First of its kind, stem cell therapy treatment approved for treating fistulas associated with Crohn’s disease

Crohn’s disease (CD) is an inflammatory bowel disease caused by inflammation in the digestive tract. People with CD experience abdominal pain, diarrhea, fatigue, weight loss and malnutrition. It is a painful and debilitating condition that can sometimes have life-threatening complications.

Approximately 1 out of 3 people with Crohn’s disease develop perianal fistulas, when a small tunnel forms from the end of the bowel to an area of skin around it. About 70% to 80% of these are classified as complex perianal fistulas, where the fistulas are associated with extreme pain, bleeding, inflammation, significantly diminishing the quality of life of patients. Even though many advances have been made in medical and surgical treatment options, perianal fistulas remain challenging to treat.

Solving a complex problem

Due to their regenerative capabilities, researchers have been looking at using stem cells to ‘reset’ the immune systems of those with CD. The idea is that stem cells will generate new cells that may reduce inflammation, stimulate repair, and dampen the immune response that leads to CD. With perianal fistulas, the hope is that stem cells may mediate their closure, particularly in patients who do not respond to current treatment options.

Tested in clinical trials

Takeda pharmaceutical’s Alofisel is an example of a stem cell product that has gone through clinical trials to prove its effectiveness.

In one interventional clinical trial (NCT01541579), 212 patients with complex perianal fistulas were given a single injection of these stem cells in addition to standard of care. Follow up studies show that 24-weeks after treatment more than 51% of patients who received the Alofisel injection achieved combined remission compared to just 35% in the control group. This difference was maintained over 52 weeks (56.3% vs 38.6%).

Approval for use

Takeda has already received a Regenerative Medicine Advanced Therapy (RMAT) designation from the food and drug agency (FDA for Alofisel in 2019 based on the success of their clinical trials. It is already in use in Israel, Switzerland and the UK for treating complex perianal fistulas in patients that do not respond to conventional therapies.

The approval to manufacture and market Alofisel in Japan, the first even of its kind to be approved in Japan, may be the beginning of a new era for those patients with difficult to treat CD.


Kotze PG, Spinelli A, Warusavitarne J, Di Candido F, Sahnan K, Adegbola SO, Danese S. Darvadstrocel for the treatment of patients with perianal fistulas in Crohn’s disease. Drugs Today (Barc). 2019 Feb;55(2):95-105. doi: 10.1358/dot.2019.55.2.2914336. PMID: 30816884.

Takeda Pharmaceutical Company Limited. Press release. Sep 2021. Link: