Overview of the Trial Results
Aclaris Therapeutics Inc released topline results from its Phase 2b study of ATI-1777, an investigational topical “soft” JAK 1/3 inhibitor, in patients with mild to severe atopic dermatitis (eczema). The trial met the primary efficacy endpoint, the percent change from baseline in the Eczema Area and Severity Index (EASI) score at week 4, with statistical significance for patients treated with ATI-1777 2% twice-daily (BID) compared to patients treated with vehicle. While not statistically superior, ATI-1777 2% once daily (QD) showed a trend toward significance. In the per-protocol population, or all patients with week 4 data with no major protocol deviations, ATI-1777 2% BID demonstrated a remarkable reduction in EASI compared to a reduction in the vehicle. ATI-1777 2% QD demonstrated a reduction in EASI compared to a reduction in vehicle. In addition, a post-hoc analysis of only patients who had baseline severity of moderate or severe AD showed a reduction in the EASI score at week 4 in ATI-1777 2% BID and ATI-1777 2% QD compared to a reduction in the pooled vehicle group.
Market Response
ACRS shares are down 22.5% at $0.99 on the last check Wednesday.
Assessment of Safety and Tolerability
A PK analysis showed minimal levels of exposure to ATI-1777. No meaningful safety findings were observed, and ATI-1777 was well tolerated.
Conclusion
The results of Aclaris Therapeutics’ Phase 2b study of ATI-1777 have led to a 22.5% drop in its shares. While the trial met the primary efficacy endpoint, the market response has been a clear indication of investors’ dissatisfaction with the mixed results.