Does Prior Art Lose Significance with Time?

In Leo Pharmaceutical Products, Ltd. v. Rea (Fed. Cir. Aug. 12, 2013), the Federal Circuit by Judge Rader, with Judges O’Malley and Reyna, found Patent No. 6,753,013 non-obvious, reversing a decision by the Board of Patent Appeals and Interferences.  Significantly, the opinion implies that prior art loses its significance for obviousness determinations with time.

The ʼ013 patent teaches that simultaneous treatment with vitamin D and corticosteroids can heal skin conditions more effectively than either alone.  The combination was known in the prior art, but it was not storage stable, as each active ingredient required a different pH environment.  Leo discovered that the solvent polyoxypropylene 15 stearyl ether (POP-15-SE) solved the storage stability problem by permitting vitamin D and corticosteroids to coexist in a single pharmaceutical product.

The Board found the patent obvious based on three pieces of prior art.  Turi, filed in 1977, disclosed a steroid in POP-15-SE, but did not teach vitamin D.  Dikstein, filed in 1984, and Serup, filed in 1993, each disclosed inventions containing vitamin D and a corticosteroid, but neither addressed storage stability, or disclosed the use of POP-15-SE.

The Federal Circuit reversed, holding that the ʼ013 patent was not merely a simple combination of elements; rather, Leo identified and solved the storage stability problem.  Neither Dikstein nor Serup recognized the issue, so there was no reason for one skilled in the art to try to improve upon them using POP-15-SE from Turi.  Only after recognizing the problem would one turn to developing a new formulation.  If such advancement were easy, the court reasoned, it would have been done within months of Dikstein or Serup, not after more than a decade.  The court stated:  “By brushing aside the storage stability issue, the Board erred by collapsing the obviousness analysis into a hindsight-guided combination of elements.”

Even if the only issue were the obviousness of a combination, the Court concluded that the combination in the ʼ013 patent would not have been obvious to try.  It recalled Abbot Laboratories v. Sandoz, Inc. (Fed. Cir. 2008), which stated “KSR did not create a presumption that all experimentation in fields where there is already a background of useful knowledge is ‘obvious to try,’ without considering the nature of the science or technology.”  Judge Rader then noted that the “background of useful knowledge” in this case was published decades before the ʼ013 patent:  “In light of the lack of expectation of a successful result, the failure of the prior art to provide direction, and the substantial number of intervening years between the publication of the prior art and the ʼ013 patent’s filing date, this invention is not simply a case of picking and choosing from a list in order to achieve a compatible and non-deleterious preparation as the Board suggests.”

So it seems that a significant lapse in time between the patent at issue and what should be a relevant piece of prior art for obviousness determinations dulls the significance of that prior art.  It is important to note that this analysis was not part of the court’s separate consideration of the objective indicia of non-obviousness, though it sounds a lot like a long-felt, unmet need argument.  Rather, a lapse of time may now be relevant to the prima facie case of obviousness.