BioCryst (NASDAQ:BCRX) is taking its intravenous antiviral, peramivir, through Phase III trials in the U.S. for use against seasonal flu. Their Japanese partner, Shionogi, received approval in January, 2010 to use peramivir (Japanese trade name Rapiacta) on adults, both in-hospital and on an out-patient basis.
In February they applied for approval for pediatric use. In early September, Shionogi was notified that Rapiacta has been recommended for approval for pediatric use by the Japanese procedural equivalent of an FDA Advisory Committee. The Japanese FDA normally makes a final determination on these recommendations in four to eight weeks, so I expect final approval in October.
This is an important step in the commercialization of Rapiacta in Japan, because it removes the last hurdle to a Japanese stockpile order for Rapiacta for the coming flu season. BioCryst would receive a royalty on a stockpile order.
The flu this season in the Southern Hemisphere has been a combination of last year’s H1N1, which preferentially infects children and young people, and a variant of the familiar H3N2, which is about three times as deadly as H1N1. Because peramivir/Rapiacta works well against both strains of flu, with very high cure rates in the 90% range, even for ICU patients near death, Japanese doctors will be able to administer Rapiacta without having to type the flu first.
Also, Japan has recognized that most of the circulating H2N2 virus is Tamiflu-resistant, and they need the much higher load of drug in the system that intravenous administration offers, compared to five days of pills. In recent publications, doctors have noted that peramivir is effective even against Tamiflu-resistant virus, that Tamiflu and peramivir together make an effective combination therapy, and that there is a medical case to make peramivir first-line therapy in the ICU, instead of trying Tamiflu or Relenza first.
In contrast to the Japanese FDA’s rapid approval of Rapiacta to protect Japanese citizens, especially children, from the return of H1N1 and an outbreak of the deadlier H3N2, the U.S. FDA has suspended the Emergency Use Authorization they granted during the last flu season for peramivir.
ICU doctors in the U.S. will not have an intravenous treatment for the most seriously ill U.S. adults and children unless this decision is reversed.
Disclosure: Long BCRX