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Cumulative Evidence That Mesenchymal Stem Cells Promote Healing of Perianal Fistulas of Patients With Crohn's Disease–Going From Bench to Bedside
EDITORIAL 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
Stem Cells in Perianal Crohn Disease: Cumulative Evidence and How to Go From the Bench to the Bedside See “Allogeneic bone marrow-derived mesenchymal stromal cells promote healing of refractory perianal fistulas in patients with Crohn’s disease,” by Molendijk I, Bonsing BA, Roelofs H, et al, on page 000.
I
n this month’s issue of Gastroenterology, Molendijk et al1 present their article entitled “Allogeneic Bone Marrow-derived Mesenchymal Stromal Cells Promote Healing of Refractory Perianal Fistulas in Patients with Crohn’s Disease.” The authors present a potential new treatment option: mesenchymal stromal cells (MSCs) for patients with refractory perianal Crohn’s disease (CD). Perianal fistulas are a common manifestation of CD affecting about 25% of patients2 and are a particularly destructive and morbid complication that frequently causes purulent drainage, pain, and sometimes fecal incontinence. The treatment options for Crohn’s perianal fistulas have evolved over time as our understanding of the disease process has improved. It is now standard of care to use a multidisciplinary approach using the gastroenterologist, surgeon, and advanced imaging techniques to optimize our available medical therapies and reduce morbidity. Despite the best medical and surgical options available to date, a significant proportion of our CD patients with perianal fistulas continue to suffer from persistent or recurrent perianal suppuration. In large, prospective trials using anti-tumor necrosis factor (TNF) antibodies in which fistula healing was measured, 60%–70% of the patients had persistent or recurrent drainage at the end of the study.3–5 Although each of these studies reported results that were better than placebo, it is clear that there is a large unmet need in this patient population. Numerous investigators have looked at various ways to address this unmet need, including employing advanced imaging to guide therapy, novel operative techniques, and new biologic agents, all of which hold promise for better outcomes for patients with perianal CD. As highlighted in the paper by Molendijk et al,1 stem cell (SC) therapy, although early in its development, may be a significant advancement to our current treatment paradigm, particularly for patients with refractory perianal fistulas. The rationale for using cell therapy to treat CD perianal fistulas is based in the pathophysiologic mechanisms that lead to the healing. In mammals, wound healing begins when a number of different cell types arrive at the wound area in a step known as the cellular phase. There are pathologic situations, such as a perianal fistula, in which this cell supply is deficient and wound healing may be delayed or incomplete. In the case of perianal fistulas associated
with CD, the problem becomes worse owing to the inflammatory basis of the disease that makes healing inefficient. SC transplantation provides a way of increasing the number of cells locally in this critical phase of healing. MSCs are potent anti-inflammatory and immunomodulatory agents6 that were initially described as a bone marrow–derived mononuclear cell population with a fibroblast-like morphology. Later, MSCs were described in many different tissues including fat and named adipose-derived SCs (ASCs).7 MSCs have been reported to be immune-active and are immuneprivileged cells. Although the mechanisms underlying the immunosuppressive effects of MSCs have not been defined clearly, basic research shows that MSCs modulate the function of different cells involved in the immune response.7,8 Based on these data, the use of SC to treat patients with perianal CD is a logical evolution for cell therapy taken from basic research on the immune regulatory and local anti-inflammatory effects of SC. Several trials have been conducted using SC to treat patients with CD perianal fistulas (Tables 1 and 2). Most trials are small, open-label studies in patients with refractory perianal fistulas and demonstrate benefit in this patient population. Initial trials involved harvesting ASCs and culturing autologous SC for later local injection. The first reports of SC treatment for perianal fistulas in CD were published nearly 10 years ago.9,10 A follow-up, phase II, multicenter, randomized study in 35 patients with complex perianal fistulas comparing ASC sandfibrin glue with fibrin glue alone was published in 2009.11 Fourteen patients in this trial had fistulas related to their CD. Of the 7 patients randomized to the ASCs and fibrin glue arm 5 of those 7 (71%) had complete cessation of fistula drainage compared with only 1 of the 7 patients (14%) treated with fibrin glue alone (P ¼ NS). In a subsequent study, of the 5 patients in the ASCs and fibrin glue group who had achieved closure, 2 (40%) had sustained closure at mean of approximately 3 years follow-up.12 The first report of autologous bone marrow-derived MSCs in the treatment of CD perianal fistulas was reported in 2011.13 The MSCs were delivered via local injection in 10 patients. A recent long-term follow-up study of the patients treated in this initial study reported that 37% of them maintained closure at 4 years.14 Similarly, in the current trial from Molendijk et al,1 85% of patients who received allogeneic MSCs improved. The largest study to date was an open-label study reported by Lee et al15 and used autologous ASCs in 42 patients with CD perianal fistulas. Sixty-seven percent (intention-to-treat analysis) of the patients treated had complete fistula closure. A recent follow-up report on the patients treated in this study demonstrated maintenance of fistula closure in 75% of the patients at year 2.16 Gastroenterology 2015;-:1–4
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Table 1.Published Clinical Trials and Large Ongoing Phase III Trials Using Stem Cells for the Treatment of Crohn’s Perianal Fistula Authors, Year
Study Design
Source of Cells
Results
Garcia-Olmo et al, 2005
Phase I clinical study (n ¼ 4)
ASC (autologous)
Garcia-Olmo et al, 200911
Open-label, multicenter, phase II study (n ¼ 14) Prospective study (n ¼ 10)
ASC þ fibrin glue (autologous) MSC (autologous) MSC (allogeneic) IV ASC þ fibrin glue (autologous) ASC (autologous) ASC (autologous)
Fistula closure in 82% PP, 67% ITT analysis
de la Portilla et al, 201319 Ciccocioppo et al, 201514 Cho et al, 201516
Open-label Phase II study (n ¼ 10) Retrospective follow-up of Garcia-Olmo phase II study (n ¼ 5) Open-label, multicenter, dose escalation phase I study (n ¼ 10) Open-label, multicenter, phase II study (n ¼ 42) Open-label pilot study (n ¼ 24) 5-year follow-up of 2011 study (n ¼ 10) 1-year follow-up from 2013 study
Reduction in CDAI, PDAI, and pain/ discharge PDAI scores Reduction in CDAI and fistula drainage 58% sustained fistula closure at end of follow-up by mean 3 years Healing in 50% receiving 2 107 cells/mL
ASC (allogeneic) MSC (autologous) ASC (autologous)
Garcia-Olmo et al, 201520
Retrospective, open label (n ¼ 3 with CD)
Complete closure: 56.3% 37% fistula relapse free 4 years later Complete closure maintained in 75% at 2 years ITT analysis Healing in 2/3 CD fistula patients
Molendijk et al, 20151
Double-blind, placebo-controlled study, phase II
10
Ciccocioppo et al, 201113 Mannon et al, 201117 Guadalajara et al, 201212 Cho et al, 201318 Lee et al, 201315
ASC (allogeneic and autologous) MSC (allogeneic)
Complete closure: 50% of patients 75% fistulas Fistula healing: 71% vs 14%
Healing up to 85%
NOTE. Source: Clinicaltrials.gov. ASCs, adipose-derived stem cells; CD, Crohn’s disease; CDAI, Crohn’s Disease Activity Index; ITT, intention to treat; IV, intravenous; MSCs, mesenchymal stem cells/mesenchymal stromal cells; PDAI, Pouchitis Disease Activity Index; PP, ---; SC, stem cells.
Because of time delay (w3 months from cell harvesting) and the complexity involved in autologous SC treatment, recent active trials largely involve the use of allogeneic SC banks. A large European randomized prospective multicenter study using intralesional allogeneic ASCs is ongoing (NCT01541579). Another phase III trial is being conducted using intravenously delivered allogeneic MSCs from bonemarrow (NCT00482092; Table 2). The most relevant practical issue is to choose the perfect candidate for cell therapy and their use in relationship to biological drugs. To date, trials of SC for patients with CD perianal fistulas have primarily included only patients who have been refractory to standard therapies. The initial trials required that patients discontinue immunomodulators and anti-TNF agents before entry into the trial. Because of the negative prognostic implications of having CD perianal fistulas and the need to control concomitant luminal disease, recent trials including the one presented in this journal1 have allowed patients to continue these medications if the dose has remained stable for several months. Anticipating best use in clinical practice, we envision that SC will be used as an adjuvant to standard therapy for patients with Crohn’s perianal fistulas. In other words, immunodulator and/or biologic therapy will be given to control luminal disease and perianal inflammation, with cell therapy used to close any residual fistulas. As we become more comfortable with cell therapy, it is feasible that we could use SC as part of the initial treatment plan in patients with CD perianal fistulas, but the bulk of the data currently available are in patients who have failed standard therapies.
Different SC types have been considered for preclinical and clinical applications in digestive tract diseases. Unfortunately, there is no such thing as an ideal SC showing optimal results for general use. To the date, only MSCs from bone marrow or fat have been used to treat CD perianal fistulas. The International Society for Cellular Therapy established 3 minimal criteria that MSCs must fulfil in vitro: adherence to plastic, specific surface antigen expression pattern (CD73þ CD90þ CD105þ CD34- CD45- CD11bCD14-CD19- CD79a HLA-DR-) and differentiation potential (osteogenic, chondrogenic, and adipogenic lineages).6 The question is which cell origin is better, bone marrow or adipose tissue? Because ex vivo–expanded MSCs are being used in the clinical setting, it is necessary to pay attention to the safety of the different cellular therapies. To achieve this aim, optimized culture conditions and isolation protocols are being established. Additionally, precise genetic stability studies have been developed to ensure the quality and biosafety of SCs in clinical practice. Both bone marrowderived and fat-derived cells meet this standard and have been used in the treatment of CD perianal fistulas. ASCs have the advantage of being able to be harvested in large quantities with minimal adverse effects through liposuction.11 Regarding the route of administration, is important to remark that only 1 study has used intravenous injection of allogeneic MSCs from bone marrow.17 Fistula healing was a secondary outcome in this trial.17 The remainder of the trials (2 with MSCs from bone marrow and the others from ASCs), have been designed to deliver the cells intralesionally (Table 1).
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Q3
179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238
270
208
Two arms: ASCs, placebo Three arms: placebo, high dose, and low dose
NOTE. Source: Clinicaltrials.gov. ASCs, adipose-derived stem cells; CD, Crohn’s disease.
CD (reduction in number of draining fistulas) NCT00482092
Osiris Therapeutics
USA, Australia, Canada, New Zealand
Allogeneic bone marrow
1200 million or 600 million cells infused in 4 visits
Active, not recruiting Active, not recruiting 12 107 Allogeneic fat Europe, Israel Tigenix Perianal fistula in CD NCT01541579
Intervention Model Status Cells Number Cells Source Location Sponsor Condition Trial Code
Table 2.Large Ongoing Phase III Trials Using Stem Cells for the Treatment of Crohn’s Perianal Fistula
239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297
Estimated Enrollment
EDITORIAL The dose of SC needed to optimize results has yet to be fully determined. The initial open-label trials used varying doses ranging from 3.5 106 up to 30 106 cells.10 Subsequently, investigators have tended to use increasing amounts of cells in an attempt to improve outcomes. In the trial from Lee et al,15 the investigators determined the dose of cells delivered based on the length of the tract. The average number of cells injected with the first injection (based on this formula) was 15.8 107. In the present study by Molendijk et al,1 patients were randomized to 3 different doses of cells (1 107, 3 107, 9 107) or placebo. Patients assigned to the 3 107 treatment dose had the best response rate. Indeed, those that were given the 9 107dose had a response rate numerically inferior to placebo. This outcome further highlights the need for additional work to better determine the most efficacious dose of SCs for these patients. To complete this editorial, we must make mention to the regulatory affairs. “Advanced therapy medicinal products” is a regulatory term used by the European Medicines Agency to designate a group of special biological therapies that are regulated under the medicines legislation. To date, SC in Europe can only be used under 2 regulatory statuses: approved clinical trial or compassionate use (refer to Regulation [EC] No 1394/2007 and Directive 2001/83/ EC). SC therapies in the United States are regulated by the Center for Biologic Evaluations and Research, a division of the US Food and Drug Administration (FDA). To date in the United States, the FDA has only approved minimally manipulated cell products for homologous use and has not approved any other SC medical products. Despite this, ASCs are being used in the treatment of everything from Parkinson’s disease to Alzheimer’s disease in clinics across the country. In recent FDA guidance on the subject, the agency recommended that ASCs be treated as a biologic drug requiring FDA approval before use in patients. Therefore, similar to the European regulations, SC should only be used in an approved clinical trial or as part of an approved compassionate use program. Anti-TNF therapies have revolutionized the treatment of IBD. However, about one-third of patients with perianal fistula are primary nonresponders to anti-TNF agents and a significant percentage of those that do respond either lose response or have persistent fistula drainage. There is a need for other agents with different mechanisms of action for these patients. SCs from fat or bone marrow have antiinflammatory and immune-regulatory properties and evident biologic effects in vitro and in experimental animal models. Additionally, SCs have demonstrated an excellent safety profile in several early phase clinical trials and hence should be considered as a potential therapeutic agents for refractory perianal fistulas in patients with CD as Molendijk et al1 have proposed. Despite the encouraging initial trials, the available information about long-term outcomes seems to be modest. Pending the results of phase III clinical trials, we suggest that different strategies to improve long-term therapeutic efficacy with SCs, including overexpression of CXCR4 receptor21 or engineering the cell surface with glycan22 may be needed. 3 EDI 5.4.0 DTD YGAST59998_proof 26 August 2015 3:06 am ce
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Most important, we have had a glimpse of how the evolution of SC research may provide a novel therapeutic option in CD. Investigators are converting cells into a new medical product that maybe useful to treat refractory perianal fistulas in patients with CD. Q4
12.
DAMIAN GARCIA-OLMO Department of Surgery (Fundacion Jimenez Diaz) Universidad Autonoma de Madrid Madrid, Spain
13.
DAVID A. SCHWARTZ Inflammatory Bowel Disease Center Department of Medicine Vanderbilt University Medical Center Nashville, Tennessee
14.
15.
References
Q2
1. Molendijk I, Bonsing BA, Roelofs H, et al. Allogeneic bone marrow-derived mesenchymal stromal cells promote healing of refractory perianal fistulas in patients with Crohn’s disease. Gastroenterology 2015. 000:000. 2. Schwartz DA, Loftus EV Jr, Tremaine WJ, et al. The natural history of fistulizing Crohn’s disease in Olmsted County, Minnesota. Gastroenterology 2002;122: 875–880. 3. Colombel JF, Schwartz DA, Sandborn WJ, et al. Adalimumab for the treatment of fistulas in patients with Crohn’s disease. Gut 2009;58:940–948. 4. Sands BS, Blank MA, Patel K, et al. Long-term treatment of fistulizing Crohn’s disease: response to infliximab in ACCENT II trials through 54 weeks. Clin Gastroenterol Hepatol 2004;2:912–920. 5. Schreiber S, Lawrance IC, Thomsen OØ, et al. Randomised clinical trial: certolizumab pegol for fistulas in Crohn’s disease - subgroup results from a placebocontrolled study. Aliment Pharmacol Ther 2011; 33:185–193. 6. García-Gómez I, Elvira G, Zapata AG, et al. Mesenchymal stem cells: biological properties and clinical applications. Expert Opin Biol Ther 2010;10:1453–1468. 7. González MA, Gonzalez-Rey E, Rico L, et al. Adiposederived mesenchymal stem cells alleviate experimental colitis by inhibiting inflammatory and autoimmune responses. Gastroenterology 2009;136:978–989. 8. Kim HS, Shin TH, Lee BC, et al. Human umbilical cord Blood mesenchymal stem cells reduce colitis in mice by activating NOD2 signaling to COX2. Gastroenterology 2013;145:1392–1403. 9. García-Olmo D, García-Arranz M, García LG, et al. Autologous stem cell transplantation for treatment of rectovaginal fistula in perianal Crohn’s disease: a new cell-based therapy. Int J Colorectal Dis 2003; 18:451–454. 10. García-Olmo D, García-Arranz M, Herreros D, et al. A phase I clinical trial of the treatment of Crohn’s fistula by adipose mesenchymal stem cell transplantation. Dis Colon Rectum 2005;48:1416–1423. 11. Garcia-Olmo D, Herreros D, Pascual I, et al. Expanded adipose-derived stem cells for the treatment of complex
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perianal fistula: a phase II clinical trial. Dis Colon Rectum 2009;52:79–86. Guadalajara H, Herreros D, De-La-Quintana P, et al. Long-term follow-up of patients undergoing adiposederived adult stem cell administration to treat complex perianal fistulas. Int J Colorectal Dis 2012;27:595–600. Ciccocioppo R, Bernardo ME, Sgarella A, et al. Autologous bone marrow-derived mesenchymal stromal cells in the treatment of fistulising Crohn’s disease. Gut 2011; 60:788–798. Ciccocioppo R, Gallia A, Sgarella A, et al. Long-term follow-up of Crohn disease fistulas after local injections of bone marrow-derived mesenchymal stem cells. Mayo Clin Proc 2015;90:747–755. Lee WY, Park KJ, Cho YB, et al. Autologous adipose tissue-derived stem cells treatment demonstrated favorable and sustainable therapeutic effect for Crohn’s fistula. Stem Cells 2013;31:2575–2581. Cho YB, Park KJ, Yoon SN, et al. Long-term results of adipose-derived stem cell therapy for the treatment of Crohn’s fistula. Stem Cells Transl Med 2015;4:532–537. Mannon PJ. Remestemcel-L: human mesenchymal stem cells as an emerging therapy for Crohn’s disease. Expert Opin Biol Ther 2011;11:1249–1256. Cho YB, Lee WY, Park KJ, et al. Autologous adipose tissue-derived stem cells for the treatment of Crohn’s fistula: a phase I clinical study. Cell Transplant 2013; 22:279–285. de la Portilla F, Alba F, García-Olmo D, et al. Expanded allogeneic adipose-derived stem cells (eASCs) for the treatment of complex perianal fistula in Crohn’s disease: results from a multicenter phase I/IIa clinical trial. Int J Colorectal Dis 2013;28:313–323. Garcia-Olmo D, Guadalajara H, Rubio-Perez I, et al. Recurrent anal fistulae: limited surgery supported by stem cells. World J Gastroenterol 2015;21: 3330–3336. Wynn RF, Hart CA, Corradi-Perini C, et al. A small proportion of mesenchymal stem cells strongly expresses functionally active CXCR4 receptor capable of promoting migration to bone marrow. Blood 2004;104:2643–2645. Sackstein R, Merzaban JS, Cain DW, et al. Ex vivo glycan engineering of CD44 programs human multipotent mesenchymal stromal cell trafficking to bone. Nat Med 2008;14:181–187.
Reprint requests Address requests for reprints to: Damian Garcia-Olmo, MD, Department of Surgery (Fundacion Jimenez Diaz), Universidad Autonoma de Madrid, Reyes Católicos 2, 28040 Madrid, Spain. e-mail: [email protected]. Conflicts of interest The authors have made the following disclosures: UAM and Cellerix SL/ Q1 Tygenix SL share patents rights in cell products. Damian García-Olmo is a member of the scientific advisory board of Tygenix. Damian García-Olmo is inventor in 2 patents related to cell products entitled “Identification and isolation of multipotent cells from non-osteochondral Mesenchymal tissue” (10157355957US) and “Use of adipose tissue derived stromal stem cells in treating fistula” (US11/167061). David A. Schwartz is a consultant for Tignix, Abbvie, Takeda, UCB and Janssen. Research funding from Abbvie, UCB. © 2015 by the AGA Institute 0016-5085/$36.00 http://dx.doi.org/10.1053/j.gastro.2015.08.038
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Stem Cells in Perianal Crohn Disease: Cumulative Evidence and How to Go From the Bench to the Bedside See “Allogeneic bone marrow-derived mesenchymal stromal cells promote healing of refractory perianal fistulas in patients with Crohn’s disease,” by Molendijk I, Bonsing BA, Roelofs H, et al, on page 000.
I
n this month’s issue of Gastroenterology, Molendijk et al1 present their article entitled “Allogeneic Bone Marrow-derived Mesenchymal Stromal Cells Promote Healing of Refractory Perianal Fistulas in Patients with Crohn’s Disease.” The authors present a potential new treatment option: mesenchymal stromal cells (MSCs) for patients with refractory perianal Crohn’s disease (CD). Perianal fistulas are a common manifestation of CD affecting about 25% of patients2 and are a particularly destructive and morbid complication that frequently causes purulent drainage, pain, and sometimes fecal incontinence. The treatment options for Crohn’s perianal fistulas have evolved over time as our understanding of the disease process has improved. It is now standard of care to use a multidisciplinary approach using the gastroenterologist, surgeon, and advanced imaging techniques to optimize our available medical therapies and reduce morbidity. Despite the best medical and surgical options available to date, a significant proportion of our CD patients with perianal fistulas continue to suffer from persistent or recurrent perianal suppuration. In large, prospective trials using anti-tumor necrosis factor (TNF) antibodies in which fistula healing was measured, 60%–70% of the patients had persistent or recurrent drainage at the end of the study.3–5 Although each of these studies reported results that were better than placebo, it is clear that there is a large unmet need in this patient population. Numerous investigators have looked at various ways to address this unmet need, including employing advanced imaging to guide therapy, novel operative techniques, and new biologic agents, all of which hold promise for better outcomes for patients with perianal CD. As highlighted in the paper by Molendijk et al,1 stem cell (SC) therapy, although early in its development, may be a significant advancement to our current treatment paradigm, particularly for patients with refractory perianal fistulas. The rationale for using cell therapy to treat CD perianal fistulas is based in the pathophysiologic mechanisms that lead to the healing. In mammals, wound healing begins when a number of different cell types arrive at the wound area in a step known as the cellular phase. There are pathologic situations, such as a perianal fistula, in which this cell supply is deficient and wound healing may be delayed or incomplete. In the case of perianal fistulas associated
with CD, the problem becomes worse owing to the inflammatory basis of the disease that makes healing inefficient. SC transplantation provides a way of increasing the number of cells locally in this critical phase of healing. MSCs are potent anti-inflammatory and immunomodulatory agents6 that were initially described as a bone marrow–derived mononuclear cell population with a fibroblast-like morphology. Later, MSCs were described in many different tissues including fat and named adipose-derived SCs (ASCs).7 MSCs have been reported to be immune-active and are immuneprivileged cells. Although the mechanisms underlying the immunosuppressive effects of MSCs have not been defined clearly, basic research shows that MSCs modulate the function of different cells involved in the immune response.7,8 Based on these data, the use of SC to treat patients with perianal CD is a logical evolution for cell therapy taken from basic research on the immune regulatory and local anti-inflammatory effects of SC. Several trials have been conducted using SC to treat patients with CD perianal fistulas (Tables 1 and 2). Most trials are small, open-label studies in patients with refractory perianal fistulas and demonstrate benefit in this patient population. Initial trials involved harvesting ASCs and culturing autologous SC for later local injection. The first reports of SC treatment for perianal fistulas in CD were published nearly 10 years ago.9,10 A follow-up, phase II, multicenter, randomized study in 35 patients with complex perianal fistulas comparing ASC sandfibrin glue with fibrin glue alone was published in 2009.11 Fourteen patients in this trial had fistulas related to their CD. Of the 7 patients randomized to the ASCs and fibrin glue arm 5 of those 7 (71%) had complete cessation of fistula drainage compared with only 1 of the 7 patients (14%) treated with fibrin glue alone (P ¼ NS). In a subsequent study, of the 5 patients in the ASCs and fibrin glue group who had achieved closure, 2 (40%) had sustained closure at mean of approximately 3 years follow-up.12 The first report of autologous bone marrow-derived MSCs in the treatment of CD perianal fistulas was reported in 2011.13 The MSCs were delivered via local injection in 10 patients. A recent long-term follow-up study of the patients treated in this initial study reported that 37% of them maintained closure at 4 years.14 Similarly, in the current trial from Molendijk et al,1 85% of patients who received allogeneic MSCs improved. The largest study to date was an open-label study reported by Lee et al15 and used autologous ASCs in 42 patients with CD perianal fistulas. Sixty-seven percent (intention-to-treat analysis) of the patients treated had complete fistula closure. A recent follow-up report on the patients treated in this study demonstrated maintenance of fistula closure in 75% of the patients at year 2.16 Gastroenterology 2015;-:1–4
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Table 1.Published Clinical Trials and Large Ongoing Phase III Trials Using Stem Cells for the Treatment of Crohn’s Perianal Fistula Authors, Year
Study Design
Source of Cells
Results
Garcia-Olmo et al, 2005
Phase I clinical study (n ¼ 4)
ASC (autologous)
Garcia-Olmo et al, 200911
Open-label, multicenter, phase II study (n ¼ 14) Prospective study (n ¼ 10)
ASC þ fibrin glue (autologous) MSC (autologous) MSC (allogeneic) IV ASC þ fibrin glue (autologous) ASC (autologous) ASC (autologous)
Fistula closure in 82% PP, 67% ITT analysis
de la Portilla et al, 201319 Ciccocioppo et al, 201514 Cho et al, 201516
Open-label Phase II study (n ¼ 10) Retrospective follow-up of Garcia-Olmo phase II study (n ¼ 5) Open-label, multicenter, dose escalation phase I study (n ¼ 10) Open-label, multicenter, phase II study (n ¼ 42) Open-label pilot study (n ¼ 24) 5-year follow-up of 2011 study (n ¼ 10) 1-year follow-up from 2013 study
Reduction in CDAI, PDAI, and pain/ discharge PDAI scores Reduction in CDAI and fistula drainage 58% sustained fistula closure at end of follow-up by mean 3 years Healing in 50% receiving 2 107 cells/mL
ASC (allogeneic) MSC (autologous) ASC (autologous)
Garcia-Olmo et al, 201520
Retrospective, open label (n ¼ 3 with CD)
Complete closure: 56.3% 37% fistula relapse free 4 years later Complete closure maintained in 75% at 2 years ITT analysis Healing in 2/3 CD fistula patients
Molendijk et al, 20151
Double-blind, placebo-controlled study, phase II
10
Ciccocioppo et al, 201113 Mannon et al, 201117 Guadalajara et al, 201212 Cho et al, 201318 Lee et al, 201315
ASC (allogeneic and autologous) MSC (allogeneic)
Complete closure: 50% of patients 75% fistulas Fistula healing: 71% vs 14%
Healing up to 85%
NOTE. Source: Clinicaltrials.gov. ASCs, adipose-derived stem cells; CD, Crohn’s disease; CDAI, Crohn’s Disease Activity Index; ITT, intention to treat; IV, intravenous; MSCs, mesenchymal stem cells/mesenchymal stromal cells; PDAI, Pouchitis Disease Activity Index; PP, ---; SC, stem cells.
Because of time delay (w3 months from cell harvesting) and the complexity involved in autologous SC treatment, recent active trials largely involve the use of allogeneic SC banks. A large European randomized prospective multicenter study using intralesional allogeneic ASCs is ongoing (NCT01541579). Another phase III trial is being conducted using intravenously delivered allogeneic MSCs from bonemarrow (NCT00482092; Table 2). The most relevant practical issue is to choose the perfect candidate for cell therapy and their use in relationship to biological drugs. To date, trials of SC for patients with CD perianal fistulas have primarily included only patients who have been refractory to standard therapies. The initial trials required that patients discontinue immunomodulators and anti-TNF agents before entry into the trial. Because of the negative prognostic implications of having CD perianal fistulas and the need to control concomitant luminal disease, recent trials including the one presented in this journal1 have allowed patients to continue these medications if the dose has remained stable for several months. Anticipating best use in clinical practice, we envision that SC will be used as an adjuvant to standard therapy for patients with Crohn’s perianal fistulas. In other words, immunodulator and/or biologic therapy will be given to control luminal disease and perianal inflammation, with cell therapy used to close any residual fistulas. As we become more comfortable with cell therapy, it is feasible that we could use SC as part of the initial treatment plan in patients with CD perianal fistulas, but the bulk of the data currently available are in patients who have failed standard therapies.
Different SC types have been considered for preclinical and clinical applications in digestive tract diseases. Unfortunately, there is no such thing as an ideal SC showing optimal results for general use. To the date, only MSCs from bone marrow or fat have been used to treat CD perianal fistulas. The International Society for Cellular Therapy established 3 minimal criteria that MSCs must fulfil in vitro: adherence to plastic, specific surface antigen expression pattern (CD73þ CD90þ CD105þ CD34- CD45- CD11bCD14-CD19- CD79a HLA-DR-) and differentiation potential (osteogenic, chondrogenic, and adipogenic lineages).6 The question is which cell origin is better, bone marrow or adipose tissue? Because ex vivo–expanded MSCs are being used in the clinical setting, it is necessary to pay attention to the safety of the different cellular therapies. To achieve this aim, optimized culture conditions and isolation protocols are being established. Additionally, precise genetic stability studies have been developed to ensure the quality and biosafety of SCs in clinical practice. Both bone marrowderived and fat-derived cells meet this standard and have been used in the treatment of CD perianal fistulas. ASCs have the advantage of being able to be harvested in large quantities with minimal adverse effects through liposuction.11 Regarding the route of administration, is important to remark that only 1 study has used intravenous injection of allogeneic MSCs from bone marrow.17 Fistula healing was a secondary outcome in this trial.17 The remainder of the trials (2 with MSCs from bone marrow and the others from ASCs), have been designed to deliver the cells intralesionally (Table 1).
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Q3
179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238
270
208
Two arms: ASCs, placebo Three arms: placebo, high dose, and low dose
NOTE. Source: Clinicaltrials.gov. ASCs, adipose-derived stem cells; CD, Crohn’s disease.
CD (reduction in number of draining fistulas) NCT00482092
Osiris Therapeutics
USA, Australia, Canada, New Zealand
Allogeneic bone marrow
1200 million or 600 million cells infused in 4 visits
Active, not recruiting Active, not recruiting 12 107 Allogeneic fat Europe, Israel Tigenix Perianal fistula in CD NCT01541579
Intervention Model Status Cells Number Cells Source Location Sponsor Condition Trial Code
Table 2.Large Ongoing Phase III Trials Using Stem Cells for the Treatment of Crohn’s Perianal Fistula
239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297
Estimated Enrollment
EDITORIAL The dose of SC needed to optimize results has yet to be fully determined. The initial open-label trials used varying doses ranging from 3.5 106 up to 30 106 cells.10 Subsequently, investigators have tended to use increasing amounts of cells in an attempt to improve outcomes. In the trial from Lee et al,15 the investigators determined the dose of cells delivered based on the length of the tract. The average number of cells injected with the first injection (based on this formula) was 15.8 107. In the present study by Molendijk et al,1 patients were randomized to 3 different doses of cells (1 107, 3 107, 9 107) or placebo. Patients assigned to the 3 107 treatment dose had the best response rate. Indeed, those that were given the 9 107dose had a response rate numerically inferior to placebo. This outcome further highlights the need for additional work to better determine the most efficacious dose of SCs for these patients. To complete this editorial, we must make mention to the regulatory affairs. “Advanced therapy medicinal products” is a regulatory term used by the European Medicines Agency to designate a group of special biological therapies that are regulated under the medicines legislation. To date, SC in Europe can only be used under 2 regulatory statuses: approved clinical trial or compassionate use (refer to Regulation [EC] No 1394/2007 and Directive 2001/83/ EC). SC therapies in the United States are regulated by the Center for Biologic Evaluations and Research, a division of the US Food and Drug Administration (FDA). To date in the United States, the FDA has only approved minimally manipulated cell products for homologous use and has not approved any other SC medical products. Despite this, ASCs are being used in the treatment of everything from Parkinson’s disease to Alzheimer’s disease in clinics across the country. In recent FDA guidance on the subject, the agency recommended that ASCs be treated as a biologic drug requiring FDA approval before use in patients. Therefore, similar to the European regulations, SC should only be used in an approved clinical trial or as part of an approved compassionate use program. Anti-TNF therapies have revolutionized the treatment of IBD. However, about one-third of patients with perianal fistula are primary nonresponders to anti-TNF agents and a significant percentage of those that do respond either lose response or have persistent fistula drainage. There is a need for other agents with different mechanisms of action for these patients. SCs from fat or bone marrow have antiinflammatory and immune-regulatory properties and evident biologic effects in vitro and in experimental animal models. Additionally, SCs have demonstrated an excellent safety profile in several early phase clinical trials and hence should be considered as a potential therapeutic agents for refractory perianal fistulas in patients with CD as Molendijk et al1 have proposed. Despite the encouraging initial trials, the available information about long-term outcomes seems to be modest. Pending the results of phase III clinical trials, we suggest that different strategies to improve long-term therapeutic efficacy with SCs, including overexpression of CXCR4 receptor21 or engineering the cell surface with glycan22 may be needed. 3 EDI 5.4.0 DTD YGAST59998_proof 26 August 2015 3:06 am ce
298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357
EDITORIAL 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416
Most important, we have had a glimpse of how the evolution of SC research may provide a novel therapeutic option in CD. Investigators are converting cells into a new medical product that maybe useful to treat refractory perianal fistulas in patients with CD. Q4
12.
DAMIAN GARCIA-OLMO Department of Surgery (Fundacion Jimenez Diaz) Universidad Autonoma de Madrid Madrid, Spain
13.
DAVID A. SCHWARTZ Inflammatory Bowel Disease Center Department of Medicine Vanderbilt University Medical Center Nashville, Tennessee
14.
15.
References
Q2
1. Molendijk I, Bonsing BA, Roelofs H, et al. Allogeneic bone marrow-derived mesenchymal stromal cells promote healing of refractory perianal fistulas in patients with Crohn’s disease. Gastroenterology 2015. 000:000. 2. Schwartz DA, Loftus EV Jr, Tremaine WJ, et al. The natural history of fistulizing Crohn’s disease in Olmsted County, Minnesota. Gastroenterology 2002;122: 875–880. 3. Colombel JF, Schwartz DA, Sandborn WJ, et al. Adalimumab for the treatment of fistulas in patients with Crohn’s disease. Gut 2009;58:940–948. 4. Sands BS, Blank MA, Patel K, et al. Long-term treatment of fistulizing Crohn’s disease: response to infliximab in ACCENT II trials through 54 weeks. Clin Gastroenterol Hepatol 2004;2:912–920. 5. Schreiber S, Lawrance IC, Thomsen OØ, et al. Randomised clinical trial: certolizumab pegol for fistulas in Crohn’s disease - subgroup results from a placebocontrolled study. Aliment Pharmacol Ther 2011; 33:185–193. 6. García-Gómez I, Elvira G, Zapata AG, et al. Mesenchymal stem cells: biological properties and clinical applications. Expert Opin Biol Ther 2010;10:1453–1468. 7. González MA, Gonzalez-Rey E, Rico L, et al. Adiposederived mesenchymal stem cells alleviate experimental colitis by inhibiting inflammatory and autoimmune responses. Gastroenterology 2009;136:978–989. 8. Kim HS, Shin TH, Lee BC, et al. Human umbilical cord Blood mesenchymal stem cells reduce colitis in mice by activating NOD2 signaling to COX2. Gastroenterology 2013;145:1392–1403. 9. García-Olmo D, García-Arranz M, García LG, et al. Autologous stem cell transplantation for treatment of rectovaginal fistula in perianal Crohn’s disease: a new cell-based therapy. Int J Colorectal Dis 2003; 18:451–454. 10. García-Olmo D, García-Arranz M, Herreros D, et al. A phase I clinical trial of the treatment of Crohn’s fistula by adipose mesenchymal stem cell transplantation. Dis Colon Rectum 2005;48:1416–1423. 11. Garcia-Olmo D, Herreros D, Pascual I, et al. Expanded adipose-derived stem cells for the treatment of complex
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Reprint requests Address requests for reprints to: Damian Garcia-Olmo, MD, Department of Surgery (Fundacion Jimenez Diaz), Universidad Autonoma de Madrid, Reyes Católicos 2, 28040 Madrid, Spain. e-mail: [email protected]. Conflicts of interest The authors have made the following disclosures: UAM and Cellerix SL/ Q1 Tygenix SL share patents rights in cell products. Damian García-Olmo is a member of the scientific advisory board of Tygenix. Damian García-Olmo is inventor in 2 patents related to cell products entitled “Identification and isolation of multipotent cells from non-osteochondral Mesenchymal tissue” (10157355957US) and “Use of adipose tissue derived stromal stem cells in treating fistula” (US11/167061). David A. Schwartz is a consultant for Tignix, Abbvie, Takeda, UCB and Janssen. Research funding from Abbvie, UCB. © 2015 by the AGA Institute 0016-5085/$36.00 http://dx.doi.org/10.1053/j.gastro.2015.08.038
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