For non-functional claim limitations, providing a description by structure and process of creation that matches the claimed term is sufficient to satisfy the written description requirement.

Background / Facts: The patent being asserted here is directed to the chemical compound dutasteride, which has been proven effective in treating benign prostatic hyperplasia, otherwise known as enlargement of the prostate gland. The patentee markets Avodart® and Jalyn™, which contain dutasteride and are approved by the FDA to treat symptoms of benign prostatic hyperplasia. The asserted claims cover not only dutasteride, but also any pharmaceutically acceptable “solvate” thereof. A “solvate,” by definition, is something that originates in a “solution,” which is a mixture of two substances: a “solute” dissolved in a “solvent.”

Issue(s): Whether, under what is now 35 U.S.C. § 112(a), the written description adequately supports the claims to “solvates” of dutasteride.

Holding(s): Yes. “The Detailed Description provides a description by structure and process of creation that matches the claimed term.” “We have no precedent under which this two-condition description, matching the claim scope, would be insufficient. To the contrary, this court has repeatedly ‘explained that an adequate written description requires a precise definition, such as by structure, formula, chemical name, physical properties, or other properties, of species falling within the genus sufficient to distinguish the genus from other materials.’ … Describing a complex of dutasteride and solvent molecules is an identification of ‘structural features commonly possessed by members of the genus that distinguish them from others,’ allowing one of skill in the art to ‘visualize or recognize the identity of the members of the genus.’ … Critically, moreover, the claim term at issue, ‘solvate,’ is not functional: to be a ‘solvate,’ a compound need not produce a desired result or otherwise perform a certain function. The claim term and its corresponding description, however broad, identify certain structures produced by certain processes. We have not required more for an adequate written description that matches claim scope.”

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