In Impax Laboratories Inc. v. Lannett Holdings Inc., [2017-2020] (June 28, 2018), the Federal Circuit affirmed the district court decision that claims 4, 11, 12, and 14 of U.S. Patent 6,760,237 and claims 6 and 14–16 of U.S. Patent 7,220,767 were not shown to be invalid and entering an injunction.
The claims at issue are directed to pharmaceutical formulations, intranasal administration devices, or aqueous solutions, of zolmitriptan. The Federal Circuit noted that all of the claims at issue rise and fall together with the issue of whether it would have been obvious to make zolmitriptan into a nasal spray.
In considering the asserted obviousness of the claimed invention, the Federal Circuit noted that while the reference mentioned the possible nasal administration of zolmitriptan (just once, and not in a claim or an example), the reference was not about administering zolmitriptan, but about the nasal administration of active ingredients generally. The Federal Circuit also noted evidence in the record that a skilled artisan would have expected delayed or lower therapeutic effectiveness from zolmitriptan if administered nasally because it would have been “absolutely counterintuitive to make a nasal spray when you have an active metabolite which is more potent . . . than the drug itself.”
The Federal Circuit said:
In view of the totality of the record evidence of the state of the prior art, we cannot find that the district court clearly erred in its findings. Far from disregarding the prior art’s discussion of zolmitriptan, the court specifically considered and acknowledged that zolmitriptan was mentioned in connection with nasal formulations and sprays. However, the court also properly considered additional record evidence to make findings on the state of the prior art as a whole.
The Federal Circuit noted that the presence or absence of a motivation to combine references in an obviousness determination is a pure question of fact, as is what a reference teaches and whether it teaches toward or away from the claimed invention. Based on the record before it, the Federal Circuit could not find that the court clearly erred in concluding that, at the time, zolmitriptan’s known significant reliance on its active metabolite would have, on balance, dissuaded a person of skill in the art from making nasal formulations of zolmitriptan. The Federal Circuit said that it does not and should not reweigh evidence or make factual findings anew on appeal.