Overview
Ari Feinstein’s practice focuses on patent litigation, trademark litigation, and trademark oppositions.
Ari has experience working on intellectual property adversarial matters in a wide variety of industries, including consumer electronics, pharmaceuticals, medical devices, food and beverage, fitness and nutrition, semiconductors, HVAC, and hydrometallurgy.
Ari is also committed to pro bono service, leading a team from the firm that represents survivors of domestic violence seeking civil protection orders from the D.C. Superior Court in partnership with Volunteer Legal Advocates (VLA). In recognition of this work, he received VLA’s 2025 Civil Protection Order Volunteer of the Year award.
During law school, Ari was an executive editor and later the Managing Editor of the Journal of Law and Technology. He also participated in the school’s Patent & Licensing Clinic. Ari’s undergrad studies focused on chemistry.
Education
- University of Virginia School of Law (J.D., 2017), Virginia Journal of Law and Technology, Managing Editor
- Case Western Reserve University (B.A. Chemistry, 2011), cum laude
Representative Experience
Alcon Inc. et al. v. Padagis Israel Pharmaceuticals Ltd. et al., 22-cv-01422-WCB (D. Del.) (2025)
Represented Padagis in Hatch-Waxman litigation in the District of Delaware concerning patents related to Simbrinza® (a glaucoma treatment). After a three-day bench trial, U.S. Circuit Judge William C. Bryson, sitting by designation, found that Padagis’s product did not infringe the remaining patent-in-suit. Alcon had originally asserted two patents, but stipulated to non-infringement of the second patent after summary judgment was granted in favor of Padagis on multiple issues.
Public Storage v. Charles D. Burrus Family Trust d/b/a Mini Public Storage, 8:23-cv-01190 (C.D. Cal. 2024)
Represented Public Storage in a trademark infringement and unfair competition action relating to self-storage rental services. Successfully moved for summary judgment on Public Storage’s claims and successfully cross-moved for summary judgment on all remaining defenses, including laches.
Novo Nordisk Inc. et al. v. Orbicular Pharmaceutical Tech. Pvt. Ltd. et al., 22-00856 (D. Del. 2024)
Represented the Cipla and Orbicular defendants in a patent infringement action on patents relating to injection devices and GLP-1 agonist formulations (used in Novo’s Saxenda® and Victoza® products). Obtained a favorable case-dispositive settlement for client prior to trial.
Belparts Group, N.V. v. Belimo Automation AG et al., 3:21-CV-00334 (D. Conn. 2022)
Represented Belimo in a patent infringement action relating to automatic electronic control valves used in HVAC systems. Obtained a favorable case-dispositive settlement.
Vocalife LLC v. Amazon.com, Inc. et al., 2:19-CV-00123 (E.D. Tex.), rev’d, No. 2021-1937 (Fed. Cir. 2022)
Represented Amazon in a patent infringement action relating to the Amazon Echo devices. After a jury verdict that a patent on a microphone system was infringed by the sale of Amazon’s Echo products, the Knobbe Martens team obtained a complete reversal that the Amazon Echo devices do not infringe any patent claim.
Pacific Packaging Concepts, Inc. v. Nutrisystem, Inc. et al., 2:19-cv-04755 (C.D. Cal. 2022)
Successfully enforced Pacific Packaging’s FRESH START trademark against Nutrisystem resulting in favorable settlement.
Vital Pharmaceuticals, Inc. v. Monster Energy Co. et al., 553 F. Supp. 3d 1180 (S.D. Fla. 2021), aff’d, No. 21-13264 (11th Cir. 2022)
Successfully defended Monster Energy in a trademark and trade dress infringement action. After a bench trial, obtained a judgment of no trade dress infringement by selling the REIGN energy drinks. On appeal, obtained an affirmance that the district court did not deny plaintiff its right to trial by jury.
In re Sleep-Disordered Breathing Treatment Mask Systems and Components Thereof, USITC Inv. No. 337-TA-1134 (2019)
Represented Fisher & Paykel Healthcare in action before the International Trade Commission relating to patient interfaces for sleep apnea therapy.
King v. O’Rourke, Case No. 17-4433 (2018):
Represented American Service Veteran in Appeal from the Board of Veterans’ Appeals for denial of service benefits to the United States Court of Appeals for Veterans Claims. Successfully obtained favorable remand for Veteran.
Recognition
Awards & Honors
- Recognized in Best Lawyers: Ones to Watch for Intellectual Property Law (2025-2026)
- Named to Benchmark Litigation “40 & Under” List (2026)
News & Insights
Articles
Co-Author, “How US courts are addressing fair use questions in AI training and copyright disputes,” IAM (June 2026)
Co-Author, “An Examination of the Impact of Chevron’s Death on Certain Intellectual Property Laws,” Intellectual Property & Technology Law Journal (January 2025)
Co-Author, “Patent Venue, and How It Works in Abbreviated New Drug Application Litigation,” Intellectual Property & Technology Law Journal (October 2023)
Co-Author, “Federal Circuit: Trademark Decisions Rendered by International Trade Commission Do Not Have Preclusive Effect,” World Trademark Review (May 20, 2019)
Co-Author, “The Supreme Court Holds that Non-Public Sales May Trigger the “On Sale” Bar Under the America Invents Act,” Knobbe Martens Firm Alert (January 22, 2019)
Co-Author, “Patent Protection for Cannabis?,” Pharmaceutical Executive (November 12, 2018)
Co-Author, “Intellectual Property in Nutraceuticals: Patents, Trademarks, and Trade Secrets,” Nutritional Outlook (August 14, 2018)
Co-Author, “Supreme Court to Review Post-AIA-On-Sale Bar,” Intellectual Property Strategist (August 2, 2018)
Litigation Blogs
- The Problem with Defining the “Problem”: Federal Circuit Affirms Flexible Analogous-Art Analysis
- Skinny Labels at the Supreme Court: Carving Out Room for Generics to Breathe
- Standing Still? Only if Injury-In-Fact Is Tied to the Claims at Issue
- The Credibility of Experts Is in the Province of the Jury
- Presented by Netflix—Grammar Police: An Exercise in Claim Construction
- Challenged Director-To-PTAB Instructions Did Not Require Notice-And-Comment Rulemaking
- Defeating the Duo: Jumping to Alice Step Two
- No Kitchen Confusion: When Comparing Marks, the Trademark Board Can Give Less Weight to Shared Terms if the Terms Are Suggestive or Descriptive
- Imaginary Slice of Accused Product Failed to Satisfy Structural Claim Limitation
- Non-Infringement Need Not Be “Actually Litigated” to Shield Accused Products From Infringement Liability in Subsequent Actions
- Do Not Bank on a Bank Not Being a “Person” Under the AIA
- Non-Prior Art Evidence May Be Used to Prove Inherency
Biotechnology Blog
- No “Duty to Innovate” – California’s Highest Court Finds Gilead Sciences Not Negligent for Delaying Release of Allegedly Safer HIV Drug
- Proposed Legislation to Codify “Skinny Label” Safe Harbor
- New FDA Program Prioritizes Review of Certain ANDAs
- Edwards v. Meril at the Supreme Court: Testing the Scope of Hatch-Waxman’s Safe Harbor
- “Improper” Listing of Patents in the FDA’s Orange Book
- Antitrust Lawsuit Brought Against Drug Manufacturer Based on Its Allegedly Improper Listing of Device Patents in the FDA’s Orange Book
- Shire v. Blackburn: Drawing the Line Between FDA Drug Labeling Regulations and State Law on Product Liability
- Teva v. GSK: The “Skinny” Label Case Pending Before the Supreme Court
Trademark & Brand Protection Blog
