Magnitude of Comparative Results: What’s Considered Unexpected?

Posted by Jean Ge on Apr 24, 2017

The discovery of an optimum value of a “result-effective variable” in a known process is ordinarily considered within the skill of the art and obvious. But, if a patent owner shows that optimizing the variable resulted in benefits with a magnitude unexpected by one skilled in the art, the optimized variable may be found nonobvious, as in Coalition For Affordable Drugs v. Biogen Idec Inc. (IPR2015-01993).

The patent at issue in this IPR is directed to methods of treating multiple sclerosis by administering dimethyl fumarate (DMF), monomethyl fumarate (MMF) or a combination thereof, at a dose of 480 mg/day. Challenging the patent as obvious, the petitioner relied on the combined teachings of four prior art references to demonstrate that: (i) the use of DMF in treating multiple sclerosis was known in the art, albeit at a higher dosage (720 mg/day); and (ii) a person of ordinary skill in the art would have been motivated to conduct further tests to optimize the effective dose to minimize side effects. In the petitioner’s primary reference, a 720 mg/day dose of DMF was effective in reducing brain lesions caused by multiple sclerosis but had side effects, while a 360 mg/day dose was found ineffective against multiple sclerosis.

In response, Biogen provided post-filing data from two independent Phase III clinical trials to show that the therapeutic efficacy of 480 mg/day of DMF is essentially the same as that of 720 mg/day. Further, Biogen submitted testimony from several experts (the Board spent almost 6 pages of its opinion detailing the credentials of the experts) that one skilled in the art would have expected the efficacy of 480 mg/day to be closer to that of 360 mg/day, a dose which did not have a statistically significant effect, than to the therapeutically effective 720 mg/day. One expert stated, “It is stunning and unexpected to see, in two large independent studies, that increasing an ineffective dose (360 mg/day) by a small amount (120 mg/day) produces a strong therapeutic effect, and that a further, larger dose increase (to 720 mg/day) produces virtually no additional therapeutic benefits.”

Although the Board acknowledged that based on the teachings of the prior art one skilled in the art would have had ample reason to optimize the dose, it concluded that “obviousness is not established when the results of optimization are shown to result in property or benefit that a person of ordinary skill in the relevant art would have found to be unexpected.” So the Board found the petitioner did not meet its burden to show the challenged claims were unpatentable.


For both petitioners and patent owners, this case shows how unexpected results­­­—and even the magnitude of unexpected results—can make the difference between a patentable and unpatentable invention. Especially for patent owners, unexpected results, documented by expert testimony, may be another weapon to use when defending the patentability of an optimized variable, even if such unexpected results were not recognized when the application was filed.

Topics: Kyle Bass, BioPharma

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This blog is intended to promote thought and debate on developing areas of the law. The opinions, commentary and characterizations of cases provided on this blog are not legal advice and do not represent the opinions of Wolf Greenfield or its clients.