No Enablement of a “Make and Screen” Invention Where Working Examples Do Not Represent Diversity of the Claimed Genus

Feb 24, 2022

Reading Time : 2 min

Claim 1 of the asserted patent in this case was directed to a genus of antibodies defined by two requirements—an isolated antibody or antibody fragment (1) “binds Factor IX or Factor IXa” and (2) “increases the procoagulant activity of Factor IXa.”

In reaching its decision, the court first walked through the Wands factors and found the number of potential candidate antibodies that could fall within the scope of the claim was potentially in the millions, and that screening was required at every “critical step” to determine whether antibodies fall within the claims. The court further found that there were few working examples in the specification and little guidance for how to identify which candidates satisfy the claim. The court deemed the field of antibodies unpredictable, and found the lack of guidance compounded the unpredictability.

Based on its review of the Wands factors, the court dubbed the technology a “make and screen invention,” where suitable antibodies could only be discovered through trial and error. The court discounted the patentee’s argument that the claimed genus contains few antibodies, finding the disparity between the number of possible candidates and the number of claimed antibodies weighed in favor of no enablement. The court reasoned “[t]hat there are fewer needles in the haystack makes the search harder, not easier.”

The court also gave little credit to the patent’s teachings regarding how screening should be performed to identify suitable antibodies, finding that even if such screening had become routine, the teachings still required someone to repeat the same process the inventors used in the first place.

Next, the court noted that although the claims covered antibodies having a wide range of efficacies, there was no indication that antibodies were made or could have been made that achieved the highest levels of efficacy. The court appeared particularly persuaded by two facts. First, the accused infringer took almost 10 years to develop the accused product, which achieved better activity than any antibody disclosed in the patent, but was still far lower than normal levels. Second, the patentee never brought a product to market that embodied the claimed invention. In fact, one of its experts eventually conceded that the patent’s description of therapeutic utility was aspirational, and that it would be difficult or impossible to create an antibody that increased activity back to normal levels.

Finally, the court noted that the working examples in the patent were limited to mouse monospecific IgG or IgM antibodies, which made up only a small subset of the broad antibody structures the claim covered. The court noted that the specification “does not remotely enable the accused antibody,” a bispecific antibody that plaintiff alleges falls within the claims. The dependent claims fared no better—some of them limited the genus to specific structural features for which there were zero examples.

The court concluded that the patent owner merely provided a starting point for further research, but was attempting to claim someone else’s solution.

Practice Tip: Patent Owners should pursue a range of genus claims, some tailored specifically to the working examples in the patent and, in response to an enablement challenge, should highlight any teaching in the patent that provides a shortcut in development, whether it be structural features of relevant compounds or manufacturing techniques that can be used with some expectation of success. For patent challengers, this case reinforces that it can be important to establish the breadth of claims and the degree of trial and error required to identify candidates that fall within a genus.

Baxalta, Inc. v. Genentech, Inc., 1:17-cv-00509 (D. Del. Jan. 13, 2022)

Share This Insight

Previous Entries

IP Newsflash

December 3, 2025

The Federal Circuit recently held that a patentee acted as its own lexicographer to define a claim term even though it did not explicitly define the term. Rather, because the patentee consistently and clearly used two terms interchangeably to describe the same structural feature and did so in all of the embodiments in which the feature appeared, the patentee impliedly gave the term its own, unique definition.

...

Read More

IP Newsflash

December 2, 2025

The Federal Circuit recently held an asserted patent was not entitled to its priority date because the priority application lacked written description support for the asserted claims. In so doing, the court explained that broad disclosures that do not provide reasonably specific support for narrower claims do not meet the written description requirement. The court also considered whether the inventor’s testimony showed they possessed the full scope of the claimed genus at the priority date or whether it was more likely the inventors first became aware of the claimed embodiments from public disclosures of the accused product.

...

Read More

IP Newsflash

December 1, 2025

In a Hatch-Waxman case, the District of Delaware denied a motion for summary judgment seeking to apply the ANDA filing date as the date of the hypothetical negotiation used to calculate reasonable royalty damages. Instead, the court determined that the appropriate date to use for the hypothetical negotiation is the launch date.

...

Read More

IP Newsflash

November 17,2025

The district of Delaware recently denied a defendant’s partial motion to dismiss pre-suit willful infringement from the litigation, finding instead that the allegations taken as a whole were sufficient to support pre-suit willfulness at the pleading stage. Specifically, the court found that the allegations as to the defendant’s involvement in a related foreign opposition proceeding and participation in the relevant industry were accompanied by detailed factual support that sufficiently pleaded willful infringement for the pre-suit period.

...

Read More

© 2025 Akin Gump Strauss Hauer & Feld LLP. All rights reserved. Attorney advertising. This document is distributed for informational use only; it does not constitute legal advice and should not be used as such. Prior results do not guarantee a similar outcome. Akin is the practicing name of Akin Gump LLP, a New York limited liability partnership authorized and regulated by the Solicitors Regulation Authority under number 267321. A list of the partners is available for inspection at Eighth Floor, Ten Bishops Square, London E1 6EG. For more information about Akin Gump LLP, Akin Gump Strauss Hauer & Feld LLP and other associated entities under which the Akin Gump network operates worldwide, please see our Legal Notices page.