In re Efthymiopoulos (Fed. Cir. 2016)
In a split opinion, the Federal Circuit has affirmed the PTAB’s determination of obviousness. Biota’s patent claims influenza treatment through oral inhalation of zanamivir while the prior art teaches the identical treatment by nasal inhalation. A second prior art reference also suggests that similar compound can be taken via “inhalation” (without the nasal or oral modifier). On appeal, the Federal Circuit affirmed that the general inhalation disclosure “is reasonably understood to disclose inhalation by either the nose alone, mouth alone, or both.”
Judge Newman writes in dissent:
The PTAB and now this court rule that it was obvious to administer this drug by oral inhalation, although there is no reference, no prior art, no suggestion, proposing that this mode of application might succeed, or that it should be tried. There was evidence of skepticism even as oral inhalation was evaluated. There was no contrary evidence. The evidence on which the Board and now this court rely is the evidence in the patent application itself, describing oral inhalation, its benefits, and its effectiveness. Upon learning this information from this inventor’s disclosure, the Board found that it was obvious, and my colleagues agree that it is obvious to them.
In its brief, the PTO wrote:
Efthymiopoulos seeks to capture as his exclusive property right a particular (but not particularly new) way of delivering an old compound to treat a well-known disease. Specifically, Efthymiopoulos claims a method for treating influenza, an infectious disease of the respiratory tract caused by influenza (flu) viruses, by administering zanamivir, a compound known in the prior art as an inhibitor of influenza virus production, by inhalation of zanamivir through the mouth alone. Efthymiopoulos contends that his contribution to the art is the route of inhalation – treating influenza solely by oral inhalation.
But the evidence of record shows that oral inhalation would have been obvious. Specifically, as of the effective filing date, skilled artisans understood inhalation to mean oral, nasal, or both. The prior art was replete with available oral inhaler devices for use with well-known micronized dry powder formulations. Skilled artisans also knew that oral inhalation delivers more drug to the lungs and that nasal inhalation delivers more drug to the nasal cavity. Skilled artisans further knew that some strains of influenza infect the lungs, and that young children are more susceptible to lung infections.
The case here is an example of the difficulty with the flexible obviousness analysis — it allows for well supported arguments on both sides.