The positive results come from the 104-week extension period of ADMIRE-CD, a randomized, double-blind, placebo-controlled Phase 3 clinical trial (NCT01541579) looking to confirm the safety and efficacy of a single administration of Cx601 in the treatment of complex perianal fistulas in Crohn’s disease patients.
Cx601 treatment consists of injecting previously allogeneic expanded adipose-derived stem cells, or eASC, (i.e., stem cells derived from adipose tissue of a donor, and not derived from patients themselves) directly into the lesions.
The study’s primary endpoint was closure of all treated external openings draining at baseline within 24 weeks of treatment with lack of collections over 2 cm (confirmed by magnetic resonance imaging).
In total, 212 patients were randomized to receive Cx601 or a placebo. TIGenix reported that Cx601 achieved statistical superiority on the primary endpoint, with 49.5 percent of patients exhibiting combined remission, compared to 34.3 percent in the placebo group, in August 2015.
In terms of safety, adverse effects were comparable between Cx601 and placebo arms.
The new results come from the 37 patients who concluded the long0term extension study period that spanned week 52 to week 104, or two years. Of these patients, 23 were treated with Cx601, while 14 were given a placebo drug.
Results from this long-term extension showed that the clinical remission rate between Cx601 treatment and placebo groups was maintained. The drug tolerability was also maintained, and both serious and non-serious treatment-related adverse events were similar between the two patient groups.
“This is the final set of data from this landmark ADMIRE-CD study. The week 104 data on the patients who stayed in the trial continue to prove the value of Cx601 for this very difficult to treat patient population, and are consistent with the results communicated at week 24 and week 52,” Marie Paule Richard, chief medical officer of TiGenix, said in a press release.
“Not only did this long term extension show the safety and tolerability of Cx601 but it indicates that clinical remission was maintained after a single administration of Cx601, as compared with best available standard of care, two years after administration,” Richard said.
Based on the positive 24-week Phase 3 study results, TiGenix submitted a Marketing Authorization Application to the European Medicines Agency (EMA) in early 2016. TiGenix is preparing to develop Cx601 in the U.S. under a special protocol assessment procedure (SPA) agreement reached with the FDA in 2015.