Log in or register
Share on LinkedInShare on LinkedIn

ARTICLE · 26 OCTOBER 2026

Federal Circuit Affirms Written Description Support, Vacates Mooted Non-Obviousness Finding

Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Contributor
Finnegan, Henderson, Farabow, Garrett & Dunner LLP

Finnegan, Henderson, Farabow, Garrett & Dunner LLP

Finnegan, Henderson, Farabow, Garrett & Dunner LLP is one of the world’s largest firms focusing on...

View firm profile
Explore more from Finnegan, Henderson, Farabow, Garrett & Dunner LLP

The Federal Circuit affirmed a district court's validity findings for Exelixis's Salt Patents related to its cancer drug Cabometyx, holding that disclosure of chemical name, formula, and crystalline structure provided adequate written description support. However, the Court dismissed MSN's appeal and vacated the non-obviousness finding for the '349 Patent after Exelixis unilaterally dismissed its cross-appeal, preventing MSN from opposing the adverse judgment.

United StatesIntellectual Property
Joshua Sprague-Oliveira
Joshua Sprague-Oliveira
Christopher Anderson
Christopher Anderson
Erik Puknys
Erik Puknys
Author LinkedIn connections

In Exelixis, Inc., v. MSN Lab’ys Private LTD., No. 2025-1236 (Fed. Cir. Aug. 31, 2026), the Federal Circuit affirmed the district court’s validity findings regarding a group of asserted patents (the “Salt Patents”) and dismissed MSN’s appeal and vacated the underlying non-obviousness finding regarding the ’349 Patent.

Exelixis sued MSN for infringement of patents related to its kidney, liver, and differentiated thyroid cancer drug, Cabometyx®. In a bench trial, the district court found sufficient written description support for the asserted claims of the Salt Patents, to which MSN conceded infringement. The district court then found that the ’349 Patent was neither infringed nor invalid for obviousness. MSN appealed, challenging both validity findings. Exelixis cross-appealed as to the ’349 Patent noninfringement finding but later dismissed its cross-appeal, rendering this judgment of noninfringement final.

We operate a free-to-view policy, asking only that you register in order to read all of our content. Please login or register to view the rest of this article.

Register for freeORLog in

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

View source

Related Articles

Legal Intelligence Newsletters: sign up for the latest legal and regulatory news on your chosen topics

Read more about

Related Comparative Guides

See more popular content from

Article

UMG v. DistroKid: When AI Becomes A Consumer Protection Issue

Universal Music Group's lawsuit against DistroKid raises a critical question about AI disclosure in consumer markets: when does the use of artificial intelligence become material information that must be disclosed to consumers? The case centers on allegations that DistroKid distributed mass-generated AI music while creating the impression it was created by legitimate human artists, potentially violating existing consumer protection laws even without specific AI disclosure requirements.
United StatesIntellectual Property
Frankfurt Kurnit Klein & Selz PC
Frankfurt Kurnit Klein & Selz PC
Article

PTAB/USPTO Update - October 2026

The USPTO has released new templates and guidance for AIA trial proceedings, announced key appointments including a Chief AI Officer, and published updated procedures for patent applications and subject matter eligibility declarations. Director Squires delivered multiple addresses emphasizing the constitutional importance of intellectual property rights while the agency expanded its community engagement efforts and international collaboration through WIPO's Global IP Assignment Platform pilot program.
United StatesIntellectual Property
WilmerHale
WilmerHale
Article

The Trademark Scam Field Guide: Look-Alike Filing Sites, Fake USPTO Notices, And How To Get Out If You’ve Been Caught

A business decides to file a trademark. Someone on the team searches for a familiar online legal-services brand, clicks the first result, and lands on a site with a similar-sounding name, a polished design, five-star reviews, and a low flat fee. The application gets filed. Months later the business learns the “service” was not who they thought it was, the filing was signed by someone with no authority to sign it, and the USPTO has suspended the application along with hundreds or thousands of others from the same shop.
United StatesIntellectual Property
Harness IP
Harness IP
Article

Is This Real? Navigating AI Impersonation Under New And Existing Laws

Is this AI-generated, or is it real? As generative AI tools have become increasingly capable of creating realistic images, videos, and audio, they have also made it easier to impersonate real people without their consent. In response, states are increasingly adopting laws that impose civil and criminal liability for certain AI-generated content that replicates an individual’s identity, likeness, voice, or other personal attributes.
United StatesIntellectual Property
Wiley Rein
Wiley Rein
Article

Updates On Export Controls Impacting AI & Advanced Computing

The U.S. Department of Commerce's Bureau of Industry and Security issued guidance on May 31, 2026, clarifying licensing requirements for advanced computing items and AI technologies. The guidance maintains export restrictions for entities in certain countries while providing limited relief for data center operators, though questions remain about future regulatory direction. Companies must now strengthen their compliance programs and supply-chain due diligence as BIS continues to prioritize national security
GlobalInternational Law
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Article

Who Is A “Consumer?” The Supreme Court Takes Up The Video Privacy Protection Act

The Supreme Court will decide whether subscribing to any good or service from a video provider—such as a newsletter—makes someone a "consumer" under the Video Privacy Protection Act, or whether only subscriptions to audiovisual content qualify. The case involves allegations that a website disclosed a user's video-viewing history through Facebook tracking pixels after the user signed up for an online newsletter, creating a circuit split on how broadly the VPPA's consumer protections should apply.
United StatesPrivacy
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Article

Blaker V. NetScout Systems: A Narrow Reading Of The Pen Register And Trap And Trace Provisions Of The California Invasion Of Privacy Act In California State Court

On May 27, 2026, the Superior Court of California held that subdivision (a) of California Penal Code § 638.51 does not apply to software on commercial websites. Plaintiff Brian Blaker sued Defendant NetScout, Inc., alleging the Defendant had violated § 638.51 of the California Invasion of Privacy Act by implementing a software development kit (SDK) on its website.
United StatesPrivacy
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Article

D. Mass. Patent Litigation Update: August 2026

Recent patent litigation orders from the United States District Court for the District of Massachusetts reveal critical claim construction disputes and discovery rulings that shape the boundaries of patent enforcement. How do courts balance claim definiteness requirements with the practical realities of patent scope, and what standards govern third-party discovery in indirect infringement cases?
United StatesIntellectual Property
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Article

Federal Court Orders Rebel Creamery To Redesign Packaging And Disgorge $23.8 Million In Van Leeuwen Trade Dress Case

A New York federal court ruled that Rebel Creamery intentionally copied Van Leeuwen Ice Cream's distinctive packaging, resulting in a $23.785 million disgorgement order and mandatory redesign. The decision demonstrates how trade dress protection can extend to overall packaging aesthetics when individual elements combine to create a unique commercial impression, even when those elements might be commonplace in isolation.
United StatesIntellectual Property
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Article

Privacy Law Mid-Year Update: Key EU And UK Data Protection Decisions

Recent EU and UK court decisions have reshaped the landscape of data protection compliance, clarifying critical boundaries around consent, data subject rights, cybersecurity obligations, and children's privacy. These rulings demonstrate that organizations must move beyond formal compliance to embed proportionality, accountability, and risk-based decision-making into their data processing activities, even when disclosures are legally required or supported by valid legal bases.
GlobalPrivacy
Finnegan, Henderson, Farabow, Garrett & Dunner LLP
Finnegan, Henderson, Farabow, Garrett & Dunner LLP