FROM STEM CELLS TRANSLATIONAL MEDICINE
Three-quarters of Crohn’s fistula patients who were treated with one or two doses of autologous mesenchymal stem cells derived from adipose tissue achieved complete closure at 2 years of follow-up, a retrospective analysis showed.
“Crohn’s fistula is one of the most distressing diseases because it decreases patient’s quality of life and frequently recurs,” South Korean researchers led by Dr. Yong Beom Cho wrote in a study published online March 31, 2015, in Stem Cells Translational Medicine. “It has been reported to occur in 13%-38% of patients with Crohn’s disease and a proctectomy is required in 10%-18% of Crohn’s patients over the course of the disease.” To date, they continued, treatment with antibiotics and biological agents remain unsatisfactory “because they fail to achieve complete closure, lower recurrence, and limit adverse effects.”
Over the past several years, researchers have been evaluating the efficacy of stem cell therapy for treating Crohn’s fistula, including those derived from bone marrow and adipose tissue. An earlier phase II trial conducted by Dr. Cho of the department of surgery at Samsung Medical Center, Seoul, South Korea, and associates found that using mesenchymal stem cells derived from adipose tissue (ASCs) resulted in favorable efficacy and complete healing in 82% of 43 patients at 1 year ( Stem Cells Trans. Med. 2013;31:2575-81 ). The purpose of the current trial was to evaluate the outcome of this approach by following the patients for an additional year.
For the current phase II trial, the researchers followed 41 of the 43 patients from the initial trial, which took place at five hospitals in South Korea from January 2010 to August 2012 and involved one or two injections of ASCs into the tract of fistulae associated with Crohn’s disease (Stem Cells Trans. Med. 2015 March 31 [doi:10.5966/sctm.2014-0199]). At baseline the mean age of patients was 26 years, 68% were male, the mean fistula length was 4.6 cm, and the average duration of Crohn’s disease was 58 months. Modified intention-to-treat (mITT) and modified per protocol (mPP) analysis were used to assess efficacy. Patients who received other surgical procedures or operations involving the injection site were excluded from the mPP analysis, while the mITT analysis included patients who received ASC treatment and had efficacy data at month 24.
At 24 months, complete fistula healing was observed in 81% of patients in the mPP analysis and 75% of patients in the mITT analysis. Furthermore, 83% of patients who showed complete closure at week 8 after ASC injection still showed complete closure at 24 months. No adverse events related to the administration of ASCs were observed.
“ASCs represent a novel therapeutic option for Crohn’s fistulae with a high risk of recurrence, showing durable efficacy with low recurrence, even in cases in which healing cannot be achieved with biologics or in which conventional surgical procedures cannot be performed,” the researchers concluded. “Such refractory patients should be referred to tertiary centers where optimal therapy, including stem cell implants, can be offered.”
The work was supported by the National Institutes of Health Clinical Trials. Two of the study authors are employees of Anterogen Co. The remaining researchers reported having no relevant financial conflicts.
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