In Re: Efthymiopoulos (Before Prost, C.J., Newman, and Bryson, J.) (Opinion for the court, Prost, C.J.) (Dissenting opinion, Newman, J.)
A divided panel of the Federal Circuit affirmed the Board’s rejection of all pending claims as obvious in an appeal arising from a method for treating or preventing influenza by oral inhalation of zanamivir.
One reference disclosed that zanamivir can be inhaled intranasally to treat and prevent influenza, and a second reference disclosed that a compound similar to zanamivir can be administered by “inhalation” to treat and prevent influenza.
Zanamivir and the similar compound are “adjacent homologues,” meaning “they are part of a series of compounds that differ in structure only by a single substituent.” The Court agreed with the Board’s finding that substitution of zanamivir for this similar compound for oral inhalation would have been obvious.
The second reference “expressly discloses administration through ‘oral,’ ‘nasal,’ or other forms ‘suitable for administration by inhalation.’” The Court further agreed with the Board that: “[I]nhalation can only be carried out via the nose or the mouth. Since [the second reference] does not limit its disclosure to nasal inhalation, it is reasonably understood to disclose inhalation by either the nose alone, the mouth alone, or both.”
The appellant argued that a person of ordinary skill would not expect oral zanamivir to be effective and would instead expect only nasal inhalation to work. The Court rejected this argument, noting that it was known in the art that “although the influenza virus primarily attacks the upper respiratory tract, certain strains of the virus also attack the lower respiratory tract” and “oral inhalation delivers more drugs to the lungs as compared to nasal inhalation.”
The Court also upheld the Board’s finding that the appellant’s proof of unexpected results was unpersuasive, and substantial evidence supported the Board.
In her dissent, Judge Newman stated that “there is no reference, no prior art, no suggestion, proposing that this mode of application might succeed, or that it should be tried.” She found that to reach their conclusion, “[t]he evidence on which the Board and now [the Federal Circuit] rely is the evidence in the patent application itself, describing oral inhalation, its benefits, and its effectiveness.” In her opinion, the Board and her colleagues, “deem this treatment of influenza obvious on the ground that inhalation occurs only through the nose or the mouth. Thus the court rules that the discovery of effective treatment by oral inhalation is obvious to the court, although not obvious to experts, and not suggested in the prior art.”
References can be combined to show that it would have been obvious to zero in on one of a few options disclosed in the prior art.