Aclaris Therapeutics Shares Fall On Mixed Results From Mid-Stage Eczema Trial

Aclaris Therapeutics Inc ACRS 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 (69.7% versus 58.7% in the pooled vehicle group, p=0.035). 

While not statistically superior, ATI-1777 2% once daily (QD) showed a trend toward significance (68.3% compared to 59.5% in vehicle, p=0.086).

In the per-protocol population, or all patients with week 4 data with no major protocol deviations, ATI-1777 2% BID demonstrated a 70.8% reduction in EASI compared to a 58.5% reduction in vehicle (p=0.025).

ATI-1777 2% QD demonstrated a 68.4% reduction in EASI compared to a 59.7% reduction in vehicle (p=0.102).

In addition, a post-hoc analysis of only patients who had baseline severity of moderate or severe AD showed a 65.6% and 65.1% reduction in the EASI score at week 4 in ATI-1777 2% BID and ATI-1777 2% QD, respectively, compared to a 52.6% reduction in the pooled vehicle group (p=0.029 and 0.040, respectively).

ATI-1777 2% BID and 2% QD also showed improvement in the proportion of patients who reached an IGA-TS response (Investigator Global Assessment Treatment Success) at week 4 (ATI-1777 2% BID: 37.2% compared to 27.1% in the vehicle, p=0.141; ATI-1777 2% QD: 36.6% compared to 26.3% in the vehicle, p=0.137). 

The per-protocol population demonstrated an IGA-TS response at week 4 of 41.8% for ATI-1777 2% BID compared to 25.5% in the vehicle (p=0.059) and 39.8% for ATI-1777 2% QD compared to 25.4% in the vehicle (p=0.079).

A PK analysis showed minimal levels of exposure to ATI-1777. 

No meaningful safety findings were observed, and ATI-1777 was well tolerated. 

Price Action: ACRS shares are down 22.5% at $0.99 on the last check Wednesday.