Skip to main content

Justin J. Leisey


[email protected]



Justin is a registered patent attorney with a background in chemical engineering. He drafts and prosecutes U.S. and foreign patent applications for clients in a variety of industries, including the life sciences, medtech, pharmaceuticals, clean tech, energy and sustainability, manufacturing, LED and lighting design, and mechanical devices.

Justin also conducts patent searches and drafts invalidity/infringement and patentability opinions, assesses risks associated with freedom to operate issues, prepares landscape analyses and competitive intelligence reports, and identifies whitespace opportunities. His work also includes performing due diligence on third-party intellectual property, reviewing and drafting IP provisions of transactional and licensing agreements, and supporting patent litigation, inter partes review, and interference matters.  He maintains an active pro bono practice that advises clients on all forms of intellectual property protection.

Prior to joining Mintz, Justin was an associate in the San Diego and Boston offices of a large, international law firm. He also worked as intellectual property counsel for a manufacturing company that produces optical films and photovoltaic lenses. In addition, he has taught executive-MBA class sessions on protecting intellectual property and counsels startup companies at San Diego State University. 

Justin began his professional career as a process engineer and has worked extensively in manufacturing environments before becoming a patent attorney.  He has experience patenting technologies including drug delivery polymers, biodegradable polymers, polymer processing, inorganic catalysts, nutraceuticals, syringes, endoscopes, laparoscopic staplers, medical devices, lithium-ion batteries, ultracapacitors, electronic devices, led lighting, engineered fuels, graphene composites, liquid-impregnated surfaces, microtrenching equipment,  rotary/linear actuators, basalt fibers, cloud services, and variable data printing.


  • University of Connecticut (JD)
  • Virginia Polytechnic Institute & State University (BS, Chemical Engineering, cum laude)


Intellectual Property Viewpoints Thumbnail

How NFTs and Blockchain Secure Digital Sports Collectibles

May 24, 2021 | Blog | By Keith P. Carroll, Andrew D. Skale, Justin J. Leisey

Today, there are new opportunities to own a bit of sports history. It is now possible to even own a digital collectible of your favorite athlete making a play during a game.  NFTs (non-fungible tokens) are being used to provide digital provenance that affords unique ownership of sports most memorable moments. 
Read more
Patent Prosecution and Strategic Counseling Viewpoint Thumbnail

Obviousness-Type Double Patenting and Divisional Applications in Canada

March 23, 2021 | Blog | By Andrew D. Skale, Justin J. Leisey

Obviousness-type double patenting (“OTDP”) arises when two or more patents or applications include claims that, while not being identical, are not patentably distinct from each other.  In the U.S., OTDP rejections can be overcome by filing a terminal disclaimer that limits the term of the rejected application to be no greater than the term of the disclaimed patent. 
Read more
Patent Prosecution and Strategic Counseling Viewpoint Thumbnail

Understanding Chinese Voluntary Divisional Application Patent Practice

February 10, 2021 | Blog | By Andrew D. Skale, Justin J. Leisey

For many parts of the world, a voluntary divisional application (known as a continuation application in the U.S.) may be filed at any time during the pendency of any parent application.  The claims in the voluntary divisional application must be supported by the original specification and cannot introduce any new matter.  
Read more
IPRs and Other Post-Grant Porceedings Viewpoint Thumbnail

An Informative PTAB Decision on Fintiv Factors

January 8, 2021 | Blog | By Brad M Scheller, Justin J. Leisey

The U.S. Patent Trial and Appeal Board (“PTAB”) recently designated its decision in Snap, Inc. v. SRK Technology LLC (§ II.A), IPR2020-00820, Paper 15 (Oct. 21, 2020) (“Snap”) as being informative regarding the Fintiv factors analysis.
Read more
Patent Litigation Viewpoint Thumbnail

Recreating the Prior Art

October 7, 2020 | Blog | By Andrew D. Skale, Justin J. Leisey

In high-stakes litigation, parties go to great lengths to prove their case.  One such example is ongoing litigation between two giants in the paint and coatings world.  Sherwin-Williams Co. and PPG Industries, Inc. are involved in a patent infringement dispute over BPA-free can coatings.
Read more
Intellectual Property Viewpoints Thumbnail

An Informative PTAB Decision on Patent Eligibility under 35 U.S.C. § 101

January 30, 2020 | Blog | By Christina Sperry, Justin J. Leisey

The U.S. Patent Trial and Appeal Board (“PTAB”) recently designated its decision in Ex Parte HANNUN (Appeal 2018-003323) (“HANNUN”) as being informative regarding the application of the latest 2019 revised guidance on patent-eligible subject matter. 
Read more
Viewpoint Thumbnail

Ex parte WILHELM HEINE: PTAB Rejects Examiner’s Unreasonable Claim Construction

October 7, 2019 | Blog | By Andrew D. Skale, Justin J. Leisey

During patent prosecution, Examiners often liberally apply the broadest reasonable interpretation standard in rejecting claims.  When responding to these rejections, it is important to remember that there are limits to an Examiner’s broadest reasonable interpretation. 
Read more
Viewpoint Thumbnail

Federal Circuit Closes Another AIA Loophole

June 28, 2019 | Blog | By Michael Van Loy, Justin J. Leisey

The Federal Circuit recently ruled that state sovereign immunity does not apply in Inter Partes Review (IPR) proceedings, closing another America Invents Act (AIA) loophole.  The case, Regents of the University of Minnesota v. LSI Corporation and Avago Technologies U.S. Inc. (Fed. Circ., 2018-1559), included the review of six Patent Trial and Appeal Board (PTAB) IPRs where the Regents of the University of Minnesota (UMN) filed motions to dismiss based on state sovereign immunity. 
Read more