Adipose tissue-derived stromal stem cells for use in treating refractory complex perianal fistulas in Crohn's disease

A method of treating a complex perianal fistula in a subject having Crohn's disease comprising administering a therapeutic amount of a population of expanded allogeneic adipose tissue-derived stem cells to the subject, wherein:

• (i) the fistula comprises a complex fistula with 1 or 2 internal openings and/or 2 or 3 external openings;
• (ii) the therapeutic amount is a fixed dose of expanded allogeneic adipose tissue-derive stem cells which is administered to the subject in a single administration, wherein a further administration is excluded, wherein each fistula tract receives at least a proportion of this dose and wherein approximately half of the dose is injected into the tissue surrounding the internal opening or openings and the other half is injected into the fistula walls along the fistula tracts;
• and
• (iii) the fixed dose is about 120 million expanded allogeneic adipose tissue-derived stem cells.