To satisfy the enablement requirement applicants should provide the explicit examples of the claimed compound or direction or guidance on how to synthesize the claimed compound. Disclosing generic structure or general approaches to synthesis does not by itself satisfy the enablement requirement for specific compound. A known precursor does not enable synthesis of a claimed compound if the application does not disclose the precursor or how to convert it into a claimed compound.
On June 21, 2017, the Federal Circuit affirmed a Patent Trial and Appeal Board’s interference decision, which awarded priority to Clark’s pending application (filed May 30, 2003) over Storer’s issued patent. The Court found that Storer’s earlier provisional application (filed June 28, 2002) did not enable the subject matter of Storer’s interfering claims.

Storer vs. Clark
Storer and clark both claimed a method of treating Hepatitis C using modified nucleoside compound, including heterocyclic compound having fluorine substitute. Clark filed a motion to deny Storer the benefit of its provisional application and to invalidate Storer’s priority claims based on lack of enablement. The PTAB held that the Storer’s provisional application together with prior art did not enable specific compound claimed and it awarded priority to Clark. Storer appealed. The only question on appeal was whether Storer’s provisional application enabled compound having fluorine substituent.

Earlier filing benefits
When a party to interference seeks to benefit from the filing date of an earlier application, the earlier application must meet the requirements of section 35 U.S.C.120, and written the description, enablement, and best mode requirement of 35 U.S.C. 112. To stablish enablement of the claim that uses new chemical compound to treat disease, the application must enable protection and synthesis of the new compound. The enablement requirement is met when one skilled in the art, having read the specification, can practice the invention with “undue – experimentation”.

Complete specification not provided
The Court found that there was substantial evidence to prove the Board’s finding that a person of ordinary skill in the art, using disclosure in the provisional application and the knowledge of the prior art would not have been able to make a compound with claimed fluorine substituent without undue experimentation. The Storer’s application provided two general approaches, but provided no synthesis method of the target compound. The court noted that the Storer and his team were unable to synthesize the target compound even after filing the provisional application and that the expert’s in the field were skeptical of Storer’s invention.

Storer argued that the prior art contained in the “ Well known precursor compound that is only one step away from target compound and the precursor together, with the Storer provisional, enabled synthesis of the claimed compound . However, the Storer provisional did not mention the precursor and did not show how to convert precursor into claimed structure. Viewing all the evidence, the court agreed with the Board that the provisional application did not teach or suggest conversion of any precursor into claimed structure and that the precursor did not enable one skill in the art to produce the claimed compound without undue experimentation.