Cell Therapeutics Inc said the U.S. Food and Drug Administration lifted a hold imposed in June last year on studies testing the company's blood cancer drug.
The company's shares rose about 3 percent to $1.97 in premarket trading on Thursday.
Cell Therapeutics said it received the notification from the regulator on December 26.
The FDA placed the hold after a patient treated with a combination of the drug, tosedostat, and a chemotherapy drug died of a heart muscle infection.
Under the hold, the company could not enroll new patients in any trials of tosedostat.
The regulator asked for more information on all heart-related events in patients treated with the drug.
Tosedostat is being tested in mid-stage trials in the United States and European Union on elderly patients with two forms of blood cancer - acute myeloid leukemia and myelodysplastic syndrome.
(Reporting by Vrinda Manocha in Bangalore; Editing by Kirti Pandey)