USA Expands Smallpox Treatment Stockpile

The U.S. Food and Drug Administration (FDA) announced the Approval of Tembexa (brincidofovir) to treat smallpox.

Tembexa, an oral antiviral, was developed in conjunction with the U.S. Biomedical Advanced Research and Development Authority (BARDA). 

The FDA granted Approval of Tembexa to Chimerix Inc.

Although the World Health Organization declared smallpox eradicated in 1980, there have been longstanding concerns that the virus that causes smallpox, the variola virus, could be used as a bioweapon.

Although naturally occurring smallpox no longer exists, concerns about potential uses of variola virus as a bioweapon has made smallpox drug development an essential component of the U.S. medical countermeasures response, says the FDA.

Recently, BARDA exercised the final $12 million option under the $202 million order for the JYNNEOS vaccine. JYNNEOS is the only FDA-Approved non-replicating smallpox and monkeypox vaccine. 

Before its eradication in 1980, the variola virus was mainly spread by direct contact among people. Symptoms typically began 10 to 14 days after infection and included fever, exhaustion, headache, and backache. 

Because smallpox is eradicated, the effectiveness of Tembexa was studied in animals infected with viruses that are closely related to the variola virus. Effectiveness was determined by measuring animals’ survival at the end of the studies. 

Safety information to support Approval of Tembexa was derived from clinical trials of the drug for a non-smallpox indication, primarily from patients who received hematopoietic stem cell transplants. The most common side effects when using Tembexa are diarrhea, nausea, vomiting, and abdominal pain.

Previously, Tembexa received Priority Review, Fast Track, and Orphan Drug Designations by the FDA. 

PrecisionVaccinations publishes research-based news.