Chimerix’s Potential Smallpox Therapy Gains FDA Priority Review

Chimerix, a Durham-based biopharmaceutical company that’s developing medicines to treat cancer and other diseases, has received good regulatory news for its potential antiviral treatment for smallpox.

The U.S. Food and Drug Administration has accepted the company’s filing of a New Drug Application (NDA) for the investigational therapy Brincidofovir (BCV), the company announced in a news release. The FDA also gave the therapy Priority Review and set an action date of April 7, 2021, under the Prescription Drug User Fee Act.

Chimerix has developed BCV with ongoing assistance and funding from the Biomedical Advanced Research and Development Authority (BARDA), part of the office of the Assistant Secretary for Preparedness and Response within the U.S. Department of Health and Human Services.

“Our team has continued to execute extremely well in collaboration with BARDA to advance this program,” said Mike Sherman, chief executive officer of Chimerix. “As we’ve observed in recent months, the threat of serious viral infections requires robust pandemic plans to protect the population and our economy. With BCV, we hope to provide that protection from smallpox, and look forward to working with BARDA on next steps in making this countermeasure available to patients in advance of an outbreak.”

The FDA's acceptance of the NDA indicates the application is sufficiently complete to permit a substantive review. A Priority Review designation accelerates the agency’s review time from 10 months to a goal of six months and is granted to drugs that may offer a significant improvement in the safety or effectiveness of the treatment, prevention or diagnosis of a serious condition.

Chimerix said at this time, the FDA is not planning to hold an advisory committee meeting to discuss the NDA.

BCV is a nucleotide analog lipid-conjugate that has demonstrated antiviral activity against smallpox under the FDA’s Animal Efficacy Rule. That allows testing of investigational drugs in animal models for diseases that are not ethical or feasible to study in humans.

Although smallpox was certified as eradicated in 1980 by the World Health Organization, it continues to be a potential global threat in today’s interconnected world. Smallpox outbreaks killed several hundred million people throughout several centuries.

In addition to BCV, Chimerix is developing another clinical-stage compound, dociparstat sodium (DSTAT), a derivative of porcine heparin with known anti-inflammatory properties.

Compared to commercially available forms of heparin, a blood thinner, DSTAT may be dosed at higher levels without associated bleeding-related complications.

DSTAT is being studied in a Phase 2/3 trial to assess safety and efficacy in adults with acute lung injury with underlying COVID-19. A Phase 3 trial protocol to study DSTAT in acute myeloid leukemia has been developed in alignment with the FDA, and the first patient visit is expected in early 2021.

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