Stem Cell Therapy for Complex Perianal Fistulas: Why the ADMIRE CD II Trial Missed Its Mark

The ADMIRE CD II Phase 3 trial did not meet its primary endpoint, showing no statistically significant difference in combined remission rates between darvadstrocel and placebo at 24 weeks.
Remission was achieved in 48.8% of the darvadstrocel group compared to 46.3% in the placebo group, which received standard-of-care surgical closure.
The high placebo response rate (46.3%) in this trial significantly exceeded rates seen in previous studies, potentially masking the therapeutic effect of the stem cell dispersion.
Safety profiles remained consistent with previous findings, with no new safety signals or increased risk of treatment-emergent adverse events identified.