(Reuters) -Aclaris Therapeutics on Monday said it would stop development of its rheumatoid arthritis treatment after it failed in a mid-stage trial, sending its shares plunging 84% before the bell.
The trial tested two doses of the drug, zunsemetinib, along with anti-rheumatic drug methotrexate compared to placebo and methotrexate in patients with moderate to severe rheumatoid arthritis who have inadequate response to methotrexate alone.
The patients were given doses of either 20 milligram or 50 milligram of the oral drug, which failed to show improvement in the response rate criteria which assesses reduction in tender and swollen joint count as well as pain.
There was no notable differentiation between zunsemetinib and placebo across any measures of efficacy at 12 weeks, the company said.
The company will also be halting enrollment in an ongoing mid-stage trial studying the drug in psoriatic arthritis.
The drug developer said it is also studying its drug ATI-1777 in patients with moderate to severe atopic dermatitis which is currently in mid-stage trial.
(Reporting by Sriparna Roy in Bengaluru; Editing by Maju Samuel)