In Re Brana
51 F.3d 1560 (1995)
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Rule of Law:
A patent applicant can satisfy the utility requirement for a pharmaceutical invention by providing evidence of successful tests on standard experimental animals. The Patent and Trademark Office (PTO) has the initial burden of challenging an assertion of utility; only after the PTO presents evidence creating a reasonable doubt does the burden shift to the applicant to provide rebuttal evidence.
Facts:
- Miguel F. Brana and other researchers (applicants) developed new 5-nitrobenzo[de]isoquinoline-l,3-dione compounds intended for use as anti-tumor substances.
- The chemical structure of these compounds featured non-symmetrical substitutions, which distinguished them from prior art compounds with symmetrical substitutions.
- The patent specification asserted that these new compounds exhibited 'a better action and a better action spectrum as antitumor substances' than known compounds, specifically referencing a prior art publication by Pauli.
- The Pauli publication analyzed structurally similar compounds that had been tested for antitumor activity in vivo against two specific murine (mouse) lymphocytic leukemia models, P388 and L1210.
- The specification also included data from in vitro tests showing the cytotoxicity of the claimed compounds against human tumor cells.
- In correspondence with the patent office, the applicants submitted a declaration with test results showing their compounds were more effective in vitro against two human tumor cell lines than the symmetrically substituted compounds of the prior art.
Procedural Posture:
- Miguel F. Brana, et al. (applicants) filed a patent application with the U.S. Patent and Trademark Office (PTO).
- The PTO examiner initially rejected the claims as obvious under 35 U.S.C. § 103.
- After the applicants rebutted the obviousness rejection, the examiner withdrew it but issued a final rejection on other grounds.
- The applicants filed a continuation application, which the examiner again rejected in a final office action under 35 U.S.C. § 112, ¶ 1, for lack of utility.
- The applicants appealed the examiner’s final rejection to the PTO Board of Patent Appeals and Interferences (Board).
- The Board affirmed the examiner's rejection, adopting the examiner's reasoning.
- Miguel F. Brana, et al. (appellants) appealed the Board's decision to the U.S. Court of Appeals for the Federal Circuit, with the PTO Commissioner as the appellee.
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Issue:
Does a patent application for pharmaceutical compounds satisfy the utility and enablement requirements of 35 U.S.C. § 112, ¶ 1, when it discloses in vivo test data in animal models and compares the compounds to structurally similar prior art, without providing evidence of success in human clinical trials?
Opinions:
Majority - Plager
Yes. A patent application for pharmaceutical compounds satisfies the utility requirement by providing credible evidence of utility, such as successful in vivo animal tests, and does not require proof of efficacy in humans. First, the court found the specification alleged a sufficiently specific use. By referencing the Pauli article, which discussed tests on P388 and L1210 murine leukemia models, the applicants implicitly asserted utility against lymphocytic leukemia, a specific disease, thus distinguishing the case from precedents like In re Kirk where the disclosed utility was found to be too vague. Second, the court established a burden-shifting framework for utility. The PTO has the initial burden to provide evidence that would cause one of ordinary skill in the art to reasonably doubt the asserted utility. Here, the PTO failed to meet this burden, as the invention was not inherently unbelievable and prior art showed that structurally similar compounds were effective. Finally, the court held that even if the burden had shifted, the applicants provided sufficient proof of utility through in vivo test results on mice. The court explicitly rejected the PTO's conflation of the patent utility standard with the much higher FDA standard for approving drugs for human use, citing In re Krimmel to affirm that proving a 'desirable pharmaceutical property in a standard experimental animal' is a significant and useful contribution sufficient for patentability.
Analysis:
This decision solidifies the distinction between the legal standard for patent utility and the regulatory standard for FDA drug approval. It affirms that early-stage pharmaceutical inventions can be patented based on promising pre-clinical data, such as in vivo animal studies, without requiring costly and time-consuming human trials. The ruling protects inventors by placing the initial burden on the PTO to provide evidence-based reasons for doubting an invention's utility, preventing rejections based on mere skepticism. This framework encourages innovation and investment in pharmaceutical research by allowing companies to secure patent protection for promising compounds well before they are ready for the market.
