Storer v. Clark
860 F.3d 1340
Fed. Cir.2017Background
- This interference between Storer (Idenix; U.S. Patent No. 7,608,600) and Clark (Gilead) concerns methods of treating hepatitis C using nucleoside compounds specifically having a 2ʹ-fluoro ("down") substituent on a 2ʹ-fluoro-2ʹ-C-methyl nucleoside.
- Storer relied on an earlier-filed provisional application (S1, filed June 28, 2002) to claim priority; Clark filed later and challenged Storer’s entitlement to the provisional date.
- The PTAB held that the S1 provisional did not enable the claimed 2ʹF(down) compounds (and thus did not provide constructive reduction to practice) and awarded priority to Clark.
- Key factual findings: S1 contained generic formulas and synthetic schemes but no working examples of 2ʹF(down) compounds; prior art did not teach reliable fluorination of tertiary 2ʹ alcohols to give the down-fluoro stereochemistry; Storer’s team repeatedly failed in attempts and required extended experimentation.
- On appeal, the Federal Circuit affirmed, holding substantial evidence supports the Board’s conclusion that undue experimentation would be required to make the claimed 2ʹF(down) compounds from the S1 disclosure plus the prior art.
Issues
| Issue | Storer's Argument | Clark's Argument | Held |
|---|---|---|---|
| Whether S1 provisional + prior art enabled the 2ʹF(down) compounds (constructive reduction to practice) | S1 disclosed the target structures generically and, together with known prior-art precursors (e.g., Matsuda Compound 17) and common fluorinating reagents (DAST, Deoxo-Fluor), would allow a skilled artisan to make the compounds without undue experimentation | S1 lacked examples and taught schemes produced opposite stereochemistry; prior art did not reliably teach conversion to 2ʹF(down); significant unpredictable chemistry and failed attempts show undue experimentation required | Affirmed: S1 was not enabling; Storer not entitled to provisional priority date |
| Whether Board properly applied enablement standards (Wands factors) | Alleged Board undervalued that common methods and one-step fluorination would be predictable and sufficient | Argued Board correctly weighed Wands factors, including unpredictability, absence of working examples, and high level of experimentation | Affirmed: Board properly applied Wands factors and its factual findings are supported by substantial evidence |
| Relevance of third-party/industry success (Clark’s later synthesis) to enablement | Clark’s later successful synthesis shows the chemistry is predictable and would have been attainable from S1 + prior art | Clark’s success occurred with benefit of additional knowledge and hindsight; does not prove S1 alone enabled the compound | Affirmed: later success did not negate contemporaneous unpredictability or S1’s lack of guidance |
| Whether S1’s generic disclosure suffices for a genus that includes novel compounds | Generic structural disclosure + knowledge of art suffices if novel aspects are enabled; Storer claims disclosure was adequate | Novel stereochemical aspects and unpredictable transformations required more than generic disclosure and prior-art hints | Affirmed: generic disclosure did not supply the novel synthetic guidance required for enablement |
Key Cases Cited
- Biogen MA, Inc. v. Japanese Foundation for Cancer Research, 785 F.3d 648 (Fed. Cir. 2015) (AIA eliminated Section 146 district-court review for interferences declared after Sept. 15, 2012)
- Hyatt v. Boone, 146 F.3d 1348 (Fed. Cir. 1998) (earlier application must meet §112 enablement and written-description for interference subject matter)
- Microsoft Corp. v. Proxyconn, Inc., 789 F.3d 1292 (Fed. Cir. 2015) (enablement is a legal question reviewed without deference; underlying facts receive substantial-evidence review)
- In re Brebner, 455 F.2d 1402 (C.C.P.A. 1972) (for new chemical compounds, specification must enable production/synthesis)
- Streck, Inc. v. Research & Diagnostic Sys., Inc., 665 F.3d 1269 (Fed. Cir. 2012) (enablement requires practice without undue experimentation)
- ALZA Corp. v. Andrx Pharm., LLC, 603 F.3d 935 (Fed. Cir. 2010) (same enablement standard regarding undue experimentation)
- In re Wands, 858 F.2d 731 (Fed. Cir. 1988) (sets out the Wands factors for undue experimentation)
- Genentech, Inc. v. Novo Nordisk A/S, 108 F.3d 1361 (Fed. Cir. 1997) (specification must supply novel aspects of an invention; prior art cannot substitute for disclosure of novel elements)