6-Mercaptopurine is effective in Crohn's disease without concomitant steroids

Stem Cell Therapies for Inflammatory Bowel Disease

PURPOSE OF REVIEW

Stem cell therapies have demonstrated safety and efficacy in the treatment of perianal Crohn's disease as compared to conventional therapy. Thus, an understanding of their place in the treatment algorithm for inflammatory bowel disease has become imperative as we move into an era of regenerative medicine.

RECENT FINDINGS

There have now been over a dozen clinical trials highlighting stem cells as a useful therapeutic in Crohn's disease. Due to the success in the local treatment for perianal Crohn's disease, investigation is continuing in the space of targeted systemic delivery for the treatment of luminal disease. As we increase the number of patients treated in clinical trials, it is imperative to define the optimal cell donor, optimize treatment dosing and retreatment protocols, and understand methods for safely targeting and treating intraluminal disease.

Immune rebalancing by oral immunotherapy: A novel method for getting the immune system back on track

Immune modulating treatments are often associated with immune suppression or an opposing anti-inflammatory paradigm. As such, there is a risk of exposing patients to infections and malignancies. Contrarily, eliciting only mild immune modulation can be insufficient for alleviating immune-mediated damage. Oral immunotherapy is a novel approach that uses the inherent ability of the gut immune system to generate signals that specifically suppress inflammation at affected sites, without inducing generalized immune suppression. Oral immunotherapy is being developed as a method to rebalance systemic immunity and restore balance, getting it back on track, rather than pushing the immune response too much or too little in opposing directions. Here, I review recent preclinical and clinical data examining the technique and describe its primary advantages.

A Systematic Review and Meta-analysis of Mesenchymal Stem Cell Injections for the Treatment of Perianal Crohn's Disease: Progress Made and Future Directions

BACKGROUND

There has been a surge in clinical trials studying the safety and efficacy of mesenchymal stem cells for the treatment of perianal Crohn's disease.

OBJECTIVE

The purpose of this work was to systematically review the literature to determine safety and efficacy of mesenchymal stem cells for the treatment of refractory perianal Crohn's disease.

DATA SOURCES

Sources included PubMed, Cochrane Library Central Register of Controlled Trials, and Embase.

STUDY SELECTION

Studies that reported safety and/or efficacy of mesenchymal stem cells for the treatment of perianal Crohn's disease were included. Two independent assessors reviewed eligible articles.

INTERVENTION

The study intervention was delivery of mesenchymal stem cells to treat perianal Crohn's disease.

MAIN OUTCOMES MEASURES

Safety and efficacy of mesenchymal stem cells used to treat perianal Crohn's disease were measured.

RESULTS

Eleven studies met the inclusion criteria and were included in the systematic review. Three trials with a comparison arm were included in the meta-analysis. There were no significant increases in adverse events (OR = 1.07 (95% CI, 0.61-1.89); p = 0.81) or serious adverse events (OR = 0.53 (95% CI, 0.28-0.98); p = 0.04) in patients treated with mesenchymal stem cells. Mesenchymal stem cells were associated with improved healing as compared with control subjects at primary end points of 6 to 24 weeks (OR = 3.06 (95% CI, 1.05-8.90); p = 0.04) and 24 to 52 weeks (OR = 2.37 (95% CI, 0.90-6.25); p = 0.08).

LIMITATIONS

The study was limited by its multiple centers and heterogeneity in the study inclusion criteria, mesenchymal stem cell origin, dose and frequency of delivery, use of scaffolding, and definition and time point of fistula healing.

CONCLUSIONS

Although there have been only 3 trials conducted with control arms, existing data demonstrate improved efficacy and no increase in adverse or serious adverse events with mesenchymal stem cells as compared with control subjects for the treatment of perianal Crohn's disease.

Long-term Efficacy and Safety of Stem Cell Therapy (Cx601) for Complex Perianal Fistulas in Patients With Crohn's Disease

BACKGROUND & AIMS

Therapies for perianal fistulas in patients with Crohn's disease are often ineffective in producing long-term healing. We performed a randomized placebo-controlled trial to determine the long-term efficacy and safety of a single local administration of allogeneic expanded adipose-derived stem cells (Cx601) in patients with Crohn's disease and perianal fistulas.

METHODS

We performed a double-blind study at 49 hospitals in Europe and Israel, comprising 212 patients with Crohn's disease and treatment-refractory, draining, complex perianal fistulas. Patients were randomly assigned (1:1) to groups given a single local injection of 120 million Cx601 cells or placebo (control), in addition to the standard of care. Efficacy endpoints evaluated in the modified intention-to-treat population (randomly assigned, treated, and with 1 or more post-baseline efficacy assessment) at week 52 included combined remission (closure of all treated external openings draining at baseline with absence of collections >2 cm, confirmed by magnetic resonance imaging) and clinical remission (absence of draining fistulas).

RESULTS

The study's primary endpoint, at week 24, was previously reported (combined remission in 51.5% of patients given Cx601 vs 35.6% of controls, for a difference of 15.8 percentage points; 97.5% confidence interval [CI] 0.5-31.2; P = .021). At week 52, a significantly greater proportion of patients given Cx601 achieved combined remission (56.3%) vs controls (38.6%) (a difference of 17.7 percentage points; 95% CI 4.2-31.2; P = .010), and clinical remission (59.2% vs 41.6% of controls, for a difference of 17.6 percentage points; 95% CI 4.1-31.1; P = .013). Safety was maintained throughout week 52; adverse events occurred in 76.7% of patients in the Cx601 group and 72.5% of patients in the control group.

CONCLUSION

In a phase 3 trial of patients with Crohn's disease and treatment-refractory complex perianal fistulas, we found Cx601 to be safe and effective in closing external openings, compared with placebo, after 1 year. ClinicalTrials.gov no: NCT01541579.

Mesenchymal Stem Cell Injections for the Treatment of Perianal Crohn's Disease: What We Have Accomplished and What We Still Need to Do

Perianal Crohn's disease [CD] is found in a quarter of patients with CD and remains notoriously difficult to treat. Several medical and surgical therapies are available. However, none is particularly effective nor reliably provides sustained remission. In addition, surgical intervention is complicated by poor healing and the potential for incontinence. Mesenchymal stem cell-based therapies provide a promising treatment alternative for perianal CD, with demonstrated safety, improved efficacy, and a decreased side effect profile. Several phase I, II, and now III randomised controlled trials have now reported safety and efficacy in treating perianal CD. The aim of this review is to discusses the outcomes of conventional treatment approaches, outcomes of mesenchymal stem cell therapies, considerations specific to stem cell-based therapies, and future directions for research.

Expanded allogeneic adipose-derived mesenchymal stem cells (Cx601) for complex perianal fistulas in Crohn's disease: a phase 3 randomised, double-blind controlled trial

BACKGROUND

Complex perianal fistulas in Crohn's disease are challenging to treat. Allogeneic, expanded, adipose-derived stem cells (Cx601) are a promising new therapeutic approach. We aimed to assess the safety and efficacy of Cx601 for treatment-refractory complex perianal fistulas in patients with Crohn's disease.

METHODS

We did this randomised, double-blind, parallel-group, placebo-controlled study at 49 hospitals in seven European countries and Israel from July 6, 2012, to July 27, 2015. Adult patients (≥18 years) with Crohn's disease and treatment-refractory, draining complex perianal fistulas were randomly assigned (1:1) using a pre-established randomisation list to a single intralesional injection of 120 million Cx601 cells or 24 mL saline solution (placebo), with stratification according to concomitant baseline treatment. Treatment was administered by an unmasked surgeon, with a masked gastroenterologist and radiologist assessing the therapeutic effect. The primary endpoint was combined remission at week 24 (ie, clinical assessment of closure of all treated external openings that were draining at baseline, and absence of collections >2 cm of the treated perianal fistulas confirmed by masked central MRI). Efficacy was assessed in the intention-to-treat (ITT) and modified ITT populations; safety was assessed in the safety population. This study is registered with ClinicalTrials.gov, number NCT01541579.

FINDINGS

212 patients were randomly assigned: 107 to Cx601 and 105 to placebo. A significantly greater proportion of patients treated with Cx601 versus placebo achieved combined remission in the ITT (53 of 107 [50%] vs 36 of 105 [34%]; difference 15·2%, 97·5% CI 0·2-30·3; p=0·024) and modified ITT populations (53 of 103 [51%] vs 36 of 101 [36%]; 15·8%, 0·5-31·2; p=0·021). 18 (17%) of 103 patients in the Cx601 group versus 30 (29%) of 103 in the placebo group experienced treatment-related adverse events, the most common of which were anal abscess (six in the Cx601 group vs nine in the placebo group) and proctalgia (five vs nine).

INTERPRETATION

Cx601 is an effective and safe treatment for complex perianal fistulas in patients with Crohn's disease who did not respond to conventional or biological treatments, or both.

FUNDING

TiGenix.

Effect of long-term low-dose prednisone on height velocity and disease activity in pediatric and adolescent patients with Crohn disease

OBJECTIVES

To determine whether long-term low-dose prednisone (LTLDP) therapy has a decelerating effect on growth velocity and whether this therapy is effective in the maintenance of remission in the subgroup of pediatric patients with Crohn disease (CD) who had previously experienced flares on more than 1 occasion when prednisone was discontinued.

PATIENTS AND METHODS

A retrospective chart review of patients was done. Our sample consisted of patients 6 to 17 years of age with CD who had received uninterrupted prednisone at an average daily dose of 0.1 to 0.4 mg x kg(-1) x day(-1) for at least 8 weeks. Their heights were plotted on sex-appropriate growth charts at 4 time points: 1 year before LTLDP, at therapy onset, at therapy discontinuation, and 1 year after therapy was discontinued. The height velocities (HVs) were compared with the normal HV established by Tanner. The disease activities of 2 groups were compared: LTLDP plus azathioprine/6-mercaptopurine (AZA/6-MP) and LTLDP alone.

RESULTS

One hundred two patients were included. The mean age of our sample was 13.7 +/- 2.7 years (standard deviation). The mean dose of prednisone dose was 0.18 +/- 0.07 mg x kg(-1) x day(-1)), for a mean duration of therapy of 14.4 +/- 7.2 months. Throughout the study, 78% of patients had normal HV. Growth deceleration was seen in 19% of patients with prior normal growth. Of this group, 31% had "catch-up" growth 1 year after prednisone was discontinued; the remaining 69% did not. Catch-up growth was more likely in patients who had reached the expected age peak HV, which is defined as 12.5 years for girls and 13.5 years for boys (P = 0.04). In addition, 6 patients reached the peak HV after LTLDP discontinuation; 13 did not. We found no difference in the maintenance of remission rate between the compared groups.

CONCLUSIONS

A minority of our study population had growth deceleration. Age was an important factor for subsequent catch-up growth. LTLDP efficacy to maintain remission was not different from that of LTLDP plus AZA/6-MP; differences in concomitant therapies (eg, antibiotics, infliximab) between the 2 groups were not statistically significant.

Liver injury in inflammatory bowel disease: long-term follow-up study of 786 patients

BACKGROUND

The aim of the study was to evaluate the incidence of abnormality of liver tests (LTs) or hepatotoxicity in a large group of inflammatory bowel disease (IBD) patients and, specifically, to assess the incidence of azathioprine (AZA)/mercaptopurine (MP)-induced liver injury in a long-term follow-up study.

METHODS

All consecutive IBD patients followed for at least 5 years were included in this retrospective study. LTs including alanine transaminase, aspartate transaminase, alkaline phosphatase, gamma-glutamyl transferase, and bilirubin were periodically monitored. "Abnormality-of-LTs" was defined as LTs between N (upper limit of the normal range) and 2 N, and "liver injury/hepatotoxicity" as LTs>2 N.

RESULTS

A total of 786 patients were included, and 138 received AZA/MP; 120 patients (15%) and 39 (5%) presented abnormality of LTs or hepatotoxicity, respectively, during follow-up. The most frequent explanations were AZA/MP treatment and fatty liver disease. Among AZA/MP-treated patients (690 patient-years follow-up) the incidence of abnormal LTs and hepatotoxicity was, respectively, 7.1% and 2.6% per patient-year. Most patients spontaneously normalized LTs despite maintaining AZA/MP. These drugs were withdrawn due to hepatotoxicity (LTs>5 N and lack of decrease despite 50% dose reduction) in 3.6% of the patients and all of them normalized LTs.

CONCLUSIONS

In IBD patients, AZA or MP treatment induces abnormality of LTs in a relatively high proportion of the cases, but the development of true hepatotoxicity/liver injury is exceptional. Moreover, most of the cases of thiopurine-induced hepatotoxicity in IBD patients are mild, and the abnormalities in LTs spontaneously return to normal values despite AZA/MP being maintained, therapy withdrawal being necessary in only approximately 4% of the patients.

Thiopurine-induced liver injury in patients with inflammatory bowel disease: a systematic review

The mean prevalence of azathioprine (AZA) or 6-mercaptopurine (MP)-induced liver injury in patients with inflammatory bowel disease was approximately 3%, and the mean annual drug-induced liver disorder rate was only 1.4%. However, this low figure calculated from retrospective studies contrasts with a much higher incidence (>10%) reported by a prospective study. Thiopurine-induced hepatotoxicity can be grouped into three syndromes: hypersensitivity, idiosyncratic cholestatic reaction, and endothelial cell injury (with resultant raised portal pressures, veno-occlusive disease, or peliosis hepatis). A small percentage of patients present with a slight elevation of liver tests (LTs) that do not have clinical implications and LTs return to normal values during the follow-up, indicating that it is not always necessary to adjust the dose of the immunomodulator. However, when abnormalities in LTs are more marked, the dose of AZA/MP may be reduced 50%, with posterior clinical and analytical controls. With this strategy, LTs frequently normalize spontaneously, and the initial AZA/MP dose may be cautiously prescribed again. Thiopurines may induce an unusual severe cholestatic jaundice that may not regress but even progress despite thiopurine withdrawal. Therefore, these drugs should be completely withdrawn, and not only tapered, in those patients presenting clinically significant jaundice. Despite a lack of evidence that monitoring of LTs is necessary in patients receiving AZA/MP, routinely performed laboratory controls including LTs seem recommendable. However, the optimal monitoring schedule remains to be established. As long-term hepatotoxicity seems to be an unpredictable and potentially severe adverse drug reaction of 6-thioguanine, this drug should not be administered outside a clinical trial setting. (Am J Gastroenterol 2007;102:1518-527).

Recent advances in the etiology and treatment of inflammatory bowel disease

Crohn's disease and ulcerative colitis, together comprising the inflammatory bowel diseases, currently affect up to 2 million people in the western developed countries. The pathogenesis of the disease is a complex one in which genetic, immunogenic, microbial and environmental factors contribute to the etiology of the disease. Recent advances in understanding the molecular mechanisms that determine this complex entity have provided insight for promising new therapies.

Effect of systemic corticosteroid therapy on risk for intra-abdominal or pelvic abscess in non-operated Crohn's disease

BACKGROUND & AIMS

Systemic corticosteroid therapy increases risk of postoperative sepsis in Crohn's disease. This study investigates its effect on risk for sepsis in non-operated patients.

METHODS

A retrospective case-control study was performed in 432 patients with Crohn's disease (the 94% of our database for whom adequate documentation could be retrieved). Two analyses were performed. The first tested the hypothesis that patients with perforating Crohn's disease (n = 86) were more likely to develop intra-abdominal or pelvic abscess (n = 29) if they had received systemic corticosteroids during the previous 3 months. The second analysis, confined to interventions since 1998, tested the hypothesis that corticosteroid therapy was more common during the 3 months before presentation with intra-abdominal or pelvic abscess (n = 12) than during the 3 months after presentation with a relapse of nonperforating disease (n = 24 consecutive patients). In both analyses adjustment was made for any other significant variable.

RESULTS

Systemic corticosteroid therapy was associated with an adjusted odds ratio (OR) for intra-abdominal or pelvic abscess of 9.03 (95% confidence interval [CI], 2.40-33.98) in patients with perforating Crohn's disease. Patients receiving prednisolone > or = 20 mg per day had an OR of 2.81 (95% CI, 0.99-7.99) for abscess compared with those receiving a lower dose. In patients with relapsed active disease, corticosteroid therapy was associated with an unadjusted OR of 9.31 (95% CI, 1.03-83.91) for intra-abdominal or pelvic abscess. Neither smoking nor azathioprine usage was associated with increased risk for abscess.

CONCLUSIONS

Systemic corticosteroid therapy for Crohn's disease is associated with increased risk for intra-abdominal or pelvic abscess.

Incidence, risk factors and clinical course of thiopurine-induced liver injury in patients with inflammatory bowel disease

BACKGROUND

The incidence of thiopurine-induced hepatotoxicity in patients with inflammatory bowel disease varies in different studies.

AIMS

To assess the rate of thiopurine-induced liver toxicity in patients with inflammatory bowel disease; to determine the predictive factors and to characterize its clinical course and management.

METHODS

A cohort of 161 patients was prospectively followed for a median of 271 days. Hepatotoxicity was established when alanine transaminase or alkaline phosphatase plasma levels were greater than twice the upper normal limit.

RESULTS

Abnormal liver function was detected in 21 patients (13%; 95% CI: 7-18). Hepatotoxicity occurred in 16 patients (10%; 95% CI: 6-16) after a median of 85 days. In five cases, treatment was withdrawn due to hepatotoxicity. Use of corticosteroids was associated with hepatotoxicity (OR: 4.94; 95% CI: 1.01-23.98) with antitumour necrosis factor concomitant therapy showing a protective role (OR: 0.3; 95% CI: 0.1-3.1). gamma-Glutamyl transferase plasma levels at the onset of hepatotoxicity showed the best predictive value for treatment withdrawal (area under the receiver operating characteristic curve: 0.95).

CONCLUSIONS

The incidence of hepatotoxicity in inflammatory bowel disease patients receiving thiopurines is relevant, mainly in patients co-treated with corticosteroids. gamma-Glutamyl transferase plasma level is a useful biomarker in therapy withdrawal prediction.