Immunogen, Inc. v. USPTO
Docket No. 2021-1939 (https://cafc.uscourts.gov/opinions-orders/21-1939.OPINION.3-25-2022_1926731.pdf) (Non-precedential)
NEWMAN, CLEVENGER, STOLL
March 25, 2022
Brief Summary: DC grant of SJ that Immunogen’s pending claims are indefinite and obvious vacated and remanded as factual findings not undisputed.
Summary: Immunogen appealed DC finding on summary judgment that the claims of its ‘809 patent application (‘809 Application) to methods of administering the anti-folate receptor immunoconjugate mirvetuximab for cancer are “fatally indefinite and fatally obvious”. The DC’s determination followed the USPTO Board affirmance of the examiner’s rejection of the pending claims for obviousness and obviousness-type double patenting. The claims require administration of the conjugate “at a dose of 6 [mg] of adjusted ideal body weight (AIBW) of the patient”, which is defined by the ‘809 Application as “a size descriptor that accounts for sex, total body weight, and height” and ideal body weight (IBW), “which is used to calculate AIBW, as ‘an estimate of weight corrected for sex and height, and optionally frame size’”. The ‘809 Application also incorporates by reference the Green and Duffull Br. J. Pharmacology publication (“Green”) as discussing AIBW and IBW in more detail (“Green discloses several methods for calculating IBW and lists correction factors, each specific to a different drug, that can be used to adjust IBW to AIBW.”) “The AIBW and IBW definitions” of the ’809 Application also “each include a formula, introduced by the phrase ‘for example,’” and Example 4 calculates AIBW “as the patient’s IBW plus 0.4 times their total (actual) body weight in kg minus their IBW” while IBW is defined for males “as 0.9 times their height in centimeters minus 88” and “for females…as 0.9 times their height in centimeters minus 92.” The FC panel opinion explains that “[t]he ‘0.4’ value in the AIBW formula is a specific correction factor for mirvetuximab, and is the only one presented in the ’809 Application.” SJ, the FC panel opinion explained, “is appropriate when, drawing all justifiable inferences in favor of the non-moving party, there exists no genuine issue of material fact and the moving party is entitled to judgment as a matter of law” (FRCP 56(c); Anderson, US 1986) and reviewed the DC decision under its Fourth Circuit law (“de novo, viewing all evidence in the light most favorable to the non-moving party”). And “[i]ndefiniteness and obviousness are both issues of law that may rely on underlying factual findings, such as the knowledge, level, or understanding of those skilled in the art” (BASF, FC 2017 and Teva, FC 2015 (indefiniteness); Acorda, FC 2018 (obviousness). The indefiniteness issue was first raised (properly under the rules) by the USPTO at the DC, which found the “‘for example’ language preceding the AIBW formula” left “a skilled artisan to wonder or to guess whether the formula provided is the only one covered by the ’809 Application” but the FC panel disagreed that view was undisputed as required at the SJ stage (e.g., “the USPTO never disputed” it until now). It similarly found the obviousness conclusion was not undisputed (e.g., whether the conjugate would cause ocular toxicity and other factual findings (secondary considerations)). The DC decision was therefore vacated and remanded.