The need to sift through tens of thousands of potential variations on the disclosed embodiments to determine their viability, with each taking on the order of weeks in a field that is generally unpredictable, constitutes excessive and therefore undue experimentation, even if it is all fairly routine. In order to capture such broad claim scope, it appears that the applicant will have to provide at a minimum at least several example compounds and guidance as to how others could be produced while retaining similar properties.
Background / Facts: The patents-in-suit relate to the use of rapamycin for the treatment and prevention of restenosis, which is the renarrowing of an artery (e.g., following angioplasty surgery). While the claims use the term “rapamycin,” the parties agree that the shared specification discloses only one rapamycin species called sirolimus. Yet, there are tens of thousands of other potential compounds that fall under this class and would require screening to identify whether they have similar immunosuppressive and antirestenotic properties.
Issue(s): Whether practicing the full scope of the claims requires excessive, and thus undue, experimentation.
Holding(s): Yes. Practicing the full scope of the claims would require synthesizing and screening each of at least tens of thousands of compounds. “Even a considerable amount of experimentation is permissible, as long as it is merely routine or the specification provides a reasonable amount of guidance regarding the direction of experimentation. … Yet, routine experimentation is not without bounds.” Here, the specification “discloses only a starting point for further iterative research in an unpredictable and poorly understood field.” Merely synthesizing the different candidate compounds could require a complicated and lengthy series of experiments in synthetic organic chemistry, and even then, one of ordinary skill would need to assay each of at least tens of thousands of candidates. The patentee’s expert conceded that it would take technicians weeks to complete each of these assays. “The specification offers no guidance or predictions about particular substitutions that might preserve the immunosuppressive and antirestenotic effects observed in sirolimus. The resulting need to engage in a systematic screening process for each of the many rapamycin candidate compounds is excessive experimentation.”