(Reuters) - The U.S. Food and Drug Administration has allowed Alnylam Pharmaceuticals Inc to restart clinical trials on a drug to treat patients with a rare bleeding disorder, the company said on Friday.

All ongoing studies of the drug, fitusiran, had been placed on clinical hold after Alnylam suspended dosing following a patient death in one of the trials testing the drug in hemophilia patients.

Shares of the company were up 3.6 percent at $128.10 in premarket trading.

Alnylam said the FDA approved amended protocols related to the trials, and it expected to resume dosing patients around the end of the year.

The company said the FDA decision pertained to a mid-stage study and late-stage program for fitusiran.

The company and the regulator had reached agreement in November related to risk mitigation measures, including patient education regarding doses of replacement, which is a standard treatment of hemophilia, in the studies of the drug.

Hemophilia is a rare bleeding disorder in which blood does not clot properly.

The drug is being developed to treat hemophilia A and B patients. There are about 400,000 people living with hemophilia A and hemophilia B worldwide