Darvadstrocel for the treatment of perianal fistulas in Crohn's disease

FiLaC® procedure for highly selected anal fistula patients: indications, safety and efficacy from an observational study at a tertiary referral center

BACKGROUND

the ideal clinical profile of patients or fistula features for fistula laser closure (FiLaC®) technique remain to be established. The aim of this study was to analyze clinical outcomes and the safety profile of FiLaC® in search for an ideal setting for this technique.

METHODS

a retrospective observational study was performed from a prospective database including all consecutive patients who underwent surgery for anal fistula (AF) with FiLaC® in the coloproctology unit of a tertiary referral center, between October 2015 and December 2021. The FiLaC® procedure was offered to AF patients who were considered to be at risk of fecal incontinence. Fistulas were described according to Parks' classification and categorized as complex or simple according to the American Gastroenterological Association (AGA) guidelines. Healing was defined by the closure of the internal and external openings for at least six months. Predictive factors of AF healing were investigated.

RESULTS

a total of 36 patients were included, with a mean age of 48 ± 13.9 years. Twenty patients (55.6 %) were male and 13 patients (36 %) had Crohn's disease (CD). Fourteen patients (38.8 %) had a complex fistula. The primary and secondary healing rates were 55.6 % and 91.7 %, respectively, during a median follow-up time of 12 months (IQR 7-29). No fecal continence impairment was registered in any case. The proportion of patients with primary healing was significantly higher in CD patients (76.9 % vs 43.5 %, p = 0.048).

CONCLUSIONS

FiLaC® is a sphincter-preserving procedure with an excellent safety profile and reasonable success rate despite of the strict patient selection. This technique may be attractive for patients with CD due to its higher primary healing rate.

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.

hucMSC-Ex Alleviates IBD-Associated Intestinal Fibrosis by Inhibiting ERK Phosphorylation in Intestinal Fibroblasts

Background

Intestinal fibrosis, one of the complications of inflammatory bowel disease (IBD), is associated with fistula and intestinal stricture formation. There are currently no treatments for fibrosis. Mesenchymal stem cell-derived exosomes have been proven to exert inhibitory and reversal effects in IBD and other organ fibrosis. In this study, we explored the role of human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Ex) in IBD-related fibrosis and its associated mechanism to provide new ideas for the prevention and treatment of IBD-related intestinal fibrosis.

Methods

We established a DSS-induced mouse IBD-related intestinal fibrosis model and observed the effect of hucMSC-Ex on the mouse model. We also used the TGF-induced human intestinal fibroblast CCD-18Co to observe the role of hucMSC-Ex in the proliferation, migration, and activation of intestinal fibroblasts. Having observed that the extracellular-signal-regulated kinase (ERK) pathway in intestinal fibrosis can be inhibited by hucMSC-Ex, we treated intestinal fibroblasts with an ERK inhibitor to emphasize the potential target of ERK phosphorylation in the treatment of IBD-associated intestinal fibrosis.

Results

In the animal model of IBD-related fibrosis, hucMSC-Ex alleviated inflammation-related fibrosis as evident in the thinning of the mice's intestinal wall and decreased expression of related molecules. Moreover, hucMSC-Ex inhibited TGF-β-induced proliferation, migration, and activation of human intestinal fibroblasts, and ERK phosphorylation played a key role in IBD-associated fibrosis. The inhibition of ERK decreased the expression of fibrosis-related indicators such as α-SMA, fibronectin, and collagen I.

Conclusion

hucMSC-Ex alleviates DSS-induced IBD-related intestinal fibrosis by inhibiting profibrotic molecules and intestinal fibroblast proliferation and migration by decreasing ERK phosphorylation.

Use of biologics for the management of Crohn's disease: IG-IBD clinical guidelines based on the GRADE methodology

A cure for Crohn's disease (CD), a chronic inflammatory disease of the gastrointestinal tract of unknown etiology, is not available, so patients require lifelong management to keep inflammation under control. The therapeutic armamentarium has expanded with approval of several biological drugs, including infliximab, adalimumab, vedolizumab and ustekinumab - monoclonal antibodies that target different inflammatory pathways - and darvadstrocel, a suspension of expanded human allogeneic, adipose-derived, mesenchymal stromal cells for the treatment of refractory complex perianal fistula. Notwithstanding existing practice guidelines on medical therapy for CD, the Italian Group for the Study of Inflammatory Bowel Disease felt the need to issue new guidelines focused on the use of biologics for managing the intestinal manifestations of CD and based on the GRADE methodology. This document presents recommendations regarding six clinical settings, from the induction to the maintenance of clinical remission, and from optimization and de-escalation of treatments to dealing with perianal CD and post-operative recurrence. The 19 evidence-based statements are supported by information on the quality of the evidence, agreement rate among panel members, and panel comments mainly based on evidence from real world studies.

A nanofiber-hydrogel composite improves tissue repair in a rat model of Crohn's disease perianal fistulas

Perianal fistulas (PAFs) represent a severe complication of Crohn's disease (CD). Despite the advent of biologic and small-molecule therapeutics for luminal disease, PAFs in CD (CD-PAF) are relatively resistant to treatment, with less than 50% responding to any therapy. We report an injectable, biodegradable, mechanically fragmented nanofiber-hydrogel composite (mfNHC) loaded with adipose-derived stem cells (ADSCs) for the treatment of fistulas in a rat model of CD-PAF. The ADSC-loaded mfNHC results in a higher degree of healing when compared to surgical treatment of fistulas, which is a standard treatment. The volume of fistulas treated with mfNHC is decreased sixfold compared to the surgical treatment control. Molecular studies reveal that utilization of mfNHC reduced local inflammation and improved tissue regeneration. This study demonstrates that ADSC-loaded mfNHC is a promising therapy for CD-PAF, and warrants further studies to advance mfNHC toward clinical translation.

Use of Mesenchymal Stem Cells in Crohn's Disease and Perianal Fistulas: A Narrative Review

Crohn's Disease (CD), which usually leads to anal fistulas among patients, is the most important inflammatory bowel disease that causes morbidity in many people around the world. This review article proposes using MSCs as a hopeful therapeutic strategy for CD and anal fistula treatment in both preclinical and clinical conditions. Finally, darvadstrocel, a cell-based medication to treat complex anal fistulas in adults, as the only European Medicines Agency (EMA)-approved product for the treatment of anal fistulas in CD is addressed. Although several common therapies, such as surgery and anti-tumor necrosis factor-alpha (TNF-α) drugs as well as a combination of these methods is used to improve this disease, however, due to the low effectiveness of these treatments, the use of new strategies with higher efficiency is still recommended. Cell therapy is among the new emerging therapeutic strategies that have attracted great attention from clinicians due to its unique capabilities. One of the most widely used cell sources administrated in cell therapy is mesenchymal stem cell (MSC). This review article will discuss preclinical and clinical studies about MSCs as a potent and promising therapeutic option in the treatment of CD and anal fistula.

Darvadstrocel for complex perianal fistulas in Japanese adults with Crohn's disease: a phase 3 study

BACKGROUND AND AIMS

Previous studies conducted in Europe suggested that 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. The aim of this study was to evaluate the efficacy and safety of darvadstrocel for the treatment of complex perianal fistulas in Japanese adults with Crohn's disease.

METHODS

This is a phase 3, open-label, single-arm study conducted at 9 sites in Japan. Adult patients with non-active or mildly active Crohn's disease and complex perianal fistulas received a single 24mL intralesional injection of darvadstrocel (120×10 6 cells). The primary endpoint was combined remission (clinically confirmed closure of all treated external openings that were draining at screening and absence of collections >2 cm [confirmed by magnetic resonance imaging] among treated fistulas) at Week 24.

RESULTS

Between March 6, 2019 and February 1, 2021, 22 patients received darvadstrocel and completed the 52-week follow-up. The proportion of patients achieving combined remission at Week 24 was 59.1% (95% CI, 38.5-79.6). The effect was maintained at Week 52, with 68.2% (95% CI, 48.7-87.6) of patients achieving combined remission. Treatment-related adverse events included: 1 (4.5%) patient with worsening of Crohn's disease and diarrhea and 1 (4.5%) patient with blood bilirubin increase. No new safety findings were identified in this study.

CONCLUSIONS

The efficacy and tolerability of darvadstrocel in Japanese adult patients with treatment-refractory complex perianal fistulas in Crohn's disease were similar to those observed in the previous European study.

Mechanism of Action of Mesenchymal Stem Cells (MSCs): impact of delivery method

INTRODUCTION

Mesenchymal stromal cells (MSCs; AKA mesenchymal stem cells) stimulate healing and reduce inflammation. Promising therapeutic responses are seen in many late-phase clinical trials, but others have not satisfied their primary endpoints, making translation of MSCs into clinical practice difficult. These inconsistencies may be related to the route of MSC delivery, lack of product optimization, or varying background therapies received in clinical trials over time.

AREAS COVERED

Here we discuss the different routes of MSC delivery, highlighting the proposed mechanism(s) of therapeutic action as well as potential safety concerns. PubMed search criteria used: MSC plus: local administration; routes of administration; delivery methods; mechanism of action; therapy in different diseases.

EXPERT OPINION

Direct injection of MSCs using a controlled local delivery approach appears to have benefits in certain disease states, but further studies are required to make definitive conclusions regarding the superiority of one delivery method over another.

Treatments for the amelioration of persistent factors in complex anal fistula

Anal fistulae are abnormal hollow connections between the wall of the anal canal and the perianal skin around the anus that have remained a burden on the medical sector for centuries. The complexity of this disease is attributed to a number of factors such as the degree of associated sphincter muscle, concomitant illnesses, existence of multiple fistulous tracts and the number of previous interventions. Persistence of a complex anal fistula can cause a decline in patient's physical quality of life as well as impact on the psychological status of patients who often suffer from anxiety and depression. Surgical intervention remains the gold standard for treatment, however; the risk of incontinence and high recurrence potential has led to interest into developing alternative treatment approaches such as the use of biologics, bioactives and biomaterials. One potential reason for these varied outcomes could be the multifactorial interplay between genetic, immune-related, environmental, and microbial persistence factors on tissue regeneration. Recent observations have proposed that adverse inflammatory mediators may contribute more than microbial factors. The moderate to high success rates of biotechnological advances (mesenchymal stem cells and biomaterial scaffolds) show promise as therapies for the amelioration of adverse persistent factors while facilitating a means to closing the fistula tract. The purpose of this review is to outline recent advances in biologics and combination therapies to treat persistent factors associated with complex anal fistula.

Research-Based Product Innovation to Address Critical Unmet Needs of Patients with Inflammatory Bowel Diseases

Despite progress in recent decades, patients with inflammatory bowel diseases face many critical unmet needs, demonstrating the limitations of available treatment options. Addressing these unmet needs will require interventions targeting multiple aspects of inflammatory bowel disease pathology, including disease drivers that are not targeted by available therapies. The vast majority of late-stage investigational therapies also focus primarily on a narrow range of fundamental mechanisms. Thus, there is a pressing need to advance to clinical stage differentiated investigational therapies directly targeting a broader range of key mechanistic drivers of inflammatory bowel diseases. In addition, innovations are critically needed to enable treatments to be tailored to the specific underlying abnormal biological pathways of patients; interventions with improved safety profiles; biomarkers to develop prognostic, predictive, and monitoring tests; novel devices for nonpharmacological approaches such as minimally invasive monitoring; and digital health technologies. To address these needs, the Crohn's & Colitis Foundation launched IBD Ventures, a venture philanthropy-funding mechanism, and IBD Innovate®, an innovative, product-focused scientific conference. This special IBD Innovate® supplement is a collection of articles reflecting the diverse and exciting research and development that is currently ongoing in the inflammatory bowel disease field to deliver innovative and differentiated products addressing critical unmet needs of patients. Here, we highlight the pipeline of new product opportunities currently advancing at the preclinical and early clinical development stages. We categorize and describe novel and differentiated potential product opportunities based on their potential to address the following critical unmet patient needs: (1) biomarkers for prognosis of disease course and prediction/monitoring of treatment response; (2) restoration of eubiosis; (3) restoration of barrier function and mucosal healing; (4) more effective and safer anti-inflammatories; (5) neuromodulatory and behavioral therapies; (6) management of disease complications; and (7) targeted drug delivery.

The Inflammatory Lung Microenvironment; a Key Mediator in MSC Licensing

Recent clinical trials of mesenchymal stromal cell (MSC) therapy for various inflammatory conditions have highlighted the significant benefit to patients who respond to MSC administration. Thus, there is strong interest in investigating MSC therapy in acute inflammatory lung conditions, such as acute respiratory distress syndrome (ARDS). Unfortunately, not all patients respond, and evidence now suggests that the differential disease microenvironment present across patients and sub-phenotypes of disease or across disease severities influences MSC licensing, function and therapeutic efficacy. Here, we discuss the importance of licensing MSCs and the need to better understand how the disease microenvironment influences MSC activation and therapeutic actions, in addition to the need for a patient-stratification approach.

Efficacy of stem cells therapy for Crohn's fistula: a meta-analysis and systematic review

BACKGROUND

Fistulas have puzzled us all the time and stem cell therapy for it is still in its infancy. We conducted a meta-analysis and systematic review to evaluate the efficacy of stem cells and its potential mechanisms in the management of Crohn's fistula.

METHODS

Electronic databases were searched comprehensively for studies reporting the efficacy and safety of stem cells in patients with any form of Crohn's fistula. A random-effects model was used, and all outcomes were calculated by SPSS 24.0.

RESULTS

Twenty-nine articles with 1252 patients were included. It showed that stem cell group had a higher rate of fistula healing compared to placebo group in patients of Crohn's fistula (61.75% vs 40.46%, OR 2.21, 95% CI 1.19 to 4.11, P < 0.05). 3 × 10⁷ cells/mL stem cell (SC) group had an advantage in fistula healing rate with 71.0% compared to other doses group of stem cells (RR 1.3, 95% CI 0.76 to 2.22). And the healing rates of patients with perianal and transsphincteric fistulas (77.95%, 76.41%) were higher than those with rectovaginal fistulas. It was an amazing phenomenon that CDAI and PDAI scores occurred an obviously transient rise with the use of stem cells after 1 month (both of P < 0.05), while they returned to the baseline level by giving stem cells 3 months later. Furthermore, the incidence rate of treatment-related adverse events in the stem cell group was significantly lower than in the placebo group (RR 0.58, 95% CI 0.30 to 1.14).

CONCLUSIONS

Our study has highlighted that stem cells was a promising method in the treatment of Crohn's fistula based on its higher efficacy and lower incidence of adverse events, especially ADSCs and Cx601. While it also needs more clinical and pre-clinical studies to strengthen evidences in the future.