Ex parte Baurin Makes Anti-Harassment a Standalone Obviousness-Type Double Patenting Rationale—For Now

On August 6, 2026, the USPTO designated Ex parte Baurin, Appeal 2024-002920, as a precedential Appeals Review Panel decision. The case addresses a deceptively important question in obviousness-type double patenting: can the doctrine apply even when the later patent would not extend the overall expiration date of the patent family?

The Appeals Review Panel answered yes under current Federal Circuit precedent. It reinstated the examiner’s obviousness-type double patenting rejection and concluded that the risk of separate ownership and repeated harassment by owners of obvious variants can independently support the doctrine even when there is no patent-term extension. At the same time, the panel openly questioned whether that standalone anti-harassment rationale remains sound policy and suggested that the Federal Circuit may ultimately need to reconsider it.

The USPTO’s precedential decision in Ex parte Baurin therefore matters both for current prosecution practice and for the future direction of double-patenting law.

What is obviousness-type double patenting?

Obviousness-type double patenting, often abbreviated OTDP or ODP, is a judicially created doctrine intended to prevent an inventor or patent owner from obtaining unjustified additional patent rights on claims that are not patentably distinct from claims in another patent.

Historically, two policy concerns appear repeatedly in the cases. One is improper patent-term extension: a patentee should not be able to extend exclusivity by obtaining a second patent on an obvious variant of the same invention. The other is the risk of separate ownership: if overlapping patents end up in different hands, an accused party could face repeated suits or licensing pressure from multiple owners over essentially the same invention.

A terminal disclaimer is often used to overcome an OTDP rejection. It can tie the term of one patent to another and require common ownership or enforceability conditions. But a terminal disclaimer can have significant business consequences, especially in a portfolio that might later be sold, licensed, financed, or divided among affiliates.

The unusual posture in Baurin

The application at issue was U.S. Application No. 17/135,529. According to the decision, the application traced priority through continuation applications to a nonprovisional application filed March 28, 2012. Any patent issuing from the application would therefore have a natural term ending March 28, 2032 absent other adjustments. Existing terminal disclaimers over other patents also meant that the application could not produce a patent extending beyond that date.

That created the central issue: if no extra patent term was available, what policy justified an OTDP rejection?

The earlier Board panel had reversed the examiner’s rejection. The Appeals Review Panel—consisting of the USPTO Director and senior PTAB judges—reconsidered the issue and reinstated it.

The precedential holding: anti-harassment can stand on its own

The Appeals Review Panel concluded that Federal Circuit precedent recognizes separate ownership and anti-harassment as a legitimate, independent rationale for obviousness-type double patenting. In other words, current law does not require the USPTO to prove that a second patent would actually extend the expiration date before applying OTDP.

That is the immediate rule practitioners need to work with. Applicants cannot assume that matching expiration dates eliminate double-patenting risk.

The USPTO’s own summary emphasizes the point: Baurin is now precedential for the proposition that separate ownership and anti-harassment can independently support OTDP. The decision is listed among the agency’s precedential PTAB decisions.

But the panel also questioned the rule it applied

The most interesting part of Baurin may be the panel’s skepticism about the anti-harassment rationale itself. The panel suggested that applying OTDP solely to avoid hypothetical future harassment may impose costs on innovation and portfolio management even when the public receives no additional patent-term burden.

That tension makes the decision unusual. The USPTO treated the Federal Circuit’s precedent as controlling, but effectively invited further judicial consideration of whether the doctrine should continue to operate the same way.

Patent applicants should not read that discussion as permission to ignore OTDP today. Until the law changes, the precedential decision governs USPTO practice.

Why terminal disclaimers deserve business-level attention

A terminal disclaimer is not merely prosecution paperwork. It can affect the future value and flexibility of a patent family.

Before filing one, applicants should consider questions such as:

• Will the patents need to remain commonly owned?
• Could different parts of the portfolio be licensed or sold separately?
• Are there financing, acquisition, or joint-venture plans that depend on separating assets?
• Does the rejection actually satisfy the legal requirements for OTDP?
• Could claim amendments or argument avoid the rejection without a disclaimer?

For startups and technology companies, those questions can matter years after prosecution ends. Tucker Law’s patent application practice focuses on claim and portfolio strategy as well as the immediate goal of obtaining allowance.

A better prosecution workflow after Baurin

Map the patent family early. Continuations, divisionals, continuations-in-part, terminal disclaimers, patent-term adjustment, and patent-term extension can interact in ways that are difficult to reconstruct late in prosecution.

Do not assume same-day expiration solves OTDP. Baurin specifically rejects that shortcut under current precedent.

Evaluate the reference claims carefully. An OTDP rejection still requires a patentability comparison. The existence of related patents does not automatically make every later claim an obvious variant.

Consider portfolio ownership before filing a terminal disclaimer. A disclaimer can create constraints that affect later transactions.

Preserve arguments for appeal when appropriate. Because the panel itself questioned the continued force of a standalone anti-harassment rationale, future cases may continue to test the doctrine.

Why this precedential decision matters beyond one application

Precedential PTAB decisions establish binding authority on important issues of Board policy and practice. Baurin therefore has broader significance than a routine ex parte appeal. Examiners and applicants now have a clear USPTO position on the anti-harassment rationale unless and until controlling law changes.

Tucker Law handles patent prosecution and patent disputes, including matters that reach the Patent Trial and Appeal Board. For businesses with multiple related applications, double-patenting strategy should be coordinated with the broader goals for the portfolio rather than addressed one Office Action at a time.

This article provides general legal information and is not legal advice. Double-patenting analysis is highly dependent on the claims, priority chain, ownership, patent term, and procedural record.