Establishing long-felt need requires objective evidence that an art-recognized problem existed for a long period of time without solution.1 In the past, courts identified the long-felt but unmet need as an art-recognized problem that was not necessarily defined in terms of the solution set forth in the claimed invention. For example, in AstraZeneca Pharmaceuticals LP v. Anchen Pharmaceuticals Inc.2, the claims of the patent-in-suit were directed to sustained release formulations of the antipsychotic compound quetiapine and a method for treating psychotic states or hyperactivity by administering an effective amount of the claimed formulations. The court defined the long-felt but unmet need more broadly than merely a method for treating psychotic states or hyperactivity by administering an effective amount of the claimed formulation, noting “a recognized but unmet medical need for an effective drug therapy for the treatment of bipolar depression” arose prior to the time of the invention.3 Similarly, in Eli Lilly & Co. v. Zenith Goldline Pharmaceuticals Inc., the patent-in-suit claimed both olanzapine and use of the compound to treat schizophrenia.4 There too, the trial court defined the long-felt but unmet need more broadly than merely using olanzapine to treat schizophrenia, recognizing a “long-felt but unsolved need for a safe atypical antipsychotic from 1975 until 1990.“5

In a departure from this practice, recent district court and Patent Trial and Appeal Board decisions have narrowly defined the relevant problem-to-be-solved in analyzing long-felt need to that claimed by the patent-in-suit. For example in Allergan Inc. v. Teva Pharmaceuticals USA Inc., when considering long-felt need the district court focused, narrowly, on whether there was an option for those other than the inventors “to invent in the area of castor oil/cyclosporine emulsions” to treat dry eyes before the time of the invention.6 The court did so despite initially defining the long-felt but unmet need in far broader terms, explaining that “prior to Restasis, there were no treatments for dry eye and KCS that would restore patients’ natural tearing without significant risk of adverse side effects.“7 Similarly, in Amerigen Pharmaceuticals Limited v. Janssen Oncology Inc., the PTAB limited long-felt need to the claimed invention, reasoning, in part, that “although drugs that contribute to increasing cancer patient survival rates nearly always satisfy a long-felt need, Patent Owner has not presented sufficient evidence that a specific long-felt need existed for the method of administering abiraterone acetate and prednisone claimed in the ’438 patent.“8

In both instances, the judges relied on hindsight to define the problem to be solved coextensively with the patentee’s solution to that problem. But, by allowing hindsight to seep into this analysis, objective evidence is unfairly undervalued or dismissed entirely. This is especially problematic since objective indicia of nonobviousness are meant to “guard as a check against hindsight bias.“9 Worse still, this practice creates a circular tension in which the long-felt need is framed so narrowly that the only possible solution to the problem is the claimed invention.

To avoid these issues, the relevant problem-to-be-solved in analyzing long-felt need should not be narrowly defined by the claims of the patent-in-suit. Instead, long-felt but unmet need should be defined as the art-recognized problem existing for a long period of time without solution. Only then should the court consider whether sufficient evidence has been proffered to establish that those of ordinary skill in the art knew of the long-unsolved problem, that the problem was solved by the claimed invention, and that the problem had not been solved by anyone else before the priority date of the challenged claims.10

Moreover, by properly defining the unsolved problem, blocking patent rights are unlikely to eviscerate compelling evidence of long-felt but unmet need. A so-called blocking patent is a patent that prevents a third party from practicing or commercially exploiting something that utilizes an underlying patented invention. In Allergan, the court not only narrowed its definition of long-felt need, it then relied on so-called blocking patents to minimize the relevance establishing that Allergan met this need.11 Specifically, the Allergan court dismissed any consideration of long-felt but unmet need explaining that Allergan met the need “not because Allergan was at the forefront of innovation in a competitive setting, but because it had enjoyed a long period of patent protection, which ensured it would be the only party that would be able to invent and exploit a cyclosporine/castor oil product.“12 But, had the Allergan court adopted its initial definition of the long-felt but unmet need, namely for a dry eye and KCS treatment that would restore patients’ natural tearing without significant risk of adverse side effects, no blocking patent would likely encompass all solutions to the defined problem. Indeed, applying the district court’s initial definition of long-felt need, one need not practice or infringe a claim of a blocking patent to solve the defined problem, as all avenues of experimentation to solve the problem would be available to a skilled artisan.

To ensure that objective evidence of nonobviousness is not ensnared in the trap of hindsight reasoning, long-felt but unmet need should be analyzed from the perspective of persons of ordinary skill in the art as an art-recognized problem that that is not defined in terms of the solution set forth in the claimed invention.