Darvadstrocel: A Review in Treatment-Refractory Complex Perianal Fistulas in Crohn's Disease.

Darvadstrocel (Alofisel® ) consists of a suspension of expanded human allogeneic adipose-derived mesenchymal stem cells (eASCs). It is the first mesenchymal stem cell (MSC) advanced therapy approved in the EU for the treatment of complex perianal fistulas in adult patients with non-active/mildly active luminal Crohn's disease, when fistulas have shown an inadequate response to ≥ 1 conventional or biologic therapy. In the pivotal phase 3 ADMIRE-CD trial in this difficult-to-treat patient population, after standard-of-care fistula conditioning, add-on therapy with a single dose of darvadstrocel (120 million eASC) administered into the tissue surrounding complex perianal fistulas was significantly more effective than placebo (saline), with the darvadstrocel group having a higher combined remission rate (i.e. clinically-assessed fistula closure plus MRI-assessed absence of abscesses) at 24 weeks in intent-to-treat (ITT primary analysis), modified ITT and per-protocol analyses. Clinical remission was maintained in > 50% of patients at 52 weeks' follow-up. Given the very limited treatment options available for this difficult-to-treat rare condition, darvadstrocel is a promising, novel, minimally invasive therapy that represents an important advance in the therapeutic options for complex perianal fistulas in adult patients with non-active/mildly active luminal Crohn's disease when fistulas have shown an inadequate response to ≥ 1 conventional or biologic therapy.