DURHAM – Chimerix, a Durham-based biopharmaceutical company that’s developing novel antiviral medicines for unmet medical needs, has received Orphan Drug Designation from the U.S. Food and Drug Administration for brincidofovir, its smallpox treatment.

[The company also on Monday reported progress on CMX521, which it says is the first direct-acting antiviral specifically for the treatment and prevention of norovirus.

[“CMX521 showed activity in vitro against all strains of norovirus tested, suggesting broad efficacy against human noroviruses and supporting the ongoing Phase 1 study,” Chimerix said. The data will be presented  at the International Conference on Antiviral Research (ICAR) hosted by the International Society for Antiviral Research this week.]


Brincidofovir, Chimerix’s lead product candidate, is a nucleotide analog that has antiviral activity against all five families of DNA viruses that affect humans, including adenoviruses and variola virus, the virus that causes smallpox. Brincidofovir has a high barrier to resistance, no bone marrow suppression and a low risk of kidney toxicity, the company said in a news release.

Chimerix has been working with the Biomedical Advanced Research and Development Authority (BARDA) since 2011 to develop brincidofovir, which has demonstrated improved survival rates following confirmed orthopoxvirus infections in multiple animal models.

“Though declared eradicated in the late 1970s, smallpox, whether natural or synthetic, continues to be a potential global threat in today’s interconnected world,” said M. Michelle Berrey, M.D., M.P.H., president and chief executive officer of Chimerix. “We are committed to completing the development program for brincidofovir as a much-needed treatment option for smallpox, in close collaboration with BARDA and FDA.”

The Orphan Drug Designation program provides special status to drugs and biologics intended for the safe and effective treatment, diagnosis or prevention of rare diseases and disorders that affect fewer than 200,000 people in the United States. The designation provides manufacturers with incentives including a waiver of the FDA’s prescription drug user fee and tax credits for qualified clinical testing.

Brincidofovir has also received Fast Track designation from the FDA for adenovirus, cytomegalovirus (CMV) and smallpox. That status expedites the review of drugs that treat serious conditions or fill an unmet medical need so patients can get them sooner.

Brincidofovir has also received Orphan Medicinal Product Designation from the European Commission for the treatment of adenovirus, the prevention of CMV disease and the treatment of smallpox.

That status, similar to the FDA’s Orphan Drug Designation, is granted to drugs for the diagnosis, prevention or treatment of life-threatening or very serious conditions that affect no more than 5 in 10,000 people in the European Union. It gives drug companies incentives such as fee waivers for the regulatory procedures and 10-year market exclusivity.

Chimerix is dedicated to discovering, developing and commercializing medicines that improve outcomes for patients with weakened immune systems. Its proprietary lipid conjugate technology and compound library have produced brincidofovir; CMX157, an antiviral for treating hepatitis B that was licensed to ContraVir Pharmaceuticals; and CMX521, the first clinical stage, direct-acting antiviral for the treatment and prevention of norovirus.

Chimerix, founded in 2000, is listed on the NASDAQ Global Market stock exchange.