Durham-based BioCryst Pharmaceuticals is receiving $12 million from the federal government to fund further development of a possible drug to treat the deadly Ebola virus. Two vaccines are currently being tested in Africa, but no effective treatment exists.

The U.S. Department of Health and Human Services (HHS) announced the contract early Tuesday. The contract was awarded by its Office of the Assistant Secretary for Preparedness and Response.

The government and BioCryst (Nasdaq: BCRX) already have been working together on the project with BioCryst already under contract to receive $23 million. The contract extension announced today is through August 2017.

“BCX4430 currently represents the only single drug that has demonstrated a survival benefit in non-human primates infected with Marburg or Ebola viruses,” said Jon Stonehouse, chief executive officer of BioCryst. “This new BARDA [Biomedical Advanced Research and Development Authority] contract provides continuity in the ongoing development of our broad spectrum antiviral, 4430, and moves this program closer to the finish line.”

HHS described BioCryst’s development as a “promising experimental drug.” Funds will be used for more development and preparations for possible large-scale manufacturing.

The BioCryst compound is known as BCX4430, and it has shown promise in early testing. In Phase 1 trials it is being tested on healthy volunteers.

A compound from GlaxoSmithKline (NYSE: GSK) and one other are currently undergoing early-stage testing in Africa, where the Ebola outbreak has killed more than 10,000 people.

“In non-human primate studies, the drug was effective against Ebola virus and Marburg virus, another virus in the filovirus family, indicating that BCX4430 may be useful as a broad spectrum antiviral drug,” HHS said of the BioCryst drug.

Another Durham firm, Chimerix, recently paused development of its own possible Ebola treatment after the epidemic began to recede.