Dimethyl fumarate – USA

Dimethyl fumarate – USA

On Nov. 30, 2021, Federal Circuit affirmed district court and found patent invalid under lack of written description support.



Biogen is the owner of US 8,399,514 patent entitled, “treatment for multiple sclerosis” expiring in Feb. 2028. This patent is listed in Orange Book for the product, Tecfidera® (Dimethyl fumarate/DMF) DR capsules. Mylan sought approval of generic version & thus filed ANDA containing P-IV certification with USFDA to US’514 patent. Biogen sued Mylan in Northern District of West Virginia. Based on the testimony offered at trial, the context of the ’514 Patent prosecution history, and “significant omissions from the specification,” the district court concluded that Mylan had satisfied its burden of showing by clear and convincing evidence that the asserted ’514 Patent claims were invalid for lack of written description under 35 U.S.C. § 112. You can read the summary here”.

Biogen appealed.



Federal Circuit said that the core issue in this appeal is whether the specification filed on February 8, 2007 supports the 2011 claims that issued in the ’514 Patent. Specifically, whether the original specification describes “possession” of the the therapeutically effective amount, 480 mg of DMF for treatment of Multiple Sclerosis (MS).” Federal Circuit presumably assumed that POSA would understand that the invention supports method of-treatment claims directed to MS with DMF. But with respect dose amount of 480 mg, Court opined that the specification’s sole reference to DMF 480 mg constitutes a significant fact that cuts against Biogen’s case. Moreover, DMF 720 mg, which is referenced independently as one dose and was known to be effective as of the February 2007 priority date. That Biogen later established the therapeutic efficacy of DMF 480 mg is of no import to the written-description analysis. Lukashev, the original inventor listed in the ’921 Application, offered testimony in which he “denied that his research could be extrapolated to a clinical dose of DMF; it ‘was never the focus of [his] work to inform the clinical dosing of DMF.’ Federal Circuit thus found no clear error in the district court’s judgment of invalidity.



Judge O’MALLEY in dissent said that the district court erred in applying judicial estoppel and it led to legal error in its interpretation of written description analysis. Specifically, the district court’s refusal to acknowledge the difference between “therapeutic effect” and “clinical effects” evinces a fundamental misunderstanding of what is claimed. Claims require therapeutic effect but district court applied stringent clinical effect theory. The district court’s failure to distinguish therapeutic effects and clinical efficacy also led it to conflate concepts of obviousness and written description…..”This conflation, in my view, caused the district court to erroneously require a showing of clinical data akin to what would be gathered in Phase III clinical trials in its written description analysis.” The district court’s conflation of therapeutic and clinical efficacy caused it to erroneously apply our “blaze marks” precedent. Notably, our “blaze marks” jurisprudence does not apply in every case concerning written description; it, instead, provides a useful framework to analyze whether written description has been met in cases involving patents containing laundry list disclosures. On reading of the ’514 patent, the district court erred as a matter of law by requiring Column 18 to contain sufficient “blaze marks” regarding the claimed DMF 480 mg therapeutically effective dose.


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