of MSC-EV therapies. This approval highlights the critical need to address variability and standardization issues in MSC products. Strategies like immortalizing MSCs and expanding them clonally can improve scalability, consistency, and overcome limitations inherent to cellular MSC therapies. With the FDA's decision signaling significant progress, optimizing MSC expansion protocols and refining potency testing methods will be crucial for advancing MSC-EVs as a viable therapeutic option, overcoming current challenges, and expanding clinical applications.

Increasing robustness of in vitro assay for immnosuppressive effect of mesenchymal stromal/stem cells: The role of inflammatory cytokine production by peripheral blood mononuclear cells

Introduction

The Quality by Design (QbD) approach for developing cell therapy products using mesenchymal stromal/stem cells (MSCs) is a promising method for designing manufacturing processes to improve the quality of MSC products. It is crucial to ensure the reproducibility and robustness of the test system for evaluating critical quality attributes (CQAs) in the QbD approach for manufacturing of pharmaceutical products. In this study, we explored the key factors involved in establishing a robust evaluation system for the immunosuppressive effect of MSCs, which can be an example of a CQA in developing and manufacturing therapeutic MSCs for treating graft-versus-host disease, etc, and we have identified method attributes to increase the robustness of a simple in vitro assay to assess the immunosuppressive effects of MSCs.

Methods

We evaluated the performance of an assay system to examine the proliferation of peripheral blood mononuclear cells (PBMCs) activated with the mitogen phytohemagglutinin (PHA) when co-cultured with MSCs, the so-called one-way mixed lymphocyte reaction (MLR) assay. The MLR assay was performed on the same MSCs using 10 PBMC lots from different donors. In addition, 13 cytokine production levels in PHA-stimulated PBMCs were assessed.

Results

The PHA-stimulated proliferation response of PBMCs, the action of MSCs in the MLR test, and the cytokine release of the respective PBMCs significantly differed among the PBMC lots (p < 0.05). A correlation analysis between the amounts of cytokines released by PBMCs and the immunosuppressive potency of MSCs showed that IFNγ, TNFα, CXCL10, PD-L1, HGF, and CCL5 production in PBMCs was significantly correlated with the MSC-mediated inhibition of PBMC proliferation (p < 0.05). Therefore, we selected two PBMC lots with high PBMC proliferation and PHA-stimulated cytokine (such as IFNγ and TNFα) release for the subsequent one-way MLR assay. The robustness of the established test system was confirmed by repeating the assay several times on different days for the same MSCs (coefficient of variation <0.2).

Conclusions

To make robust the MSC immunosuppressive potency assay system, controlling the quality of PBMCs used for the assay is essential. Evaluating the inflammatory cytokine production capacity of PBMCs is effective in assessing the quality of the MLR assay system.

Global trends in surgically based treatment of anal fistula in Crohn's disease: a bibliometric and visualization analysis

BACKGROUND

Crohn's disease (CD) is a chronic, recurrent gastrointestinal disorder characterized by a complex etiology. Among its perianal complications, anal fistulas represent a challenging comorbidity. With the increase of surgical options, a comprehensive bibliometric analysis was deemed necessary to consolidate the vast array of research in this field.

METHODS

We extracted 1608 articles spanning from 1 January 1994, to 1 May 2024, from the Web of Science Core Collection. Using VOSviewer, CiteSpace, and Scimago Graphica for visual analytics, we synthesized key trends across multiple bibliometric indicators, encompassing geographic and institutional contributions, individual authorship, journal prominence, citation metrics, and thematic prevalence.

RESULTS

From the delineated corpus, we identified publications from 325 countries and 5110 research institutions, with the US and UK at the forefront of publication volume and academic impact. The data indicated a leading role for institutions like the Cleveland Clinic and Imperial College London. "Diseases of the Colon and Rectum" emerged as a central journal due to its high publication and citation frequency. Distinctly, the analysis uncovered trending keywords, signifying the field's prioritization on surgical intervention, biologic therapy, imaging modalities, and emerging biological treatments.

CONCLUSION

Our findings elucidate a trajectory toward prominent advancements in CD fistula research. This analysis underscores the field's shift towards integrative treatment strategies, spotlighting the pressing need for comprehensive comparative studies of surgical approaches. It underscores the imperative for robust clinical trials to standardize treatments and extend care to a broader CD patient population.

Improving the therapeutic profile of MSCs: Cytokine priming reduces donor-dependent heterogeneity and enhances their immunomodulatory capacity

Introduction

MSCs exhibit regenerative, anti-inflammatory and immunomodulatory properties due to the large amount of cytokines, chemokines and growth factors they secrete. MSCs have been extensively evaluated in clinical trials, however, in some cases their therapeutic effects are variable. Therefore, strategies to improve their therapeutic potential, such as preconditioning with proinflammatory factors, have been proposed. Several priming approaches have provided non-conclusive results, and the duration of priming effects on MSC properties or their response to a second inflammatory stimulus have not been fully addressed.

Methods

We have investigated the impact of triple cytokine priming in MSCs on their characterization and viability, their transcriptomic profile, the functionality of innate and acquired immune cells, as well as the maintenance of the response to priming over time, their subsequent responsiveness to a second inflammatory stimulus.

Results

Priming MSCs with proinflammatory cytokines (CK-MSCs) do not modify the differentiation capacity of MSCs, nor their immunophenotype and viability. Moreover, cytokine priming enhances the anti-inflammatory and immunomodulatory properties of MSCs against NK and dendritic cells, while maintaining the same T cell immunomodulatory capacity as unstimulated MSCs. Thus, they decrease T-lymphocytes and NK cell proliferation, inhibit the differentiation and allostimulatory capacity of dendritic cells and promote the differentiation of monocytes with an immunosuppressive profile. In addition, we have shown for the first time that proinflammatory priming reduces the variability between different donors and MSC origins. Finally, the effect on CK-MSC is maintained over time and even after a secondary inflammatory stimulus.

Conclusions

Cytokine-priming improves the therapeutic potential of MSCs and reduces inter-donor variability.

Microbial and Transcriptomic Landscape Associated With Neutrophil Extracellular Traps in Perianal Fistulizing Crohn's Disease

BACKGROUND

Perianal fistulizing Crohn's disease (pfCD) poses significant healing challenges, closely associated with neutrophil extracellular traps (NETs). This study aimed to investigate the microbe-host interactions influencing NETs in pfCD.

METHODS

From January 2019 to July 2022, patients with pfCD were screened at Ren Ji Hospital. Patients in remission following comprehensive treatment were recruited. We documented clinical characteristics, medication regimens, healing outcomes, and infliximab levels in fistula tissues. NET positivity was confirmed by positive results in citrullinated histone H3 (CitH3) enzyme-linked immunosorbent assay (ELISA) and dual immunofluorescence staining for myeloperoxidase and CitH3. Microbial and transcriptomic profiles from fistula tissues, obtained during surgery, were analyzed using 16S rRNA gene sequencing and RNA sequencing. Differences in microbiome and transcriptomic profiles were evaluated, and their relationships were assessed using Mantel's and Spearman's coefficients.

RESULTS

Significant differences in microbial communities were found between groups (P = .007). Representatively differential microbes such as Prevotella bivia, Streptococcus gordonii, and Bacteroides dorei were enriched in NETs-positive fistulas (P < .05). Functional analysis of microbes revealed reduced ubiquinol biosynthesis and butanoate production in NETs-negative fistulas (P < .05). Transcriptomic analysis indicated increased neutrophil and monocyte infiltration in NETs-positive fistulas, associated with pathways involving bacterial response, neutrophil chemotaxis, secretory processes, and peptidase activity (P < .05). Species prevalent in NETs-positive fistulas correlated positively with immune responses and wound healing pathways, whereas bacteria in NETs-negative fistulas correlated negatively. NETs were negatively associated with tissue infliximab levels (P = .001) and healing outcomes (P = .025).

CONCLUSIONS

Our findings reveal unique microbial and transcriptomic signatures associated with NETs in pfCD, highlighting their profound influence on clinical outcomes.

Evaluation of the Effectiveness and Safety of Mesenchymal Stem Cell Treatment in Fistulising Crohn's Disease: An International Real-Life Retrospective Multicentre Cohort Study

BACKGROUND

Perianal fistulas of Crohn's disease (CD) create a significant burden on patients' lives. However, the efficacy and safety of adipose-derived mesenchymal stem cell treatment are contradicting, and real-world evidence is lacking.

AIMS

To examine the usability of darvadstrocel therapy in managing perianal CD.

METHODS

We enrolled patients with CD and perianal fistulas in this retrospective multicenter study. The primary outcome was perianal clinical remission (defined as all treated fistulas closed) at weeks 26 and 52. Secondary outcomes were clinical response rates (≥ 1 fistulas closed), perianal activity (PDAI), patient satisfaction, and adverse events. Data were recorded at baseline and weeks 12, 26 and 52. Prediction of primary outcomes was performed by logistic regression.

RESULTS

Overall, among 223 patients (male/female ratio: 0.48), perianal clinical remission was achieved in 78.2% and 62.3% until weeks 26 and 52. Baseline PDAI score (OR 0.75), number of fistulas (OR 0.28) and the number of weeks after preparation for surgery (OR 0.98) were associated with treatment failure. The clinical response rates were 84.8% and 79.8% at weeks 26 and 52. Improvement of subjective perianal symptoms was achieved in 77.8% and 78.4% of patients, respectively. Adverse events occurred in 13.5% of patients; perianal abscesses and proctalgia were the most frequently reported.

CONCLUSION

Effectiveness data were higher than in clinical trials. The safety profile was reassuring, and patients' satisfaction was high. Appropriate patient selection, fistula preparation and expertise may help to achieve treatment success.

Predictive modeling to evaluate long-term treatment effectiveness of darvadstrocel in patients with complex perianal fistulas in Crohn's disease

BACKGROUND

Current therapies for complex Crohn's perianal fistulas (CPF) have a limited ability to achieve long-term healing. Darvadstrocel (DVS) is an expanded allogeneic adipose-derived mesenchymal stem cell therapy that has demonstrated efficacy in treating complex CPF in clinical trials. There are, however, limited long-term comparative data with standard of care (SoC). The aim of this study was to combine clinical trial data and real-world evidence using statistical methodologies to predict long-term effectiveness of DVS versus SoC in patients with CPF.

METHODS

Data were pooled from a clinical trial (ADMIRE-CD) and two retrospective chart review studies (INSPECT and PREFACE). Predictive statistical models extrapolated clinical outcomes beyond observed follow-up using parametric curves, which were implemented into a semi-Markov model to obtain the number of patients in remission. The setting was multinational and multicenter. ADMIRE-CD was conducted in 49 hospitals in 7 European countries and Israel. INSPECT used data from the ADMIRE study. PREFACE involved patients from Belgium, France, Germany, Italy, and Spain. The participants were patients with complex CPF treated with DVS or SoC. Times to remission and relapse (clinical, and clinical plus patient-centric remission) were analyzed. Additionally, the proportion of patients in clinical and patient-centric remission was examined.

RESULTS

In total, 513 patients were included in the analysis (ADMIRE-CD [N = 200] and PREFACE [N = 313]). Patients in ADMIRE-CD and PREFACE were similar in age (median [interquartile range, IQR], 36 [20.0] versus 36 [22.0] years, respectively) and gender (males, 54% and 52%, respectively). The median (IQR) duration of Crohn's disease was 9.4 [11.3] years for patients in ADMIRE-CD and 6.5 [12.9] years for patients in PREFACE. The estimated time to remission was shorter for patients treated with DVS versus SoC. The estimated time to relapse was longer for patients treated with DVS versus SoC. A higher estimated proportion of patients treated with DVS versus SoC had clinical and patient-centric remission at 24 months (48% and 35%, respectively) and 48 months (49% and 32%, respectively).

CONCLUSION

This novel approach enabled pooled data from a clinical trial and real-world settings to predict long-term effectiveness of DVS versus SoC in patients with complex CPF.

Autologous Microfragmented Adipose Tissue Injection in Refractory Complex Crohn's Perianal Fistulas: Long-Term Results at 6.7 Years Mean Follow-up

BACKGROUND

Nowadays, there is a clear need for new viable therapeutic options to face complex perianal Crohn's disease (PCD). Results of our previous pilot study demonstrated the efficacy and safety of local injection of autologous microfragmented adipose tissue (MFat) in this setting. This study aims to evaluate the long-term follow-up results in the same cohort of patients.

METHODS

Data on clinical and radiological remission and surgical recurrence rates were prospectively collected on the 15 patients with complex fistulizing PCD refractory to combined bio-surgical therapy, originally treated with local MFat injection, with a mean 6.7 years follow-up.

RESULTS

In our previous study, at 24-week follow-up, combined remission was reported in 66.7% of patients, while clinical remission was achieved in 93% of cases. At a 6.7-year follow-up, 9 of the 10 healed patients maintained remission. The patient with recurrence was successfully reoperated. Three out of 5 patients who failed primary combined remission were retreated, with 2 obtaining combined remission and 1 failing. One patient refused any subsequent treatment due to good quality of life. The last patient presented delayed healing at a 1-year follow-up. Overall success rate after rescue therapy at the final follow-up reached 86.6%. Safety was maintained throughout all follow-up periods.

CONCLUSIONS

This is the longest follow-up published trial on MFat injection for PCD. Our results show that patients who achieved closure in the first 24 weeks sustained response at long-term evaluation. In addition, there may be a rationale in repeating treatment as rescue therapy in not responding to patients.

From promise to practice: CAR T and Treg cell therapies in autoimmunity and other immune-mediated diseases

Autoimmune diseases, characterized by the immune system's attack on the body's own tissues, affect millions of people worldwide. Current treatments, which primarily rely on broad immunosuppression and symptom management, are often associated with significant adverse effects and necessitate lifelong therapy. This review explores the next generation of therapies for immune-mediated diseases, including chimeric antigen receptor (CAR) T cell and regulatory T cell (Treg)-based approaches, which offer the prospect of targeted, durable disease remission. Notably, we highlight the emergence of CD19-targeted CAR T cell therapies, and their ability to drive sustained remission in B cell-mediated autoimmune diseases, suggesting a possible paradigm shift. Further, we discuss the therapeutic potential of Type 1 and FOXP3+ Treg and CAR-Treg cells, which aim to achieve localized immune modulation by targeting their activity to specific tissues or cell types, thereby minimizing the risk of generalized immunosuppression. By examining the latest advances in this rapidly evolving field, we underscore the potential of these innovative cell therapies to address the unmet need for long-term remission and potential tolerance induction in individuals with autoimmune and immune-mediated diseases.

ECCO Guidelines on Therapeutics in Crohn's Disease: Surgical Treatment

This article is the second in a series of two publications on the European Crohn's and Colitis Organisation [ECCO] evidence-based consensus on the management of Crohn's disease. The first article covers medical management; the present article addresses surgical management, including preoperative aspects and drug management before surgery. It also provides technical advice for a variety of common clinical situations. Both articles together represent the evidence-based recommendations of the ECCO for Crohn's disease and an update of prior ECCO Guidelines.

Effectiveness of autologous emulsified stromal vascular fraction tissue injection for the treatment of complex perianal fistulas in inflammatory bowel diseases patients: a pilot study

Complex fistulizing perianal disease is a disabling manifestation of inflammatory bowel disease (IBD), seriously compromising patients 'quality of life'. The success rate of available treatments is quite low, and nearly half of the patients will develop chronically active fistulas or experience fistula recurrence. Mesenchymal stem cell therapy has shown interesting results, but the complexity and the cost of production limit its widespread use. This study aims to report the results of the innovative use of autologous emulsified adipose-derived stromal vascular fraction tissue for treating complex fistulizing perianal disease. From March 2021 to March 2022, 10 patients underwent a two-step procedure: (1) examination under anaesthesia, with loose seton drainage and 4 weeks later and (2) curettage of the fistulous tract, internal fistula closure and an injection of autologous emulsified adipose-derived stromal vascular fraction tissue harvested from the subcutaneous layer of the patient's hip. Clinical and radiological (through magnetic resonance imaging) healing were assessed at 6 months. We included five patients affected by Crohn's disease, three by ulcerative colitis and two by indeterminate colitis. All patients were on concomitant biological therapy (50% on Infliximab). One patient required a re-treatment for a relapse and two different fistulas were separately treated in another one. Out of 12 total procedures performed, clinical healing was achieved in 10 cases (83%), while radiological healing in 6 patients (50%). No adverse events were recorded. Autologous emulsified adipose-derived stromal vascular fraction tissue can represent an effective, safe and cheap add-on therapy for patients with complex perianal fistulas in IBDs.

Closing the internal opening with a rectal advancement flap increases the efficacy of mesenchymal stem cell injection for complex Crohn's disease anal fistulas

BACKGROUND

The efficacy of injections of mesenchymal stem cells (MSC) for anal fistula treatment may be impaired by the persistence of stools passing into the fistula, causing bacterial contamination and a local inflammatory reaction. We aimed to compare remission rates between patients treated by MSC injection with simple sutures and those treated with a rectal advancement flap.

METHODS

This single-center prospective study compared the first patients who underwent internal opening closure with sutures with the subsequent patients treated with a flap. Complete clinical remission was defined as complete closure of the external opening(s) without pain or discharge, and complete radiological remission was defined as a Magnifi-CD score of 0.

RESULTS

We compared the first 42 patients who had sutures with the 20 subsequent patients who had an advancement flap. The median follow-up was 15.5 [8.8-24.9] months. The cumulative incidence of complete clinical response at M12 was 53.8% [38.1-69.6%] in the suture group versus 93.3% [77.4-100.0] in the flap group (p < 0.001). The Magnifi-CD score was 0 for 41.7% [25.5-59.2%]) of patients treated with sutures versus 72.7% [39.0-63.9%]) of patients treated with a flap (p = 0.093). Anal incontinence score did not differ between the two groups. Practicing an advancement flap was the only significant factor associated with complete clinical remission over time (adjusted HR [95% CI] of 2.6 [1.4-4.9], p = 0.003).

CONCLUSIONS

Complete clinical remission rates following MSC injection are significantly higher after closure of the internal opening with a rectal flap than after closure with sutures, without consequences on anal continence.

Adipose-derived mesenchymal stromal cells in clinical trials: Insights from single-cell studies

Mesenchymal Stromal Cells (MSCs) offer tremendous potential for the treatment of various diseases and their healing properties have been explored in hundreds of clinical trials. These trails primarily focus on immunological and neurological disorders, as well as regenerative medicine. Adipose tissue is a rich source of mesenchymal stromal cells and methods to obtain and culture adipose-derived MSCs (AD-MSCs) have been well established. Promising results from pre-clinical testing of AD-MSCs activity prompted clinical trials that further led to the approval of AD-MSCs for the treatment of complex perianal fistulas in Crohn's disease and subcutaneous tissue defects. However, AD-MSC heterogeneity along with various manufacturing protocols or different strategies to boost their activity create the need for standardized quality control procedures and safety assessment of the intended cell product. High-resolution transcriptomic methods have been recently gaining attention, as they deliver insight into gene expression profiles of individual cells, helping to deconstruct cellular hierarchy and differentiation trajectories, and to understand cell-cell interactions within tissues. This article presents a comprehensive overview of completed clinical trials evaluating the safety and efficacy of AD-MSC treatment, together with current single-cell studies of human AD-MSC. Furthermore, our work emphasizes the increasing significance of single-cell research in elucidating the mechanisms of cellular action and predicting their therapeutic effects.

The potential for medical therapies to address fistulizing Crohn's disease: a state-of-the-art review

INTRODUCTION

Crohn's disease (CD) is a chronic, relapsing immune mediated disease, which is one of the two major types of inflammatory bowel disease (IBD). Fistulizing CD poses a significant clinical challenge for physicians. Effective management of CD requires a multidisciplinary approach, involving a gastroenterologist and a GI surgeon while tailoring treatment to each patient's unique risk factors, clinical representations, and preferences.

AREAS COVERED

This comprehensive review explores the intricacies of fistulizing CD including its manifestations, types, impact on quality of life, management strategies, and novel therapies under investigation.

EXPERT OPINION

Antibiotics are often used as first-line therapy to treat symptoms. Biologics that selectively target TNF-α, such infliximab (IFX), have shown high efficacy in randomized controlled trials. However, more than 50% of patients lose response to IFX, prompting them to explore alternative strategies. Current options include adalimumab and certolizumab pegol combination therapies, as well as small-molecule drugs targeting Janus kinases such as Upadacitinib. Furthermore, a promising treatment for complex fistulas is mesenchymal stem cells such as Darvadstrocel (Alofisel), an allogeneic stem cell-based therapy. However, surgical interventions are necessary for complex cases or intra-abdominal complications. Setons and LIFT procedures are the most common surgical options.

Prospective therapeutic targets and recent advancements in the treatment of inflammatory bowel disease

OBJECTIVE

Inflammatory Bowel Disease (IBD) poses a persistent challenge in the realm of gastroenterology, necessitating continual exploration of innovative treatment strategies. The limited efficacy and potential side effects associated with existing therapeutic modalities underscore the urgent need for novel approaches in IBD management. This study aims to examine potential therapeutic targets and recent advancements in understanding the disease's intricate pathogenesis, with a spotlight on the gut microbiome, immune dysregulation, and genetic predispositions.

METHODS

A comprehensive review was conducted to delve into the pressing demand for new avenues in IBD treatment. The study examined potential therapeutic targets such as phosphodiesterase 4 (PDE4) inhibitors, immune system modulators, Tyrosine kinase receptors (TYK), Toll-like receptors (TLRs), modulation of the gut microbiota, stem cell therapy, fibrosis management, interleukins (ILs) regulation, and oxidative stress mitigation. Additionally, advances in precision medicine, biologics, small molecule inhibitors, and microbiome modulation techniques were explored.

RESULTS

The investigation unveiled promising therapeutic targets and provided insights into recent breakthroughs that herald a transformative era in the therapeutic landscape for IBD. Advances in precision medicine, biologics, small molecule inhibitors, and the exploration of microbiome modulation techniques stood out as pivotal milestones in the field of gastroenterology.

CONCLUSIONS

The findings offer renewed hope for enhanced efficacy, reduced side effects, and improved patient outcomes in the treatment of IBD. These innovative approaches necessitate continual exploration and underscore the urgent need for novel strategies in IBD management, potentially revolutionizing the realm of gastroenterology.

Efficacy of injection of autologous adipose tissue in the treatment of patients with complex and recurrent fistula-in-ano of cryptoglandular origin

BACKGROUND

Adipose tissue injections, a rich source of mesenchymal stem cells, have been successfully used to promote anal fistula healing. This study aimed to investigate the efficacy of adipose tissue injection in treating patients with complex and recurrent fistulas of cryptoglandular origin.

METHODS

We conducted a prospective, single-center, open-label, non-randomized, interventional clinical trial from January 2020 to December 2022. We enrolled nine patients, who were evaluated after at least 12 months of follow-up. All patients had seton removal, fistula tract excision or curettage, and a mucosal flap if possible or, alternatively, an internal opening suture. We used a commercially available system to collect and process adipose tissue prior to injection. This system allowed the collection, microfragmentation, and filtration of tissue.

RESULTS

Selected cases included six men and three women with a median age of 42 (range 31-55) years. All patients had an extended disease course period, ranging from 3 to 13 (mean 6.6) years, and a history of multiple previous surgeries, including two to eight interventions (a mean of 4.4 per case). All fistulas were high transsphincteric, four cases horseshoe and two cases with secondary suprasphincteric or peri-elevator tract fistulas. Six cases (66%) achieved complete fistula healing at a mean follow-up of 18 (range 12-36) months. Three cases (33.3%) experienced reduced secretion and decreased anal discomfort.

CONCLUSIONS

In patients with complex and recurrent fistulas, such as the ones described, many from palliative treatments with setons, the adjuvant injection of adipose tissue might help achieve complete healing or improvement in a significant percentage of cases.

CLINICALTRIALS

The study protocol was prospectively registered on ClinicalTrials.gov (NCT04750499).

Use of Darvadstrocel (Allogenic Stem Cell Therapy) for Crohn's Fistulas in Real Clinical Practice: The National Project to Implement Mesenchymal Stem Cell for the Treatment of Perianal Crohn's Fistula (the PRIME Study)

BACKGROUND

Perianal fistulas may affect 15% to 50% of patients with Crohn's disease. Treatment is complex, requiring a multidisciplinary approach. Darvadstrocel (allogenic mesenchymal cells obtained from lipoaspirates) was approved in 2018 by the European and Spanish Agencies of Medicines and Medical Products as a treatment for fistulas in Crohn's disease. Recent guidelines from the European Crohn's and Colitis Organisation and Spanish Working Group on Crohn's Disease and Ulcerative Colitis state that darvadstrocel is effective with a favorable safety profile and a strong level of evidence (n = 2).

OBJECTIVE

Presenting real-world effectiveness data for darvadstrocel in a Spanish population.

DESIGN

Observational retrospective cohort study with prospective data gathering.

SETTINGS

The study was conducted at 14 institutions in Spain.

PATIENTS

From November 2019 to April 2022, all patients (n = 73) treated with darvadstrocel in these institutions were included, fulfilling the following criteria: 1) complex fistula/s in a patient with Crohn's disease; 2) failure of conventional and antitumor necrosis factor treatment; and 3) the absence of collections of >2 cm confirmed by pelvic MRI at the time of surgery.

INTERVENTIONS

Darvadstrocel treatment.

MAIN OUTCOME MEASURES

Clinical response (closure of 50% or more of external openings), complete clinical closure (100% of external openings), and radiological closure (no fluid collection >2 cm, edema, or inflammation) evaluated 6 months after treatment.

RESULTS

Clinical response was observed in 63 patients (86.3%), complete clinical closure in 50 patients (68.5%), and radiological closure in 45 patients (69.2%). Combined clinical and radiological response was observed in 41 patients (63.1%). Not all clinically healed patients had radiological closure, and vice versa. No serious adverse events were reported.

LIMITATIONS

Retrospective nature of the study.

CONCLUSIONS

Study results were consistent with those reported in previous clinical trials, real-world efficacy findings from the INSPIRE study (assessing darvadstrocel effectiveness in Europe, Israel, Switzerland, United Kingdom, and Japan), and previously published literature. Darvadstrocel was effective and demonstrated a favorable safety profile when used in normal clinical practice for the treatment of fistulas in Crohn's disease. See Video Abstract .

USO DE DARVADSTROCEL TERAPIA CON CLULAS MADRE ALOGNICAS PARA FSTULA EN ENFERMEDAD DE CROHN EN LA PRCTICA CLNICA REAL EL PROYECTO NACIONAL PARA IMPLEMENTAR DE CLULAS MADRE MESENQUIMALES PARA EL TRATAMIENTO DE LA FSTULA DE CROHN PERIANAL EL ESTUDIO PRIME

ANTECEDENTES:Las fístulas perianales pueden afectar entre el 15 y el 50% de los pacientes con enfermedad de Crohn. El tratamiento es complejo y requiere un enfoque multidisciplinario. El darvadstrocel (células mesenquimales alogénicas obtenidas a partir de lipoaspirados) fue aprobado en 2018 por las Agencias Europea y Española de Medicamentos y Productos Sanitarios como tratamiento de las fístulas en la EC. Las recientes directrices de la Organización Europea de Crohn y Colitis y del Grupo de Trabajo Español sobre la Enfermedad de Crohn y Colitis Ulcerosa afirman que darvadstrocel es eficaz con un perfil de seguridad favorable y un sólido nivel de evidencia (2).OBJETIVO:Presentar datos de eficacia real de darvadstrocel en población española.DISEÑO:Estudio de cohorte retrospectivo observacional con recopilación prospectiva de datos.ESCENARIO:14 instituciones.PACIENTES:Desde noviembre de 2019 hasta abril de 2022, se incluyeron todos los pacientes (73) tratados con darvadstrocel en estas instituciones, que cumplieron los siguientes criterios: 1) fístula/s compleja/s en un paciente con enfermedad de Crohn; 2) fracaso del tratamiento convencional y anti factor de necrosis tumoral; 3) ausencia de colecciones > 2 cm confirmada por resonancia magnética pélvica en el momento de la cirugía.INTERVENCIONES:Tratamiento con Darvadstrocel.PRINCIPALES MEDIDAS DE RESULTADO:Respuesta clínica (cierre de ≥50% de las aberturas externas), cierre clínico completo (100% de las aberturas externas) y cierre radiológico (sin acumulación de líquido >2 cm, sin edema ni inflamación) evaluados 6 meses después del tratamiento.RESULTADOS:Se observó respuesta clínica en 63 pacientes (86.3%), cierre clínico completo en 50 pacientes (68.5%) y cierre radiológico en 45 pacientes (69.2%). Se observó respuesta clínica y radiológica combinada en 41 pacientes (63.1%). No todos los pacientes clínicamente curados tuvieron cierre radiológico y viceversa. No hubo eventos adversos graves reportados.LIMITACIONES:Estudio retrospectivoCONCLUSIONES:Los resultados del estudio fueron consistentes con los informados en ensayos clínicos anteriores, los hallazgos de eficacia en el mundo real del estudio INSPIRE (que evalúa la efectividad de darvadstrocel en Europa, Israel, Suiza, el Reino Unido y Japón) y la literatura publicada anteriormente. Darvadstrocel fue eficaz y demostró un perfil de seguridad favorable cuando se utiliza en la práctica clínica habitual para el tratamiento de fístulas en la enfermedad de Crohn. (Traducción-Dr. Jorge Silva Velazco ).

Molecular Prospective on Malignant Transformation of Mesenchymal Stem Cells: An Issue in Cell Therapy

Mesenchymal stem cell (MSCs) therapy, as a rapidly developing area of medicine, holds great promise for the treatment of a variety of medical conditions. MSCs are multipotent stem cells that can be isolated from various tissues and could self-renew and differentiate. They secrete cytokines and trophic factors that create a regenerative microenvironment and have immunomodulatory properties. Although clinical trials have been conducted with MSCs in various diseases, concerns regarding the possibility of malignant transformation of these cells have been raised. The studies showed a higher rate of hematological malignancy and carcinogenesis in experimental models after MSC transplantation. The mechanisms underlying malignant transformation of MSCs are complex and not fully understood, but they are believed to involve the presence of special signaling molecules and alterations in cell behavior regulation pathways. Possible pathways that lead to MSCs' oncogenic transformation occur through two mechanisms: spontaneous and stimulated malignant transformation, including cell fusion, fusion proteins, and the tumor microenvironment. MSC-based therapies have the potential to revolutionize medicine, and addressing the issue of malignancy is crucial to ensure their safety and efficacy. Therefore, the purpose of the present review is to summarize the potential mechanisms of the malignant transformation of MSCs. [Figure: see text].

A phase I/II clinical trial of ex-vivo expanded human bone marrow derived allogeneic mesenchymal stromal cells in adult patients with perianal fistulizing Crohn's Disease

BACKGROUND

Perianal fistulas (PF) affect one-third patients with Crohn's disease (CD) with limited therapeutic options. There is dearth of literature on safety and efficacy of bone marrow-derived mesenchymal stromal cells (BMSCs) in this population.

METHODS

An open-label, phase I/II, single-arm study was conducted involving local administration of human allogeneic bone marrow-derived mesenchymal stromal cells in perianal fistula of patients with Crohn's disease refractory to standard therapies. Clinical severity and biomarkers were assessed at baseline and periodically until week 104 , and MRI at week 24 and 104. Primary and secondary objectives were to assess safety and efficacy respectively. Fistula remission was complete closure of fistula openings with < 2 cm perianal collection on MRI, and fistula response was decrease in drainage by ≥ 50%. Change in perianal disease activity index, quality-of-life and Van Assche index on MRI over time was assessed using mixed-effect linear regression model.

RESULTS

Ten patients (male:8, mean age:27.4 ± 12.0years) were recruited. Self-resolving procedure-related adverse events occurred in three patients, with no follow-up adverse events. In intention to treat analysis at week 24, two patients (20%) achieved fistula remission and seven (70%) had fistula response. At week 52, two (20%) patients were in remission and seven (70%) maintained response. At 104 weeks, two (20%) patients maintained response and one (10%) was in remission. Statistically significant decrease in perianal disease activity index (P = 0.008), Van Assche Index (P = 0.008) and improvement in quality-of-life (P = 0.001) were observed over time.

CONCLUSIONS

Allogeneic BMSCs are safe and effective for the treatment of perianal fistulizing CD with significant improvement in clinical severity and radiological healing.

TRIAL REGISTRATION

The study was prospectively registered on Clinical trials registry - India (CTRI), CTRI/2020/01/022743 on 14 January 2020, http://ctri.nic.in .

Therapeutic Prospects of Mesenchymal Stem Cell and Their Derived Exosomes in the Regulation of the Gut Microbiota in Inflammatory Bowel Disease

Mesenchymal stem cells (MSCs) have shown great potential in the treatment of several inflammatory diseases due to their immunomodulatory ability, which is mediated by exosomes secreted by MSCs (MSC-Exs). The incidence of inflammatory bowel disease (IBD) is increasing globally, but there is currently no long-term effective treatment. As an emerging therapy, MSC-Exs have proven to be effective in alleviating IBD experimentally, and the specific mechanism continues to be explored. The gut microbiota plays an important role in the occurrence and development of IBD, and MSCs and MSC-Exs can effectively regulate gut microbiota in animal models of IBD, but the mechanism involved and whether the outcome can relieve the characteristic dysbiosis necessary to alleviate IBD still needs to be studied. This review provides current evidence on the effective modulation of the gut microbiota by MSC-Exs, offering a basis for further research on the pathogenic mechanism of IBD and MSC-Ex treatments through the improvement of gut microbiota.

Insights into treatment of complex Crohn's perianal fistulas

Complex perianal fistula is a common complication of Crohn's disease (CD) which leads to negative impact on patient's quality of life. Successful management of the disease requires a multidisciplinary approach, including a gastroenterologist and a colorectal surgeon, applying combined surgical and medical therapy. One of frequently practiced surgical procedures is seton placement in the fistula tract, which is used to control perianal sepsis and drain the fistula, while preventing recurrent abscess formation.Darvadstrocel, a suspension of expanded, allogeneic, adipose-derived, mesenchymal stem cells, is safe and effective for treatment-refractory complex perianal fistulas in patients with Crohn's disease. Following approval of darvadstrocel, the INSPIRE registry is being conducted in order to evaluate long-term safety and effectiveness of the drug on a large, heterogenous population.An online expert meeting was held from March 20 to March 30, 2023, which provided relevant insights into the decision-making process regarding seton use and obtained feedback on the first experiences with darvadstrocel. The aim of this article is to present the perspectives from gastroenterologists and colorectal surgeons practicing in Czechia, Hungary, Israel, Lithuania, Serbia, and Slovenia in topics such as diagnosis and treatment options for patients with complex Crohn's perianal fistulas (CPF), specifically focusing on the use of setons and darvadstrocel.During this virtual session, unavailability of comprehensive data on safety and efficacy of available treatment procedures was emphasized as an important obstacle towards development of standardized recommendations and improvement of outcomes in treatment of (CPF). Furthermore, achieving consensus in seton use, duration of its placement, and frequency of change is recognized as one of CPF treatments major challenges. Despite these issues, it is important to promote better understanding and treatment of complex perianal fistulas in order to improve the quality of life of those affected by this condition.

A Prospective, Single-Arm Study to Evaluate the Safety and Efficacy of an Autologous Blood Clot Product in the Treatment of Anal Fistula

BACKGROUND

Surgical treatment of complex perianal fistula is technically challenging, associated with risk of failure, and may require multiple procedures. In recent years, several biologic agents have been developed for permanently eradicating anal fistulous disease with variable success. In this study, the treatment is an autologous whole-blood product created from the patients' blood. It forms a provisional matrix that was found to be safe and effective in healing acute and chronic cutaneous wounds.

OBJECTIVE

The study aimed to assess the efficacy and safety of an autologous blood clot product as a treatment for transsphincteric perianal fistulas.

DESIGN

A prospective single-arm study.

SETTINGS

A single tertiary medical center.

PATIENTS

Patients with simple or complex transsphincteric fistulas confirmed by MRI were included in the study. Cause was either cryptoglandular or Crohn's disease related (in the absence of active luminal bowel disease).

INTERVENTION

The outpatient procedure was performed under general anesthesia and consisted of: 1) physical debridement and cleansing of the fistula tract; 2) suture closure of the internal opening; and 3) instillation of the autologous blood clot product into the entire tract.

MAIN OUTCOME MEASURES

Safety and efficacy at 6- and 12-months after surgery.

RESULTS

Fifty-three patients (77% men) with a median age of 42 (20-72) years were included in the study. Three patients withdrew consent, and 1 patient was lost to follow-up. At the time of this interim analysis, 49 and 33 patients completed the 6- and 12-month follow-up period. Thirty-four of the 49 patients achieved complete healing (69%) at 6 months, but 20 of the 33 patients (60%) achieved healing after 1 year. All patients who achieved healing at 6 months remained healed at the 1-year mark. In a subgroup analysis of patients with Crohn's disease, 7 of 9 patients completed 1-year follow-up, with 5 patients (71%) achieving clinical remission. No major side effects or postoperative complications were noted, but 2 adverse events occurred (admission for pain control and coronavirus 2019 infection).

LIMITATIONS

Noncomparative single-arm pilot study.

CONCLUSIONS

Treatment with an autologous blood clot product in perianal fistular disease was found to be feasible and safe, with an acceptable healing rate in both cryptoglandular and Crohn's disease fistula-in-ano. Further comparative assessment is required to determine its potential role in the treatment paradigm of fistula-in-ano. See Video Abstract .

BRAZO PARA EVALUAR LA SEGURIDAD Y EFICACIA DE RDVER, UN COGULO DE SANGRE AUTLOGO, EN EL TRATAMIENTO DE LA FSTULA ANAL

ANTECEDENTES:El tratamiento quirúrgico de la fístula perianal compleja es técnicamente desafiante, se asocia con riesgo de fracaso y puede requerir múltiples procedimientos. En los últimos años, se han desarrollado varios agentes biológicos con el fin de erradicar permanentemente la enfermedad fistulosa anal con éxito variable. El tratamiento RD2-Ver.02 es un producto de sangre total autólogo creado a partir de la sangre de los pacientes, que forma una matriz provisional que resultó segura y eficaz para curar heridas cutáneas agudas y crónicas.OBJETIVO:Evaluar la eficacia y seguridad de RD2-Ver.02 como tratamiento para las fístulas perianales transesfinterianas.DISEÑO:Un estudio prospectivo de un solo brazo.LUGARES:Un único centro médico terciario.PACIENTES:Se incluyeron en el estudio pacientes con fístulas transesfinterianas simples o complejas confirmadas mediante resonancia magnética. La etiología fue criptoglandular o relacionada con la enfermedad de Crohn (en ausencia de enfermedad intestinal luminal activa).INTERVENCIÓN:El procedimiento ambulatorio se realizó bajo anestesia general y consistió en: 1) desbridamiento físico y limpieza del trayecto fistuloso; 2) cierre con sutura de la abertura interna; y 3) instilación de RD2-Ver.02 en todo el tracto.PRINCIPALES MEDIDAS DE VALORACIÓN:Seguridad y eficacia a los 6 y 12 meses después de la cirugía.RESULTADOS:Se incluyeron en el estudio 53 pacientes (77% varones) con una mediana de edad de 42 (20-72) años. Tres pacientes retiraron su consentimiento y un paciente se perdió durante el seguimiento. En el momento de este análisis intermedio, 49 y 33 pacientes completaron el período de seguimiento de 6 y 12 meses, respectivamente. Treinta y cuatro (34) pacientes lograron una curación completa (69%) a los 6 meses, mientras que 20 de 33 pacientes (60%) lograron una curación después de un año. Todos los pacientes que lograron la curación a los 6 meses permanecieron curados al año. En un análisis de subgrupos de pacientes con enfermedad de Crohn, 7/9 pacientes completaron un seguimiento de un año y 5 pacientes (71%) alcanzaron la remisión clínica. No se observaron efectos secundarios importantes ni complicaciones postoperatorias, mientras que ocurrieron 2 eventos adversos (ingreso para control del dolor e infección por COVID-19).LIMITACIONES:Estudio piloto no comparativo de un solo brazo.CONCLUSIONES:Se encontró que el tratamiento con RD2-Ver.02 en la enfermedad fístula perianal es factible y seguro, con una tasa de curación aceptable tanto en la fístula criptoglandular como en la de Crohn en el ano. Se requiere una evaluación comparativa adicional para determinar su papel potencial en el paradigma de tratamiento de la fístula anal. (Pre-proofed version ).

Innovative cellular therapies for autoimmune diseases: expert-based position statement and clinical practice recommendations from the EBMT practice harmonization and guidelines committee

Autoimmune diseases (ADs) are characterized by loss of immune tolerance, high chronicity, with substantial morbidity and mortality, despite conventional immunosuppression (IS) or targeted disease modifying therapies (DMTs), which usually require repeated administration. Recently, novel cellular therapies (CT), including mesenchymal stromal cells (MSC), Chimeric Antigen Receptors T cells (CART) and regulatory T cells (Tregs), have been successfully adopted in ADs. An international expert panel of the European Society for Blood and Marrow Transplantation and the International Society for the Cell and Gene Therapy, reviewed all available evidence, based on the current literature and expert practices, on use of MSC, CART and Tregs, in AD patients with rheumatological, neurological, and gastroenterological indications. Expert-based consensus and recommendations for best practice and quality of patient care were developed to support clinicians, scientists, and their multidisciplinary teams, as well as patients and care providers and will be regularly updated.

The use of core descriptors from the ENiGMA code study in recent literature: a systematic review

AIM

The heterogeneity in data quality presented in studies regarding Crohn's anal fistula (CAF) limit extrapolation into clinical practice. The ENiGMA collaborators established a core descriptor set to standardize reporting of CAF. The aim of this work was to quantify the use of these descriptors in recent literature.

METHOD

We completed a systematic review of PubMed and the Cochrane Library, extracting publications from the past 10 years specific to the clinical interventions and outcomes of CAF, and reported in line with PRISMA guidance. Each article was assessed for inclusion of ENiGMA descriptors. The median number of descriptors per publication was evaluated along with the overall frequency of each individual descriptor. Use of ENiGMA descriptors was compared between medical and procedural publications.

RESULTS

Ninety publications were included. The median number of descriptors was 15 of 37; 16 descriptors were used in over half of the publications while 17 were used in fewer than a third. Descriptors were more frequently used in procedural (n = 16) than medical publications (n = 14) (p = 0.031). In procedural publications, eight descriptors were more frequently used including Faecal incontinence, Number of previous fistula interventions, Presence and severity of anorectal stenosis and Current proctitis. Medical publications were more likely to include Previous response to biological therapy and Duration and type of current course of biological therapy.

CONCLUSION

With many descriptors being used infrequently and variations between medical and procedural literature, the colorectal community should assess the need for all 37 descriptors.

Updates and Challenges in ENS Cell Therapy for the Treatment of Neurointestinal Diseases

Neurointestinal diseases represent a significant challenge in clinical management with current palliative approaches failing to overcome disease and treatment-related morbidity. The recent progress with cell therapy to restore missing or defective components of the gut neuromusculature offers new hope for potential cures. This review discusses the progress that has been made in the sourcing of putative stem cells and the studies into their biology and therapeutic potential. We also explore some of the practical challenges that must be overcome before cell-based therapies can be applied in the clinical setting. Although a number of obstacles remain, the rapid advances made in the enteric neural stem cell field suggest that such therapies are on the near horizon.

Perianal fistulizing Crohn's disease: Current perspectives on diagnosis, monitoring and management with a focus on emerging therapies

Crohn's disease (CD), a chronic inflammatory bowel disorder, manifests in various phenotypes, with fistulizing perianal CD (CD-PAF) being one of its most severe phenotypes. Characterized by fistula formation and abscesses, CD-PAF impacts 17% to 34% of all CD cases and with a significantly deleterious impact on patient's quality of life, while increasing the risk for anorectal cancers. The pathogenesis involves a complex interplay of genetic, immunological and environmental factors, with cytokines such as tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) playing pivotal roles. Diagnostic protocols require a multi-disciplinary approach including colonoscopy, examination under anesthesia and magnetic resonance imaging. In terms of treatment, biologics alone often prove inadequate, making surgical interventions such as setons and fistula surgeries essential. Emerging therapies such as mesenchymal stem cells are under study. The South Asian context adds layers of complexity, including diagnostic ambiguities related to high tuberculosis prevalence, healthcare access limitations and cultural stigma toward perianal Crohn's disease and ostomy surgery. Effective management necessitates an integrated, multi-disciplinary approach, especially in resource-constrained settings. Despite advances, there remain significant gaps in understanding the disease's pathophysiology and a dearth of standardized outcome measures, underscoring the urgent need for comprehensive research.

Contemporary management of anorectal fistula

Anorectal fistula is a common, chronic condition, and is primarily managed surgically. Herein, we provide a contemporary review of the relevant etiology and anatomy anorectal fistula, treatment recommendations that summarize relevant outcomes and alternative considerations, in particular when to refer to a fistula expert.

Effectiveness and safety of darvadstrocel in patients with complex perianal fistulizing Crohn's disease: a systematic review

Background

Managing complex perianal fistulizing Crohn's disease (CD) remains challenging, despite current medical and surgical treatment approaches. Darvadstrocel, a therapy utilizing adipose-derived stem cells, shows promise in promoting tissue regeneration and healing, offering a novel and effective treatment for fistula management.

Method

A systematic literature search was conducted on PubMed and Scopus to identify studies involving patients with complex perianal fistulizing CD treated with darvadstrocel.

Results

In total, 2 randomized controlled trials (RCT), 5 observational studies with retrospective data collection and 2 observational studies with prospective design were included in the final review. Data from the European ADMIRE-CD RCT demonstrated that darvadstrocel is superior to placebo in terms of clinical and imaging improvement over both the short and long term. These findings align with the prospective studies analyzed in this systematic review. The rate of treatment-emergent adverse events in the ADMIRE-CD trial's RCTs was similar in both the darvadstrocel and control groups, with perianal abscess being the most common adverse event up to 52 weeks after drug administration. Retrospective studies indicated no side-effects beyond 52 weeks.

Conclusions

Darvadstrocel appears to be a new, potentially effective and safe treatment option for the management of complex perianal fistulas. However, more randomized clinical trials are needed to evaluate the efficacy and safety profile of the drug.

Mesenchymal stem cell therapy for Crohn's perianal fistula-a real-world experience

AIM

Remission rates of medically and surgically treated complex perianal fistulas in Crohn's disease are low. Recently, trials have demonstrated the potential for long-term remission with local injection of allogeneic adipose-derived mesenchymal stem cells (darvadstrocel). Our aim was to analyse outcomes from our real-world experience with this new treatment.

METHODS

All patients with Crohn's disease suffering complex perianal fistulas who consecutively underwent administration of darvadstrocel at two centres were followed up and evaluated. Patients were assessed for clinical remission, response, failure, and any complications during follow-up. The results of all patients with a minimum of 3 months' follow-up are presented.

RESULTS

Thirty-three patients with Crohn's disease and complex perianal fistulas were included. Of these, 20 (61%) experienced clinical remission that was maintained for a mean follow-up of 14 (3-32) months. A total of 24 of 33 (73%) experienced at least 3 months of clinical remission, with four later having recurrence (3-12 months). Among the remaining nine patients who did not experience clinical remission, two (6%) had partial remission (such as one of two fistulas closing), two (6%) showed signs of response but not remission, and five (15%) showed no signs of healing. The mean time to maintained clinical remission was 6 weeks (range 2 weeks to 6 months), and there were no severe adverse events.

CONCLUSION

In this real-world experience, treatment of Crohn's disease complex perianal fistulas with darvadstrocel had a 61% success rate for maintained clinical remission.

Enhancing surgical precision: unveiling the impact of preoperative colonoscopy in anal fistula patients

BACKGROUND

Anal fistula is a common benign anorectal disease that often requires surgical intervention for effective treatment. In recent years, preoperative colonoscopy as a diagnostic tool in patients with anal fistula has garnered increasing attention due to its potential clinical application value. By investigating underlying inflammatory bowel disease (IBD), polyps, and other abnormalities, preoperative colonoscopy can offer insights to refine surgical strategies and improve patient outcomes.

METHODS

This retrospective study focused on 1796 patients with various benign anorectal diseases who underwent preoperative intestinal endoscopy and met surgical criteria within the preceding three years at the First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine. Among these patients, 949 diagnosed with anal fistula comprised group A, while 847 patients without anal fistula were assigned to group B for comparison. The investigation encompassed an analysis of general patient information, endoscopic findings, polyp histopathology, distribution of bowel inflammation sites, and results of inflammatory bowel disease assessments between the two patient cohorts. A subgroup analysis was also conducted on 2275 anal fistula patients with no surgical contraindications. This subgroup was categorized into Group A (949 patients who underwent preoperative intestinal endoscopy) and Group C (1326 patients who did not undergo preoperative colonoscopy). The study compared the rates of detecting endoscopic lesions and IBD-related findings between the two subgroups.

RESULTS

The study initially confirmed the comparability of general patient information between groups A and B. Notably, the abnormal detection rate in group A was significantly higher than in group B (P < 0.01). In terms of endoscopic findings, the anal fistula group (group A) exhibited higher rates of detecting bowel inflammation, inflammatory bowel disease, and polyps compared to the non-anal fistula group (group B) (P < 0.05). The distribution of inflammation locations indicated higher detection rates in the terminal ileum, ileocecal region, and ascending colon for group A compared to group B (P < 0.05). Although the incidence of IBD in group A was higher than in group B, this difference did not reach statistical significance (P > 0.05). Subsequently, the analysis of the subgroup (groups A and C) revealed a significant disparity in intestinal endoscopic detection rates (P < 0.01) and statistically significant differences in detecting IBD (P < 0.05) and Crohn's disease (P < 0.05) between the two anal fistula subgroups.

CONCLUSIONS

The findings of this study underscore the substantial clinical value of preoperative colonoscopy in the comprehensive evaluation of patients with anal fistula. Preoperative colonoscopy aids in ruling out localized perianal lesions caused by underlying inflammatory bowel disease, thereby mitigating the likelihood of missed diagnoses and enhancing treatment outcomes. This research highlights the importance of incorporating preoperative colonoscopy as a valuable diagnostic tool in managing anal fistula patients.

Cellular microenvironment: a key for tuning mesenchymal stem cell senescence

Mesenchymal stem cells (MSCs) possess the ability to self-renew and differentiate into multiple cell types, making them highly suitable for use as seed cells in tissue engineering. These can be derived from various sources and have been found to play crucial roles in several physiological processes, such as tissue repair, immune regulation, and intercellular communication. However, the limited capacity for cell proliferation and the secretion of senescence-associated secreted phenotypes (SASPs) pose challenges for the clinical application of MSCs. In this review, we provide a comprehensive summary of the senescence characteristics of MSCs and examine the different features of cellular microenvironments studied thus far. Additionally, we discuss the mechanisms by which cellular microenvironments regulate the senescence process of MSCs, offering insights into preserving their functionality and enhancing their effectiveness.

The Future of Advanced Therapies for Pediatric Crohn's Disease

Pediatric Crohn's disease commonly presents with moderate-to-severe intestinal inflammation with a greater risk of complications if remission is not achieved. Anti-tumor necrosis factor therapies have offered the possibility of deep and durable remission; however, many children do not respond or no longer respond over time. Further, some children do not require broader systemic immunosuppression to achieve remission and are better served by an alternative treatment strategy. Proper utilization of advanced biologic and small-molecule therapies, which have become available for adult patients since anti-tumor necrosis factor medications, is paramount for tighter disease control for a large proportion of children. Newer advanced therapies such as anti-integrin and anti-interleukin biologics, and several small-molecule agents capitalize on various mechanisms through narrower immunologic targets and reduced immunogenicity. Given limited regulatory approvals of these agents for use in children with Crohn's disease, clinicians continue to rely on data extrapolated from clinical trials in adult patients, sparse pediatric studies, and a growing real-world experience for treatment selection and optimization. In this article, we discuss currently available treatment options, pipeline drugs, and relevant data as they pertain to some of the most pressing clinical challenges faced in treating pediatric Crohn's disease.

Stem cells in treatment of crohn's disease: Recent advances and future directions

BACKGROUND AND AIM

Crohn's disease (CD) is an inflammatory bowel disease that can affect any part of the intestine. There is currently no recognized cure for CD because its cause is unknown. One of the modern approaches that have been suggested for the treatment of CD and other inflammatory-based disorders is cell therapy.

METHODS

Search terms were stem cell therapy, CD, adipose-derived stem cells, mesenchymal stem cells, and fistula. Of 302 related studies, we removed duplicate and irrelevant papers and identified the ones with proper information related to our scope of the research by reviewing all the abstracts and categorizing each study into the proper section.

RESULTS AND CONCLUSION

Nowadays, stem cell therapy is widely implied in treating CD. Although mesenchymal and adipose-derived tissue stem cells proved to be safe in treating Crohn's-associated fistula, there are still debates on an optimal protocol to use. Additionally, there is still a lack of evidence on the efficacy of stem cell therapy for intestinal involvement of CD. Future investigations should focus on preparing a standard protocol as well as luminal stem cell therapy in patients.

Novel Approach in Rectovaginal Fistula Treatment: Combination of Modified Martius Flap and Autologous Micro-Fragmented Adipose Tissue

In this paper, we introduce an innovative therapeutic approach for managing rectovaginal fistulas (RVF), by combining the modified Martius flap and micro-fragmented adipose tissue (MFAT) enriched with mesenchymal stem cells (MSC). This novel approach aims to deal with the difficulties associated with RVF, a medically complex condition with a lack of effective treatment options. We present the case of a 45-year-old female patient with a 15-year history of Crohn's disease (CD). During the preceding eight years, she had encountered substantial difficulties resulting from a rectovaginal fistula (RVF) that was active and considerable in size (measuring 3.5 cm in length and 1 cm in width). Her condition was accompanied by tissue alterations at both the vaginal and rectal openings. Following her admission to our hospital, the patient's case was discussed during both surgical and multidisciplinary hospital team (IRB) meetings. The team decided to combine a modified Martius flap with autologous MFAT containing MSCs. The results were remarkable, leading to comprehensive anatomical and clinical resolution of the RVF. Equally significant was the improvement in the patient's overall quality of life and sexual satisfaction during the one-year follow-up period. The integration of the modified Martius flap with MFAT emerges as a highly promising approach for addressing CD-related RVFs that had historically been, and still are, difficult to treat, given their often refractory nature and low healing success rates.

Up-to-date meta-analysis of long-term evaluations of mesenchymal stem cell therapy for complex perianal fistula

BACKGROUND

Local mesenchymal stem cell (MSC) therapy for complex perianal fistulas (PFs) has shown considerable promise. But, the long-term safety and efficacy of MSC therapy in complex PFs remain unknown.

AIM

To explore the long-term effectiveness and safety of local MSC therapy for complex PFs.

METHODS

Sources included the PubMed, EMBASE, and Cochrane Library databases. A standard meta-analysis was performed using RevMan 5.3.

RESULTS

After screening, 6 studies met the inclusion criteria. MSC therapy was associated with an improved long-term healing rate (HR) compared with the control condition [odds ratio (OR) = 2.13; 95% confidence interval (95%CI): 1.34 to 3.38; P = 0.001]. Compared with fibrin glue (FG) therapy alone, MSC plus FG therapy was associated with an improved long-term HR (OR = 2.30; 95%CI: 1.21 to 4.36; P = 0.01). When magnetic resonance imaging was used to evaluate fistula healing, MSC therapy was found to achieve a higher long-term HR than the control treatment (OR = 2.79; 95%CI: 1.37 to 5.67; P = 0.005). There were no significant differences in long-term safety (OR = 0.77; 95%CI: 0.27 to 2.24; P = 0.64).

CONCLUSION

Our study indicated that local MSC therapy promotes long-term and sustained healing of complex PFs and that this method is safe.

The Impact of Cellular Therapies on Gastrointestinal Diseases: Applications and Challenges

Gastrointestinal diseases are highly prevalent, and their burden significantly impacts the quality of life of affected individuals. Inflammatory and immune-mediated intestinal diseases usually have a chronic course without adequate therapeutic modalities. Although much has been reported to comprehend these diseases, many remain resistant and refractory to conventional treatment approaches. Therefore, recent approaches to cellular therapy using stem cells, like hematopoietic stem cells and mesenchymal stem cells, and other cellular immunosuppressive modalities, like T-regulatory cells, were introduced and investigated in treating gastrointestinal diseases. We aimed to conduct a literature review to discuss the applications and challenges of cellular therapeutics in gastrointestinal diseases. Evidence from published clinical trials supports the safety and efficacy of cellular treatment in different immune-mediated and inflammatory gastrointestinal diseases. They can offer a longer duration of remission, being able to adjust the dysregulated immune system. However, there are various challenges to be considered by future trials, including the limitations of current clinical trials, challenges in retrieval and application of these therapeutics, and their mutagenesis potential.

An International Society for Cell and Gene Therapy Mesenchymal Stromal Cells (MSC) Committee perspectives on International Standards Organization/Technical Committee 276 Biobanking Standards for bone marrow-MSCs and umbilical cord tissue-derived MSCs for research purposes

The rapidly growing field of mesenchymal stromal cell (MSC) basic and translational research requires standardization of terminology and functional characterization. The International Standards Organization's (ISO) Technical Committee (TC) on Biotechnology, working with extensive input from the International Society for Cells and Gene Therapy (ISCT), has recently published ISO standardization documents that are focused on biobanking of MSCs from two tissue sources, Wharton's Jelly, MSC(WJ) and Bone Marrow, MSC(M)), for research and development purposes and development. This manuscript explains the path towards the consensus on the following two documents: the Technical Standard ISO/TS 22859 for MSC(WJ) and the full ISO Standard 24651 for MSC(M) biobanking. The ISO standardization documents are aligned with ISCT's MSC committee position and recommendations on nomenclature because there was active input and incorporation of ISCT MSC committee recommendations in the development of these standards. The ISO standardization documents contain both requirements and recommendations for functional characterization of MSC(WJ) and MSC(M) using a matrix of assays. Importantly, the ISO standardization documents have a carefully defined scope and are meant for research use of culture expanded MSC(WJ) and MSC(M). The ISO standardization documents can be updated in a revision process and will be systematically reviewed after 3-5 years as scientific insights grow. They represent international consensus on MSC identity, definition, and characterization; are rigorous in detailing multivariate characterization of MSCs and represent an evolving-but-important first step in standardization of MSC biobanking and characterization for research use and development.

Network meta-analysis: efficacy and safety of treatments for fistulising Crohn's disease

INTRODUCTION

Fistulas are a debilitating complication of Crohn's disease and treatment options remain limited. There is a lack of head-to-head comparisons between treatments. To our knowledge, this is the first network meta-analysis on the efficacy of medical therapies in achieving fistula remission and maintenance of fistula closure in Crohn's disease.

METHODS

Biomedical databases and the Cochrane Central Registry were searched between 1978 and 2022 for randomized controlled trials (RCTs) reporting on treatments. A network meta-analysis was performed using the frequentist model with pooled relative risks (RRs) and P -scores used to rank treatments.

RESULTS

Twenty-five RCTs were included for analysis with 2239 patients included. At the 16-24 week time point, infliximab produced the only statistically significant result with the 5 mg/kg dose proving the most effective [RR, 2.30; 95% confidence interval (CI), 1.40-3.77]. At 44 weeks, ustekinumab was found to be most superior with it being 2.38 times (RR, 2.38; 95% CI, 1.24-4.56) more superior to placebo, with adalimumab (RR, 2.06; 95% CI, 1.06-3.99) and infliximab 5 mg/kg (RR, 1.68; 95% CI, 1.03-2.75) also producing a statistically significant result.

CONCLUSION

Despite infliximab being favoured in international guidelines for the treatment of perianal fistulising Crohn's disease, biologics such as ustekinumab, vedolizumab and adalimumab show promising results.

The history of Crohn's perianal fistula treatment with mesenchymal stem cells: the story of darvadstrocel

INTRODUCTION

This study provides an overview of the development of the first drug authorized for use in cell therapy.

AREAS COVERED

We analyze the case of darvadstrocel, an example of a successful cell-therapy drug used worldwide to treat Crohn's perianal fistula. A bibliographic-historical analysis of the first cellular treatment approved by the EMA, including relevant aspects concerning the authors, who were involved in the whole process. We would like to highlight the following messages: Development: The article describes the development process of the drug, from initial concept through the clinical trial phases. Learning from failure: In describing the development of darvadstrocel, the authors highlight the importance of learning from failures, which is crucial to achieving successful outcomes. Collaboration: The article underscores the need for collaboration between public and private institutions to facilitate the advancement of cell-therapy drugs and ensure efficiency while adhering to regulatory guidelines.

EXPERT OPINION

Regulatory requirements play a crucial role in the design and development of advanced therapies such as cell-therapy drugs. The findings of this study underscore the significance of appropriate disease application, meticulous donor selection, robust manufacturing processes, and proper therapy administration. Only by adopting these measures can cell-therapy drugs successfully complete all phases of the clinical trial process.

[Stem Cell Therapy for Complex Anal Fistula in Crohn`s Disease: Current Evidence and Future Perspectives]

Despite progress in multidisciplinary diagnostic and therapeutic strategies, complex anal fistulas associated with Crohn's disease remain a challenge for both medical and surgical management. Conventional surgical techniques such as flap procedures or LIFT are still associated with considerable persistence and recurrence rates. Based on this background, results of stem cell therapy for Crohn's anal fistula have shown promising results and are a sphincter-preserving technique. In particular, adipose-derived, allogeneic stem cell therapy (Darvadstrocel) has shown encouraging healing rates within the randomised controlled ADMIRE-CD trial, which were reproducible in "real world" data of limited clinical studies. The current evidence has led to the integration of allogeneic stem cell therapy into international guidelines. To date, the definitive status of allogeneic stem cells in the multidisciplinary treatment algorithm for complex anal fistulas associated with Crohn's disease cannot be evaluated.

Mesenchymal stem cells transplantation for perianal fistulas: a systematic review and meta-analysis of clinical trials

BACKGROUND

Perianal fistulas, characterised as granulomatous inflammation of fistulas around the anal canal, are associated with significant morbidity resulting in a negative impact on quality of life and a tremendous burden to the healthcare system. Treatment of anal fistulas usually consists of anal surgery; however, results of closure rates are not satisfactory especially with complex perianal fistulas, after which many patients may suffer from anal incontinence. Recently, the administration of mesenchymal stem cells (MSCs) has shown promising efficacy. Herein, we aim to explore whether MSCs are effective for complex perianal fistulas and if they have either short-term, medium-term, long-term or over-long-term efficacy. Additionally, we want to elucidate whether factors such as drug dosage, MSC source, cell type, and disease aetiology influence treatment efficacy. We searched four online databases and analysed data based on information within the clinical trials registry. The outcomes of eligible trials were analysed with Review Manager 5.4.1. Relative risk and related 95% confidence interval were calculated to compare the effect between the MSCs and control groups. In addition, the Cochrane risk of bias tool was applied to evaluate the bias risk of eligible studies. Meta-analyses showed that therapy with MSCs was superior to conventional treatment for complex perianal fistulas in short-, long- and over-long-term follow-up phases. However, there was no statistical difference in treatment efficacy in the medium term between the two methods. Subgroup meta-analyses showed factors including cell type, cell source and cell dosage were superior compared to the control, but there was no significant difference between different experimental groups of those factors. Besides, local MSCs therapy has shown more promising results for fistulas as a result of Crohn's Disease (CD). Although we tend to maintain that MSCs therapy is effective for cryptoglandular fistulas equally, more studies are needed to confirm this conclusion in the future.

SHORT CONCLUSION

MSCs Transplantation could be a new therapeutic method for complex perianal fistulas of both cryptoglandular and CD origin showing high efficacy in the short-term to over-long-term phases, as well as high efficacy in sustained healing. The difference in cell types, cell sources and cell dosages did not influence MSCs' efficacy.

Efficacy and safety of mesenchymal stem cells in the treatment of perianal fistulas in Crohn's disease: a meta-analysis of randomized controlled trials

OBJECTIVES

Local mesenchymal stem cell (MSC) therapy for perianal fistulas in Crohn's disease (CD) has yielded promising results, but it still remains controversial. In this study, we aimed to conduct a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of MSC therapy for perianal CD (pCD).

METHODS

RCTs reporting MSC therapy for perianal fistulas in CD were searched and included. The effectiveness and safety data were analyzed using RevMan 5.3.

RESULTS

A total of 7 RCTs were included in this meta-analysis. The analysis showed that patients receiving MSC therapy presented a higher healing rate (HR) of pCD than those in the control group (odds ratio (OR)=1.42; 95% confidence interval (CI) 1.18, 1.71; P=0.0002). Compared with placebo (saline solution), MSC therapy improved the HR of pCD (OR=1.85; 95% CI 1.32, 2.60; P=0.0004). MSC therapy showed significant long-term efficacy (OR=1.36; P=0.009; 95% CI 1.08, 1.71). When MRI was used to evaluate fistula healing, a pooled analysis showed that the MSC group achieved a higher HR than the control group (OR=1.95; 95% CI 1.33, 2.87; P=0.0007). Allogeneic MSC therapy was superior to the control treatment in improving HR (OR = 1.97; 95% CI 1.40, 2.75; P<0.001). Furthermore, no significant differences were observed between MSC therapy and placebo in terms of adverse events (AEs) (OR = 1.16; 95% CI 0.76, 1.76; P = 0.48). None of the AEs were judged to be related to MSC treatment.

CONCLUSIONS

This meta-analysis of RCTs provided evidence that local MSC injection is safe and efficacious for perianal fistulas in CD. In addition, this treatment has favorable long-term efficacy and safety profiles.