Chimerix, Inc., a biopharmaceutical company developing novel, oral antivirals in areas of high unmet medical need, announced an extension of its contract with the Biomedical Advanced Research and Development Authority (BARDA) for the development of the broad spectrum antiviral, brincidofovir, as a medical countermeasure to treat smallpox.

This latest contract extension provides an additional $13.0 million to Chimerix for a period of 15 months. The company received an initial award from BARDA in February 2011 to support early research and development of brincidofovir in animal models of smallpox and received a contract extension of $17.0 million in September 2014.

M. Michelle Berrey, MD, MPH, president and CEO of Chimerix, 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 programme 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."

Smallpox is estimated to have killed more than one billion people worldwide prior to its eradication declared by the World Health Organisation in 1980 following a global vaccination campaign. Smallpox stocks remain for research purposes in the United States and Russia; however, undeclared stocks are suspected to exist. Routine smallpox vaccination programs were discontinued after the global eradication, and with no antiviral agent approved for the treatment of smallpox, the US population may be susceptible to a bioterror attack with devastating consequences.

Chimerix's lead product candidate, brincidofovir, is an oral nucleotide analog that has shown in vitro antiviral activity against all five families of DNA viruses that affect humans, including the herpesviruses and adenovirus. Brincidofovir has not been associated with kidney or bone marrow toxicity in over 1,000 patients treated to date. Based on the clinically and statistically significant phase 2 results in CMV prevention, Chimerix initiated the 450 patient phase 3 SUPPRESS trial, which completed enrollment in June 2015. If positive, data from SUPPRESS will support Chimerix's initial regulatory submission for brincidofovir for the prevention of CMV infection in adult HCT recipients. Chimerix has also completed enrollment in AdVise, the open-label trial of brincidofovir for the treatment of disseminated or localised adenovirus infection in patients at increased risk of rapid progression to disseminated disease. AdVise completed enrollment in August 2015. Chimerix intends to initiate enrollment in two phase 3 trials in recipients of kidney transplants, a population that continues to have unmet medical need in prevention of CMV and BKV, among other dsDNA viral infections. Chimerix is working with BARDA to develop brincidofovir as a medical countermeasure against smallpox. Brincidofovir has received Fast Track designation from the FDA for CMV, adenovirus, and smallpox.