The first new type of flu drug in more than a decade could seek U.S. regulatory approval as early as next year, aided by U.S. government efforts to combat pandemics and biological threats.
Japan’s Fujifilm Holdings Corp. and partner MediVector Inc. have enrolled more than half the 1,600 patients needed for advanced U.S. studies on the medicine called favipiravir, Kouichi Yamada, senior operations manager of Fujifilm’s pharmaceutical products division said in an interview. They plan to complete the trials around March and file for approvals thereafter.
While favipiravir has yet to win Japanese approval as a seasonal influenza treatment, the drug’s U.S. studies are being funded by the Department of Defense. The agency’s BioDefense Therapeutics unit in an October statement said it was helping develop the new treatment to improve the U.S.’s bio response capability and protect the military from flu pandemics.
Clearance from the Food and Drug Administration would give Fujifilm its first medicine in the U.S. and offer doctors an alternative against viral strains capable of evading treatments such as Roche Holding AG’s Tamiflu. While the Fujifilm drug is currently in human trials for seasonal flu, two studies in animals published earlier this year suggested that it is also a candidate for treating the deadly Ebola virus that is spreading in Africa.
The Department of Defense’s media department didn’t immediately respond to an e-mail seeking comment.
A Phase II study in the U.S. using 10 grams of the drug showed the medicine reduced flu symptoms against a placebo. The chance of U.S. regulatory approval “is relatively high,” and the drug could generate as much as $200 million in annual sales for Fujifilm there, estimates Hirosuke Takayama, an equity analyst at SMBC Nikko Securities Inc.
The Japanese company isn’t running human tests for Ebola because it lacks the resources and expertise, said Takatoshi Ishikawa, general manager for the pharmaceutical products division.
“The U.S. is funding the studies with a hope that the medicine will treat such diseases,” he said. “We are leaving it to the U.S. on how it plans to take advantage of the medicine.”
The treatment targets polymerase, an enzyme viruses use to replicate inside the body. Polymerase inhibitors are exciting because they block the flu virus at a much earlier stage than the existing drugs, said Peter Palese, chair of Mount Sinai School of Medicine’s department of microbiology in New York. By contrast, Tamiflu and GlaxoSmithKline Plc’s Relenza target a protein on the surface of the virus and stops it from spreading.
Researchers in Australia last year reported finding Tamiflu-resistant swine flu in about 2 percent of cases globally. Roche got FDA approval for Tamiflu in 1999, and it is now the world’s best-selling influenza antiviral drug. Roche spokesman Nicolas Dunant declined to comment on any potential impact to Tamiflu from new competition.
Fujifilm, a maker of photofilm, is diversifying into healthcare to offset falling film sales. It got the rights to the flu treatment in 2008 by acquiring a controlling stake in Japanese drugmaker Toyama Chemical Co.
It has struggled to get approval for the antiviral in Japan, a country that prescribes more flu drugs than any other. The last stage of studies in Japan, using a total of 4.8 grams of favipiravir, failed to show it reduced symptoms as well as Tamiflu even though more patients were free from the virus. A previous study in animals showed the medicine has a risk of birth defects when used during pregnancy.
The drug in March received an approval in Japan for stockpiling for pandemics after the mid-stage U.S. study showed the reduction in flu symptoms. Japan’s health ministry has now asked for more data using a higher dosage of 8 grams. Fujifilm is running a trial and discussing details with Japanese regulators, Yamada said.