Durect Corp.'s DUR-928 failed to show that it was better than a placebo in treating patients with mild to moderate plaque psoriasis in a mid-stage study.

The Cupertino, Calif.-based biopharmaceutical company's stock was down 30.79% to $2.63 as of 11:07 a.m. ET on Jan. 2 on Nasdaq.

Under the phase 2a trial, DUR-928 was evaluated in 22 patients with mild to moderate plaque psoriasis, a condition wherein the skin gets red, itchy, scaly and patchy.

For 28 days, DUR-928 was applied topically once daily on one arm of the patients while a placebo was applied on the arm, targeting similar patches.

Durect in a Jan. 2 press release said DUR-928 failed to meet the primary endpoint of improving skin clarity as well as the secondary goals. DUR-928 was safe and well-tolerated in the trial.

On the basis of the study results, Durect will stop the clinical development of DUR-928 to treat plaque psoriasis, President and CEO James Brown stated. "With the recently announced positive results from our Phase 2a alcoholic hepatitis trial, our focus moving forward with DUR-928, will be on completing the NASH trial in the first half of this year and initiating the Phase 2b AH trial in the middle of the year."

Previously, DUR-928 helped reduce the severity of symptoms in patients with alcoholic hepatitis, a liver disease, in a mid-stage study.