Shares of Astex Pharmaceuticals Inc. jumped in premarket trading Wednesday after the drug developer announced early results from a mid-stage study of a possible leukemia treatment.

The Dublin, Calif., company said its potential treatment, labeled SGI-110, achieved an overall complete remission rate of 25 percent when studied in a group of patients with a form of acute myeloid leukemia, a rapidly growing bone marrow cancer.

Astex plans to present more details from its research at an American Society of Hematology meeting in December.

The drug developer, which focuses on cancer treatments, is studying SGI-110 in patients with acute myeloid leukemia and myelodysplastic syndromes. Those are conditions in which blood-forming cells in the bone marrow are damaged.

This can progress to acute myeloid leukemia in many patients, according to the American Cancer Society.

The company’s shares climbed 15.5 percent, or 85 cents, to $6.33 in premarket trading about an hour before the market opening. The stock price has ranged between $2.14 and $6.95 over the past year.