In the recent Braintree Labs v. Novel Labs, the Federal Circuit may have limited the value of composition for methods of treatment claims.  The patent-in-suit related to compositions for preparing the bowels of a patient ready for colonoscopy.  In particular, the claims were to a bowel prep composition “for inducing purgation of the colon of a patient” so as not to cause any clinically significant electrolyte shifts.

One issue on appeal was the construction of the term “a patient.”  The district court interpreted “patient” to mean “one or more patients.”  On that basis, it found that the defendant Novell infringed the claims because at least one patient to whom the composition was given had not experienced clinically significant electrolyte shifts.  On appeal, Novell argued that this construction was wrong because it would allow a composition to meet the requirements of the claims even if 99 patients out of 100 patients experienced clinically significant electrolyte shifts; that is, there would be infringement even if only one patient did not.  Judge Prost, with Judge Dyk joining, agreed with Novel and interpreted “a patient” to mean the general class of persons to whom the patented compositions are directed, i.e., a patient population.  The majority reasoned that the district court’s erroneous interpretation “leads to the absurd result of infringement even if a composition causes clinically significant electrolyte shifts in a large percentage of patients.”  The infringement ruling was thus vacated, and the case remanded to the district court to determine whether the ANDA product would result in a lack of clinically electrolyte shifts in the patient population as a whole.

Judge Moore dissented as to the majority’s construction of “a patient.”  She wrote that the plain meaning of “a patient” is one or more patients.  Acknowledging the majority belief that to rule otherwise would lead to an “absurd result,” Judge Moore said that the majority’s concern was one relating to damages, not to infringement.  She stated that infringement of such a small scale, for example, in only one out of a 100 patients, would result in commensurately limited damages.  That this was a Hatch-Waxman case pre-launch of the generic drug was simply too bad for the generic company in her opinion.  The proper remedy to avoid the “absurd result” referenced by the majority would be for Congress to amend the Hatch Waxman Act.

The claim language at issue in this case is typical in pharmaceutical patents.  Claims are often written in a way such that a composition achieves a particular result in “a patient.”  The takeaway from this case is that, in such a case, there is now precedent for a claim construction requiring that the claimed result occur in the patient population generally, as opposed to only one patient or a small percentage of patients.  The problem with this decision is that it gives no guidance as to where the line is between the general patient population as a whole and what constitutes less than the general patient population.  It will be up to district court judges to draw these lines for the time being.