Durham-based Chimerix, Inc. (NASDAQ:CMRX) announced a 15-month extension Monday to allow the company to continue work on a treatment for smallpox. The contract, with the Biomedical Advanced Research and Development Authority (BARDA), is worth $13 million.

Chimerix has been working with BARDA for about four years on research and development of an oral antiviral medicine called brincidofovir to treat smallpox. The company has begun testing the drug on humans with an eye toward FDA approval.

M. Michelle Berrey, Chimerix president and CEO, said, “Our partnership with BARDA has resulted in significant progress for brincidofovir as a medical countermeasure for smallpox in the event of a bioterror attack or accidental release. This award will continue to support our brincidofovir smallpox development program for which we recently reported positive topline results showing a statistically significant survival benefit. This is an important step toward a potential FDA approval as the first antiviral treatment for smallpox.”