By Kevin M. Repper
In the case of AstraZeneca Pharmaceuticals LP v. Apotex Corp., No. 2011-1182 (Fed. Cir. 2012), Astrazeneca holds the rights to three patents related to the drug rosuvastatin calcium. Two of the three patents involve methods of using rosuvastatin compounds. One of which is a method of treating heterozygous damilial hypercholesterolemia (HeFH) and the other is a method of lowering cardiovascular disease risk for individuals who have normal cholesterol levels but demonstrate elevated circulating C-reactive protein (CRP). The method of use patents expire in 2021 and 2018, respectively.
Apotex, a generic pharmaceutical manufacturer, filed an Abbreviated New Drug Applications (ANDA) with the FDA seeking to market generic rosuvastatin for treating hypercholesterolemia (HoFH) and hypertriglycerdemia while omitting or “carving out” patented indications directed towards the treatment of HeFH and elevated CRP. Under the Hatch-Waxman Act, the filed ANDA must provide a list of all the related patents and if the method of use patents do not claim a use for which the applicant is seeking approval, an applicant may instead submit a statement under 21 U.S.C. § 355(j)(2)(A)(viii) averring that the ANDA excludes all uses claimed in the patent (Section viii). Apotex properly submitted the Section viii statements regarding Astrazeneca’s method patents.
Astrazeneca brought an action against Apotex alleging that Apotex’s ANDAs, as filed, violated § 271(e)(2) because the use of the drug is claimed in AstraZeneca’s method patents. According to § 271(e)(2), “it shall be an act of infringement to submit an application…for a drug claimed in a patent or the use of which is claimed in a patent…if the purpose of such submission is to obtain approval under such Act to engage in the commercial manufacture, use, or sale of a drug…claimed in a patent of the use of which is claimed in a patent before the expiration of such patent.” Astrazeneca argued that because their method patents claim any use of the drug, Apotex’s filed ANDA falls within the meaning of § 271(e)(2) and has infringed on their patents.
However, the court took a different stance. The court understood the term “use” from § 271(e)(2) to mean “the use listed in the ANDA.” Accordingly, the court held that it is not necessarily an act of infringement under § 271(e)(2) to submit an ANDA for a drug if just any use of that drug is claimed in a patent; rather, infringement of method claims under § 271(e)(2) requires filing an ANDA wherein at least one “use” listed in the ANDA is claimed in a patent. The court concluded that there can be no cause of action for infringement of a method of use unless the accused ANDA actually seeks approval for a patented indication.
An obvious solution for patent holders is to patent the drug itself. Astra has a patent that claims rosuvastatin compounds and pharmaceutical compositions containing such compounds, however the patent was due to expire years prior to the expiration of the method patents. Also, Apotex is challenging the validity of the composition patent in another co-pending litigation. Other solutions may include determining as many methods of treatment for as many diseases as you can and patenting those methods. This however takes a lot of time and a lot of resources.
Another possible option would be to patent the method of what the drug actually does in the body in addition to the disease that the drug treats. For example, rosuvastatin calcium serves to reduce circulating cholesterol by competitively inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase. A patentable method claim of rosuvastatin calcium could have been a method of inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase. This method claim would likely be broad enough to cover most methods of treatment of any particular disease, especially if the diseases were listed the specification. Therefore, the court may have ruled that the use was in fact covered by the claims.