Inherent Disclosure

Standard

• A claim element is inherently anticipated if it is the 'natural result' or necessarily present when following the prior art reference's teachings
• The element must INEVITABLY arise from the prior art, not merely possibly or probably arise
• KEY CASE — SCHERING CORP. v. GENEVA PHARMACEUTICALS (Fed. Cir. 2003): loratadine (Claritin) was described in prior art
• Schering later obtained a patent on loratadine's active metabolite descarboethoxyloratadine (DCL)
• The Federal Circuit held that DCL was inherently anticipated because it was necessarily formed when loratadine was metabolized in the human body — even though the prior art never mentioned DCL
• The prior art author did not need to recognize or understand the inherent property
• KEY CASE — TITANIUM METALS CORP. v. BANNER (Fed. Cir. 1985): a prior art reference described a titanium alloy with certain composition ranges
• The patent claimed a narrower range with the property of improved corrosion resistance
• The Federal Circuit held the prior art inherently anticipated because the prior art compositions, when made, necessarily had the claimed property — even though the prior art never measured or identified corrosion resistance

Recognition not Required

• The person who practiced the prior art need not have recognized the inherent property
• If the property was necessarily there, anticipation applies
• 'NECESSARILY' vs. 'PROBABLY': the standard is strict
• If one who practices the prior art would sometimes but not always get the inherent result, there is no inherency
• The result must be certain.

Inherent Disclosure in Specification

• An inventor does not need to explicitly recite every element of the claimed invention in the specification if the element is necessarily present in what IS expressly described
• If practicing the described invention necessarily produces or requires the undisclosed element, the written description is inherently satisfied for that element

Key Difference from Express Disclosure

• Express disclosure directly states the claimed feature
• Inherent disclosure requires inference that the feature is necessarily present or produced

When it Arises

• Inherent disclosure in specifications is most commonly at issue in patent prosecution when an examiner rejects a claim as lacking written description
• The applicant argues the element was inherently disclosed because practicing the specification necessarily produces it

Limit — Newly Discovered Inherent Properties

• The inherent disclosure doctrine does not allow an inventor to add new matter by claiming a newly-discovered inherent property that was not recognized at the time of filing
• The property must be inherently disclosed, not just post-hoc discovered to be present.

Express Anticipation

• The prior art reference directly and explicitly describes every element of the claim
• No inference or testimony required
• The court reads the reference and finds every element stated
• Straightforward comparison of claim language vs. prior art language

Inherent Anticipation

• The prior art does not explicitly state an element, but the element was necessarily present when the reference's teachings were practiced
• Typically requires expert testimony or scientific evidence to establish that the undisclosed element inevitably results
• The party alleging anticipation bears the burden of showing necessity

Evidentiary Burden

• Proving inherency requires more than speculation
• The challenger must demonstrate through expert testimony, scientific publications, or experimental evidence that the result necessarily follows

Examples Contrasting Express and Inherent

• (1) Express: prior art says 'compound A has blue color' → claim element 'blue color' is expressly anticipated
• (2) Inherent: prior art says 'make compound A by heating X and Y together' → claim element 'compound A has blue color' is inherently anticipated if compound A necessarily has blue color when made by that process, even though color was never mentioned

Rebuttal of Inherency

• Patent owner rebuts inherent anticipation by: (a) showing the result is not necessarily produced (sometimes the prior art yields different results)
• (b) narrow claim construction showing the claimed element has a different meaning than the inherently-present property
• (c) challenging the quality of the challenger's inherency evidence.

Inherency Requires Certainty

• Inherency is not established by probability or conjecture
• Scientific or factual certainty is required
• Expert testimony alone, without supporting experimental or documentary evidence, may be insufficient

Expert Opinion not Enough

• Conclusory expert testimony that 'this compound is necessarily present' without a scientific basis for the conclusion is insufficient
• Experimental data, peer-reviewed literature, or established chemical/physical principles are needed

No 'Obvious to Try' Standard

• Inherent disclosure is NOT the same as obvious to try
• Even if a skilled person would expect a particular result, that expectation alone does not create inherency
• The result must actually, inevitably occur

Undiscovered Properties After Filing

• An inventor cannot add to a patent through inherency of newly-discovered properties
• If the property was truly unknown and unknowable at the time of filing, it was not inherently disclosed — but there is tension here with the recognition-not-required rule

Application to Ranges

• If a prior art range overlaps with or encompasses a claimed range, the claimed range may be inherently anticipated if the prior art necessarily produces species within the claimed range
• Overlapping numerical ranges in chemical/composition patents are a common inherency battleground.

Written Description and Inherency

• A claim is supported by adequate written description if the specification inherently discloses the claimed invention
• The key question is whether a person of ordinary skill would recognize that the specification necessarily describes the claimed feature
• AMGEN v. SANOFI (S.Ct. 2023): the Supreme Court reinforced the enablement requirement for broad genus claims — a patent must enable the full scope of what is claimed
• Inherent enablement of some species within a genus does not automatically enable the full genus

Best Mode

• An inventor is not required to disclose inherently-present properties of the claimed invention
• If the best mode of practicing the invention necessarily produces a certain result, that result is inherently within the best mode even if not expressly stated

Prosecution History Use

• When an applicant argues that a specification inherently discloses something to support a claim, this argument may later bind the claim's interpretation
• Courts will consider whether an element claimed as inherent was truly inherent at the time of filing or was a post-filing addition.