Complex anal fistulas, abnormal connections between the anal canal and the skin, is a chronic and highly debilitating condition affecting primarily young people and seriously compromising their quality of life.
Management of complex fistulas is a challenge due to the limitations of current treatments, such as surgery and biological therapies, which are not satisfactory.
Medical treatment (combination of antibiotics, antiseptics and anti-inflammatory drugs) only provides temporary relief and is usually not successful in clearing up the condition. Moreover, as a result of limited or aggressive surgical treatment, a dilemma stands between permanent recurrence and fecal incontinence. On the other hand, long-term efficacy of biological treatment is limited and adverse events can occur. The use of expanded adipose-derived mesenchymal stem cells (Cx401) is a novel cell therapy based on immunoregulation and cell proliferation, which helps repair damaged tissue.
In a multicenter, randomized, controlled trial, researchers from three Mayor Hospitals in Madrid, Spain and led by La Paz University Hospital, evaluated the efficacy and safety of Cx401 in 49 adult patients with complex perianal fistula from cryptoglandular diseases (conditions pertaining to the anal gland, n=35) or Crohn’s disease (an inflammatory disease of the GI tract, n=14). Patients received fibrin glue (biological product that can stimulate wound healing) alone or in addition to Cx401 (20 million stem cells) intralesionally. If not healed, a second dose of fibrin glue or 40 million cells plus fibrin glue was administered. Fistula healing was evaluated at eight weeks. Healing was defined as absence of drainage (spontaneous or by gentle compression) and complete re-epithelization of the external openings. Recurrence rates and quality of life parameters were also analyzed.
This study found that the proportion of patients whose fistulas were healed was significantly higher with Cx401 (71%) than with fibrin glue (16%). Cx401 efficacy was observed in the cryptoglandular and the Crohn?s subpopulations. Very remarkably, at the one-year follow-up, the recurrence rate in the Cx401 group was only 17.6 percent and the impact of Cx401 administration on the patient’s quality of life was significant. At eight weeks after treatment, not a single adverse event related to the stem cells (Cx401) was observed.
“The safety profile of the product turned out to be very promising. We propose this strategy as a novel approach for the healing of patients with perianal fistula, a chronic and highly debilitating disease with unmet needs,” said Damian Garcia-Olmo, M.D., of La Paz University Hospital and lead author of this study. “Overall, we were able to determine that a dose of 20 to 60 million adipose-derived stem cells in combination with fibrin glue is an effective and safe treatment for complex perianal fistula.”