A recent decision of the US Federal Circuit court provides a timely example of the differences between Australian and American patent term extensions (PTE).
In 2015, we compared and contrasted patent term extension and supplementary protection certificates (PTEs) available in Australia, Europe and the USA, and concluded that, compared with Europe and the USA, although Australia provides an overall narrower basis for requesting a PTE, once granted, the protection afforded by an Australian PTE is greater than that of a European or an American PTE (Lyons and Stark, Pharm. Pat. Anal. (2015) 4(5), 351–355).
In Biogen International GmbH v. Banner Life Sciences, LLP, No. 1:18-cv-02054-LPS (D. Del. 2020), the Federal Circuit affirmed a lower court’s decision that “the scope of a patent term extension under 35 U.S.C. § 156 only includes the active ingredient of an approved product, or an ester or salt of that active ingredient”, and does not include an active agent produced in vivo from the active ingredient of the drug product that is the subject of the PTE.
Biogen’s drug product Tecfidera® is approved by the Food and Drug Administration (FDA) as a therapy for multiple sclerosis. Tecfidera® comprises dimethyl fumarate (DMF) as its active ingredient. DMF is a prodrug that is hydrolysed to the active agent monomethyl fumarate (MMF) upon ingestion. MMF is the active ingredient of Banner’s drug product Bafiertam™.
Importantly, as noted previously (Lyons and Stark), an American PTE is limited to the drug product for which marketing authorisation has been granted.
Based on the FDA’s approval of Tecfidera®, Biogen obtained a PTE for US 7,619,001 covering a method of treating multiple sclerosis comprising administering DMF, MMF, or a combination thereof. Biogen then asserted the patent against Banner during the PTE period alleging Banner had infringed the patent by applying for FDA approval of Bafiertam™ for treating multiple sclerosis and would continue to infringe the patent by sale of Bafiertam™ for that use.
Although using MMF to treat multiple sclerosis appears to infringe Biogen’s patent on face value, the court was tasked with deciding whether any infringement occurred during the PTE period. The court was not swayed by Biogen’s argument that during the PTE period, the scope of the claims included any derivative product with the same pharmacological action or even the active agent produced from a prodrug. Instead, as suggested above, the court held that Bafiertam™ did not fall within the scope of the claims during the PTE period, because during the PTE period, the scope of the claims is limited to the active ingredient (DMF) of an approved product (Tecfidera®) or an ester or salt of that active ingredient, none of which defined MMF.
In comparison, if the same circumstances arose in Australia, PTE would not have been granted because PTE cannot be based on a method of treatment. PTE can only be based on a “pharmaceutical substance per se” or a “pharmaceutical substance when produced by a process that involves the use of recombinant DNA technology”.
Putting that aside, had an Australian PTE been granted based on Tecfidera®, Bafiertam™ comprising MMF would have infringed the claims of the patent during the PTE period. This is because under Australian legislation, during the PTE period, the claims cover any product put to human therapeutic use falling within the scope of the claims, i.e. the PTE is not limited to the drug product upon which the PTE was granted.
This subtle yet significant distinction combined with Australia’s universal healthcare and pharmaceutical reimbursement systems should prompt owners and/or sponsors of drug products considering PTE in the USA to consider obtaining PTE in Australia also.
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