What happened

Shares of Aclaris Therapeutics (ACRS -1.61%) surged on Tuesday, following the release of promising data regarding its experimental treatment for rheumatoid arthritis. 

As of 12:20 a.m. EST today, the pharmaceutical company's stock price was up 212%.

So what 

Aclaris Therapeutics announced preliminary results from a phase 2a clinical trial of ATI-450, an investigational oral MK2 inhibitor, in patients with moderate to severe rheumatoid arthritis. ATI-450 reportedly demonstrated a "marked and sustained reduction" in disease-activity scores in the placebo-controlled study. It was also shown to be generally well tolerated, with no serious adverse events reported during the trial.

A person is pointing to an upwardly sloping line.

Aclaris Therapeutics stock soared on Tuesday. Image source: Getty Images.

Dr. David Gordon, Aclaris chief medical officer, said in a press release, "We believe these data support our hypothesis that MK2 inhibition is an important novel target for the treatment of immuno-inflammatory diseases, such as rheumatoid arthritis, and we look forward to progressing ATI-450 to phase 2b." 

Now what

Aclaris intends to submit a comprehensive analysis of its phase 2a study for peer review in a scientific journal in the coming weeks. Doctors are hopeful that ATI-450 could represent a new way to combat inflammatory diseases.

"Despite recent advances, rheumatoid arthritis continues to be a significant burden for large numbers of patients," said Dr. Stanley Cohen, co-director of the Division of Rheumatology at Presbyterian Hospital in Dallas. "These results are very encouraging and support further development of ATI-450 to treat rheumatoid arthritis with a new mechanism of action."