Dallas Ebola Patient Thomas Duncan Receiving An Experimental Drug

Director of Centers for Disease Control and Prevention Tom Frieden addresses the media on the Ebola case in the U.S. at the Tom Harkin Global Communications Center on Oct. 5, 2014 in Atlanta.

Kevin C. Cox—Getty Images

By Alexandra Sifferlin

October 6, 2014 2:10 PM EDT

Dallas Ebola patient Thomas Duncan is now receiving an experimental drug called brincidofovir, a broad-spectrum antiviral that has appeared promising against Ebola in test tube studies. The drug is currently being tested on animals but has not been tested on humans.

Duncan is still in critical condition, according to Texas Health Presbyterian Hospital.

The drug is an oral medication developed by the biopharmaceutical company Chimerix Inc. The company says the drug received Emergency Investigational New Drug Applications (EIND) from the Food and Drug Administration on Monday morning and it is working with the agency to open a clinical trial. The request for use of investigational drugs can be made by physicians. So far, this drug has only shown effectiveness against the virus in vitro.

Centers for Disease Control and Prevention director Dr. Tom Frieden previously said the decision of whether to treat Duncan with any experimental drugs would be left up Duncan, his family and his doctors.