Someone walks into your office and asks: Is it possible to patent a combination of known compounds based on an unexpected synergy between them?  The answer remains ‘yes,’ and you should consider citing Sanofi-Aventis v. Glenmark in support.

In Sanofi, decided last month by the Federal Circuit, the patentee discovered that a combination of two active ingredients in a single dosage provided longer-lasting control than previously known treatments.  When generic drug makers submitted an Abbreviated New Drug Application seeking permission to market this combination before the expiration of the patent, the owner and licensees of the patent sued for infringement.

The accused infringers argued that the patent was invalid on grounds of obviousness: Each ingredient, they said, was known to be effective for treating hypertension such that the combination of these ingredients would have been “obvious to try.”

The defendants further contended that any advantages from the obvious combination were merely unknown benefits that were not recognized at the time of filing.

The Federal Circuit reasoned that “it would not be ‘obvious to try’ when ‘the prior art gave either no indication of which parameters were critical or no direction as to which of many possible choices is likely to be successful.’”

Regarding unexpected results, the Federal Circuit reiterated the principle that “patentability may consider all of the characteristics possessed by the invention, whenever those characteristics become manifest.”  This means that unexpected results discovered after the filing date or even issue date of a patent can weigh against a finding of obviousness.

The court concluded the obviousness discussion by finding that a jury could have reasonably concluded that a person skilled in the art would not have predicted the longer-lasting hypertension control.

This case affirms the patentability of combination inventions based on unexpected results, regardless of when those unexpected results become known.  The ruling should also be considered when addressing arguments that a claim was “obvious to try” or that unexpected results were not presented in the originally filed specification.