Aclaris Shares Tank as Skin Disorder Drug Fails Mid-Stage Study

Reuters staff

March 07, 2023

(Reuters) - Aclaris Therapeutics Inc said on Monday its experimental drug failed to meet the main goal of a mid-stage study to treat a painful skin disorder, sending its shares tumbling more than 36% in premarket trading.

The drug, zunsemetinib, did not meet the main goal of reducing abscesses in patients with moderate to severe hidradenitis suppurativa (HS) at week 12, compared with a placebo. 

HS is a chronic inflammatory skin condition that causes abscesses and scarring on the skin.

The study also failed to meet its secondary goals, which included percentage of patients who achieved at least a 50% reduction in number of inflammatory lesions, Aclaris said. 

The drug is being tested to treat other inflammatory conditions such as rheumatoid arthritis and psoriatic arthritis, far bigger markets than HS. Jefferies has estimated that around 0.1% of the U.S. population has hidradenitis suppurativa.

The levels of enzyme creatine phosphokinase appeared to be higher in more patients compared to commonly used rival drugs to treat inflammatory conditions, Stifel analyst Alex Thompson said in a note, adding it may cause investor debate over safety of the drug.

The company's shares trading at $8.17 before the bell.

(Reporting by Raghav Mahobe in Bengaluru; Editing by Anil D'Silva)