In a decision denying institution of inter partes review rendered on February 5, 2020 , the Patent Trial and Appeal Board (“Board”) stated “there is no general rule that efficacy language in a claim is non-limiting.” Gilead Sciences, Inc. v. United States, IPR2019-01455, Paper 16 at 26.  The decision held, inter alia, that whether efficacy language in a claim should be given patentable weight is a fact-based inquiry that includes examining the application as whole and the patent record.  Id. at 26, 30.  When the claims at issue have been granted in a patent that issued from a continuation application, the patent record includes that of the parent patent (e.g., and, if applicable, any grandparent) or parent patent application.

The claims of U.S. Patent No. 9,937,191 (“’191 patent”) are generally directed towards processes for protecting a primate from infection by a self-replicating immunodeficiency retrovirus.  With these processes, protection is achieved by administering pharmaceutically effective amounts of a nucleoside reverse transcriptase inhibitor and a nucleotide reverse transcriptase inhibitor prior to exposure with the retrovirus.  The ’191 patent includes two independent claims – claim 1 recites as follows:

A process of protecting a primate host from a self-replicating infection by an immunodeficiency retrovirus comprising:

(a) selecting a primate host not infected with the immunodeficiency retrovirus, and

(b) administering directly to an uninfected primate host a combination comprising:

(i) a pharmaceutically effective amount of emtricitabine; and

(ii) a pharmaceutically effective amount of tenofovir or tenofovir disoproxil fumarate,

wherein the combination is administered orally in tablet form prior to the exposure of the primate host to the immunodeficiency retrovirus, thereby protecting the primate host from infection with the immunodeficiency retrovirus.

Articulating its analysis, the Board stated that “[w]e start with the language of the claims, including the preamble.”  Id. at 24.  The Board, quoting MBO Labs., Inc. v. Becton Dickinson & Co., 474 F.3d 1323, 1330 (Fed. Cir. 2007), explained “[a] claim’s preamble is limiting when it is ‘necessary to give life, meaning, and vitality to the claim.’”  Id.  In instances where the preamble is required for antecedent basis throughout the claim, such as the claims at issue in Gilead, “the preamble provides further meaning” regarding the scope of the claim, id., and is a “necessary component of the claimed invention.”  Id. at 24 (quoting Eaton Corp. v. Rockwell Int’l Corp., 323 F.3d 1332, 1339 (Fed. Cir. 2003)).  Gilead argued that “protecting a primate host from a self-replicating infection by an immunodeficiency retrovirus” and “thereby protecting the primate host from infection with the immunodeficiency retrovirus” is non-limiting and nothing more than an intended and inherent result of the operative steps of the claim.  Paper 16 at 22.  The Board disagreed, explaining that “[w]ithout the preamble and other allegedly non-limiting portions of the claims, sufficient context for [certain] language in the claims is lacking.”  Id. at 24.  Otherwise, “focusing on the ‘steps’ alone might be understood as vaguely directed to administering agents to a subject in unspecified amounts for an indeterminate objective.”  Id. at 24-25.      

Notably, the Board distinguished the facts of Gilead over Bristol-Myers Squibb Co. v. Ben Venue Labs., Inc., 246 F.3d 1368, 1375 (Fed. Cir. 2001), where “effective amount” language suggested no additional meaning nor implied any particular efficacy.  Unlike Bristol-Myers, where the specific dosages recited in the claims rendered the intended result superfluous, the efficacy language in Gilead provided necessary meaning to the claims.  Id.  Indeed, the Board noted that the specification recited the efficacy term, “protection,” well over thirty times.  Id. at 26.  “A specification ‘replete with references’ to preamble language may show the inventor regarded the language as ‘an important characteristic of the claimed invention.’”  Id. at 27 (quoting Poly-Am., LP v. GSE Lining Tech., Inc., 383 F.3d 1303, 1310 (Fed. Cir. 2004)).  Moreover, “protection” was key in the patent’s prosecution to overcome obviousness rejections.  Id. at 28.

Gilead thus provides practitioners additional guidance regarding the import of claim preambles and language that could be construed as intended use.