DURHAM – BioCryst Pharmaceuticals Inc. has been given an additional $3.5 million by the federal government to support clinical trials using one of the company’s signature drugs in the treatment of yellow fever.

The Durham-based biotechnology company, which makes drugs that block key enzymes in the development of diseases, holds a contract with the National Institute of Allergy and Infectious Diseases that is now worth $43 million in total.

According to the company’s press release, the NIAID has funded BioCryst since September 2013 in developing treatments for Ebola virus disease and Marburg virus disease using galidesivir, an antiviral drug that BioCryst holds the global rights to.

The company said galidesivir has also shown survival benefits against yellow fever in animal studies.

Yellow fever is a serious viral disease transmitted by infectious mosquitos. According to the World Health Organization, the disease is endemic in tropical areas of Africa and Central and South America.

While an effective vaccine exists to prevent the development of the disease in patients, no approved treatment exists for those who already have yellow fever.

“We appreciate the NIAID’s expanded support for galidesivir, which allows us to evaluate our broad-spectrum antiviral in clinical trials in patients suffering from yellow fever,” BioCryst CEO Jon Stonehouse said in the release. “This program could prove to be very valuable in the overall evaluation of galidesivir for inclusion in the Strategic National Stockpile.”

The Strategic National Stockpile, compiled by the U.S. government’s Centers for Disease Control and Prevention, is the nation’s largest supply of potentially life-saving pharmaceuticals and medical supplies for use in a public health emergency.

According to the World Health Organization, yellow fever is responsible for up to 170,000 severe cases and up to 60,000 deaths globally each year. In recent years, yellow fever outbreaks have intensified in certain parts of the world due to vaccine shortages.

In Brazil, large rural areas surrounding cities like Sao Paulo and Rio de Janiero have been hit by yellow fever outbreaks in recent years. These areas have not traditionally been threatened by yellow fever, meaning vaccinations have not been highly emphasized to their residents.

As a result, no more than a few dozen cases of yellow fever per-year had come to be expected in Brazil. But since December 2016, Brazil’s Ministry of Health has recorded 2,043 cases and 676 deaths due to the disease.

“We can call this the biggest outbreak in modern times,” Dr. Mauricio Lacerda Nogueira, president of the Brazil Society for Virology, told NPR last April. “Since the middle of the 20th century we never had an outbreak of this size.”

BioCryst was trading at $6.96 Monday morning, a 1 percent decline from the day’s opening.

This story is from the North Carolina Business News Wire, a service of UNC-Chapel Hill’s School of Media and Journalism