A new drug to help address the growing problem of antiviral drug resistance and add to the tools available to fight pandemic and seasonal influenza will be developed under a contract awarded today by the U.S. Department of Health and Human Services. The $44 million, 33-month contract with Romark Laboratories of Tampa, Fla., supports advanced development of Nitazoxanide to treat influenza in adults and teens.

Influenza viruses have become resistant to two of the four drugs approved to treat the flu, and resistance has begun to emerge to the remaining two drugs. Nitazoxanide is approved in the United States to treat two waterborne parasites, Giardia lamblia and Cryptosporidium parvum, in adults and children. Previous studies with Nitazoxanide have shown promising results in treating strains of influenza that are resistant to currently approved antiviral medications.

The drug has a unique mechanism of action that targets a process in the body’s cells needed by the virus rather than targeting the virus itself as other antiviral drugs do. Targeting these cells rather than the influenza virus reduces the risk that the virus will develop resistance against this drug. In laboratory experiments, Nitazoxanide has also shown potential against other non-influenza respiratory viruses that cause disease in people and thus may have broad spectrum applicability.

“Repurposing an existing drug with a proven safety record that can work in combination with other approved treatments is a key strategic goal and would greatly enhance our nation’s domestic response capabilities for pandemic and seasonal influenza,” said Robin Robinson, PhD, director of HHS’ Biomedical Advanced Research and Development Authority (BARDA).

Under the contract, Romark will conduct the final studies needed for FDA approval of the drug for influenza treatment. The studies include a Phase 3 clinical trial to evaluate Nitazoxanide alone and in combination with an approved influenza antiviral drug to treat uncomplicated influenza infection in people ages 13 to 65.


Nitazoxanide is the fourth antiviral drug candidate under development in BARDA’s pandemic influenza program and the second in development that focuses on a host target as a mechanism of action rather than a conventional approach toward a viral target

BARDA’s pandemic influenza program also supported advanced development of Flucelvax, the first cell-based influenza vaccine in the United States to earn FDA approval, and FluBlok, the first FDA-approved influenza vaccine to use recombinant DNA technology.