Introduction

On June 28, 2018 the Court of Appeals for the Federal Circuit (“Federal Circuit”) has decided Impax Laboratories Inc. v. Lannett Holdings Inc. Licensed to Impax Laboratories Inc. (“Impax”) by AstraZeneca UK Limited (“AstraZeneca”), Zomig® Nasal Spray, made from AstraZaneca’s patented zolmitriptan formulation, was developed and sold for migraine treatment. In June 2014, Lannett Holdings Inc. (“Lannett”) notified AstraZeneca of its pursuit of developing a generic version of Zomig® Nasal Spray, alleging noninfringement and invalidity of AstraZeneca’s patents as obvious over prior art disclosing a formulation that could be administered intranasally, further suggesting that zolmitriptan could be an active ingredient in the formulation. In defense Impax sued Lannett in the District of Delaware for infringement, and the court ruled in favor of Impax, asserting that the prior art taught away from intranasal application as zolmitriptan alone is not an active ingredient for such application, which is required of intranasal administration. Lannett appealed the court’s decision, and the case was brought to the Federal Circuit.

Decision & Conclusion

While the Federal Circuit found the case “close,” the district court’s findings were affirmed. One skilled in the art would be dissuaded from an intranasal application of zolmitriptan as it is “absolutely counterintuitive to make a nasal spray when you have an active metabolite which is more potent...than the drug itself” (13). As such, the prior art failed to teach the administration of zolmitriptan through the nasal passage. Furthermore, “The court found Appellees’ experts more credible than Lannett’s and ultimately was not convinced that Lannett had shown that the patents were invalid” (16). Thus, patent claim invalidation cannot be supported by prior art’s mere mentions of a claimed formulation and the administration of this formulation when the ingredient in question is only part of the claimed formulation rather than its active ingredient.

Full Impax Laboratories Inc. v. Lannett Holdings Inc. can be read here: http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/17-2020.Opinion.6-28-2018.pdf