Obviousness-Type Double Patenting

Obviousness-type double patenting (ODP) is a judicially created doctrine that prevents a patentee from using continuation applications to extend monopoly protection beyond the expiration of a first patent by claiming obvious variants: THE PROBLEM ODP SOLVES: patent term is measured from the filing date (post-AIA) or 20 years from earliest priority date; an applicant could file an application (App 1), get a patent with claims A; then file a continuation (App 2) with claims that are minor variations of A; get a second patent with a later expiration date; continue filing continuations with each one extending the effective monopoly by small variations; ODP prevents this by invalidating later claims that are obvious variants of the earlier claims; STATUTORY DOUBLE PATENTING (35 U.S.C. § 101): different from ODP; involves IDENTICAL claims; cannot be overcome by a terminal disclaimer — it is an absolute bar; JUDICIALLY CREATED ODP: not in the statute — created by federal courts; applies to claims that are OBVIOUS VARIANTS of each other (not identical); CAN be overcome by a terminal disclaimer; THE ANALYSIS: ODP requires a two-way obvious analysis in some cases; typically: are the claims of the later patent obvious in view of the claims (not specification) of the earlier patent? KEY FEATURE: the ODP analysis looks at CLAIMS to CLAIMS — not at claims vs. prior art; the earlier patent's claims are the reference; COMMONLY OWNED APPLICATIONS: ODP applies between: applications by the same inventor; applications by different inventors if commonly assigned (35 U.S.C. § 103(c) provides safe harbor in limited circumstances); continuations, divisionals, and continuation-in-part applications in the same family.

A terminal disclaimer (TD) is the primary mechanism for overcoming an ODP rejection: WHAT A TERMINAL DISCLAIMER DOES: disclaims the portion of the later patent's term that extends beyond the earlier patent's expiration date; ties the two patents' terms together — they both expire on the same date (the earlier expiration); EFFECT ON PATENT TERM: if Patent A expires on December 1, 2030, and Patent B (subject to ODP rejection) would normally expire on June 1, 2033, a TD filed in Patent B makes Patent B also expire on December 1, 2030; Patent B loses the 2.5 years of additional term; WHAT A TD ALSO REQUIRES: the later patent will only be enforceable as long as both patents are owned by the same entity; if the patents are separated (sold, licensed to different parties), enforcement of the TD-encumbered patent can be affected; PRACTICAL CONSIDERATIONS: most patent families include TDs in continuation applications; common in pharmaceutical, biotech, and software patent families where many continuation applications are filed; once a TD is filed, it cannot be retracted; TD STRATEGY: file TDs routinely for continuation applications in a family; don't fight ODP rejections on the merits unless there is a specific reason to maintain the extra term (e.g., patent term extension for FDA approval); PATENT TERM ADJUSTMENT (PTA) AND TERMINAL DISCLAIMERS — CELLECT IMPACT: In re Cellect (Fed. Cir. 2023): ODP applies even when the later patent's extended term is due to PTA (not the applicant's own filing delays); if a patent has PTA and would expire later than a parent due to PTA, an ODP rejection can be issued; filing a TD eliminates the PTA-extended term; applicants must now carefully consider whether to fight ODP or accept TDs in view of PTA; PRACTICE NOTE POST-CELLECT: for patents with significant PTA, carefully consider whether the PTA extension is more valuable than avoiding the TD encumbrance.

Understanding when ODP is valid and how to respond helps manage prosecution effectively: VALID ODP REJECTION — REQUIREMENTS: examiner must: (a) identify the reference patent (usually an earlier issued patent in the family); (b) identify specific claim(s) in the reference patent; (c) conduct an obviousness-type analysis comparing the reference claims to the rejected claims; (d) explain why the rejected claims are obvious in view of the reference claims; CHALLENGING AN ODP REJECTION — WHEN TO FIGHT: if the claims are NOT obvious over the reference claims (the variation is patentable); if the reference patent's claims have been invalidated or cancelled (obviousness over cancelled claims may not support ODP); if there are terminal disclaimers already filed that limit the reference patent term to the same date; rarely worth fighting unless the TD's term cost is significant (e.g., PTA); RESPONDING WITH A TERMINAL DISCLAIMER: file TD using USPTO Form PTO/SB/20; agrees to both: (a) limiting the later patent's expiration to the earlier patent's expiration; (b) maintaining common ownership with the reference patent during any period of enforcement; TD is immediate — once filed and accepted, the later patent's term is tied to the reference patent; NO MERIT FIGHT NEEDED: once TD filed, ODP rejection is withdrawn; TD does not affect validity of the claims on the merits (does not create estoppel or admission of obviousness); DOUBLE PATENTING BETWEEN DIVISIONALS: restriction requirement leads to divisional applications; inventions divided by restriction requirement are NOT subject to ODP between the resulting patents under § 121 safe harbor; however, the § 121 safe harbor only applies to claims that were the subject of the restriction requirement; broadly claiming across divided groups is still subject to ODP.

ODP is particularly important in pharmaceutical and biotech patent portfolios because of patent term extension and continuation strategies: PHARMA PATENT FAMILIES: typical pharma patent family: compound patent (first filed, basic composition claims); method of treatment patent (continuation or divisional); dosage form patent; formulation patent; metabolite patent; each continuation may receive an ODP rejection over the compound patent; all TDs tie expiration to the compound patent; FDA PATENT TERM EXTENSION (35 U.S.C. § 156): grants up to 5 years of additional patent term to compensate for FDA regulatory review; applies to the product patent (usually the compound patent); ODP AND § 156 EXTENSION: a TD filed before PTE may limit or eliminate the benefit of the PTE; the TD ties the later patent to the reference patent's original expiration — before PTE is applied; this can result in the TD-encumbered patent expiring BEFORE the reference patent (after PTE); complex interaction requires careful analysis before filing TDs in families where § 156 PTE is expected; AIA FIRST-INVENTOR-TO-FILE: post-AIA, ODP analysis changed slightly; pre-AIA: ODP focused on whether earlier patent was filed first; post-AIA: no requirement that reference patent was filed earlier — the effective filing date analysis differs; BIOTECH GENUS PATENTS: biotech companies often file genus patents (covering a class of compounds) and species patents (specific compounds within the genus); if the species claims are obvious from the genus claims, ODP rejection issues; filing TDs ties all species patents to the genus patent's expiration; STRATEGY: consider ODP implications when building a portfolio strategy; continuation applications with TDs still provide value: multiple enforcement opportunities; different claim sets covering design-arounds; each patent can be asserted independently even with shared expiration.

In re Cellect (Fed. Cir. 2023) significantly changed how ODP interacts with patent term adjustment (PTA): BACKGROUND — PATENT TERM ADJUSTMENT: PTA compensates for USPTO delays in prosecution under 35 U.S.C. § 154(b); if the USPTO takes more than 14 months to issue a first office action, more than 4 months to respond, or the application is pending more than 3 years, the applicant gets PTA; PTA extends the patent's 20-year term day-for-day for these delays; PRE-CELLECT UNDERSTANDING: many practitioners assumed ODP would not apply to PTA-extended patents because PTA is a statutory right, not the patentee's fault; patentees often filed continuation applications and accepted that the continuation would have a later normal expiration, expecting ODP would not be raised based on PTA; THE CELLECT HOLDING: Federal Circuit: ODP applies to PTA-extended term; if a continuation patent would expire later than the parent BECAUSE OF PTA (not inherent term), ODP can still be asserted against it; a terminal disclaimer is the cure; courts can invalidate the later patent claims (or reduce them to the parent's expiration) if no TD was filed; PRACTICAL IMPACT POST-CELLECT: applicants receiving ODP rejections based on PTA extension should generally file TDs rather than fighting; BUT carefully calculate whether the PTA extension is more valuable than the TD overhead; if the parent had no PTA and the continuation has significant PTA, the TD costs real patent term; PATENT OFFICE POSITION: USPTO updated examination guidance to reflect Cellect; examiners now regularly issue ODP rejections when continuation patent has PTA beyond parent expiration; CELLECT IN LITIGATION: defendants increasingly challenge continuation patents on ODP/Cellect grounds in patent litigation, particularly where no TD was filed and the continuation's term extends beyond the parent's; effective invalidity tool against late-filed continuations in pharmaceutical and software patent families.