MPEP § 716.02(e) — Comparison With Closest Prior Art (Annotated Rules)

§716.02(e) Comparison With Closest Prior Art

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 716.02(e), including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Comparison With Closest Prior Art

This section addresses Comparison With Closest Prior Art. Primary authority: 35 U.S.C. 103 and 37 CFR 1.132. Contains: 4 requirements, 1 permission, and 6 other statements.

Key Rules

Topic

Establishing Prima Facie Case

10 rules
StatutoryRequiredAlways
[mpep-716-02-e-bd177baa62be9fde03e049b8]
Affidavit Must Compare Claimed Subject Matter to Closest Prior Art
Note:
An affidavit under 37 CFR 1.132 must compare the claimed invention with the closest prior art to effectively rebut a prima facie case of obviousness.

An affidavit or declaration under 37 CFR 1.132 must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979). “A comparison of the claimed invention with the disclosure of each cited reference to determine the number of claim limitations in common with each reference, bearing in mind the relative importance of particular limitations, will usually yield the closest single prior art reference.” In re Merchant, 575 F.2d 865, 868, 197 USPQ 785, 787 (CCPA 1978) (emphasis in original). Where the comparison is not identical with the reference disclosure, deviations therefrom should be explained, In re Finley, 174 F.2d 130, 81 USPQ 383 (CCPA 1949), and if not explained should be noted and evaluated, and if significant, explanation should be required. In re Armstrong, 280 F.2d 132, 126 USPQ 281 (CCPA 1960) (deviations from example were inconsequential).

Jump to MPEP Source · 37 CFR 1.132Establishing Prima Facie CaseRebutting Prima Facie CasePrima Facie Case of Obviousness
StatutoryInformativeAlways
[mpep-716-02-e-09269e3d9f1594e42e3a085c]
Requirement for Identifying Closest Single Prior Art Reference
Note:
The rule requires comparing the claimed invention with each cited reference to determine which one is closest, considering the importance of claim limitations.

An affidavit or declaration under 37 CFR 1.132 must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979). “A comparison of the claimed invention with the disclosure of each cited reference to determine the number of claim limitations in common with each reference, bearing in mind the relative importance of particular limitations, will usually yield the closest single prior art reference.” In re Merchant, 575 F.2d 865, 868, 197 USPQ 785, 787 (CCPA 1978) (emphasis in original). Where the comparison is not identical with the reference disclosure, deviations therefrom should be explained, In re Finley, 174 F.2d 130, 81 USPQ 383 (CCPA 1949), and if not explained should be noted and evaluated, and if significant, explanation should be required. In re Armstrong, 280 F.2d 132, 126 USPQ 281 (CCPA 1960) (deviations from example were inconsequential).

Jump to MPEP Source · 37 CFR 1.132Establishing Prima Facie CaseRebutting Prima Facie CasePrima Facie Case of Obviousness
StatutoryRequiredAlways
[mpep-716-02-e-40214a39ee7109e65ae9d9d9]
Comparison with Closest Prior Art Must Explain Deviations
Note:
The comparison must explain any deviations from the closest prior art, and if not explained, these should be noted and evaluated. Significant deviations require further explanation.

An affidavit or declaration under 37 CFR 1.132 must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979). “A comparison of the claimed invention with the disclosure of each cited reference to determine the number of claim limitations in common with each reference, bearing in mind the relative importance of particular limitations, will usually yield the closest single prior art reference.” In re Merchant, 575 F.2d 865, 868, 197 USPQ 785, 787 (CCPA 1978) (emphasis in original). Where the comparison is not identical with the reference disclosure, deviations therefrom should be explained, In re Finley, 174 F.2d 130, 81 USPQ 383 (CCPA 1949), and if not explained should be noted and evaluated, and if significant, explanation should be required. In re Armstrong, 280 F.2d 132, 126 USPQ 281 (CCPA 1960) (deviations from example were inconsequential).

Jump to MPEP Source · 37 CFR 1.132Establishing Prima Facie CaseRebutting Prima Facie CasePrima Facie Case of Obviousness
StatutoryInformativeAlways
[mpep-716-02-e-6407382d9d96c99a11384a1e]
Claimed Compound Compared to Closer Derivatives
Note:
Evidence showing unexpected results for the claimed compound compared to its 9-, 12-, and 14-chloro derivatives rebutted the prima facie case of obviousness.

Applicants may compare the claimed invention with prior art that is more closely related to the invention than the prior art relied upon by the examiner. In re Holladay, 584 F.2d 384, 199 USPQ 516 (CCPA 1978); Ex parte Humber, 217 USPQ 265 (Bd. App. 1961) (Claims to a 13-chloro substituted compound were rejected as obvious over nonchlorinated analogs of the claimed compound. Evidence showing unexpected results for the claimed compound as compared with the 9-, 12-, and 14- chloro derivatives of the compound rebutted the prima facie case of obviousness because the compounds compared against were closer to the claimed invention than the prior art relied upon.).

Jump to MPEP SourceEstablishing Prima Facie CasePrima Facie Case of ObviousnessObviousness
StatutoryInformativeAlways
[mpep-716-02-e-38321c9bfa94a37470313cfe]
Testing Less Than All Closest Prior Art Compounds Is Insufficient To Rebut Prima Facie Obviousness
Note:
The court found evidence insufficient to rebut prima facie case of obviousness when the applicant tested only one compound from the closest prior art, failing to show relative effectiveness over all compounds.

Showing unexpected results over one of two equally close prior art references will not rebut prima facie obviousness unless the teachings of the prior art references are sufficiently similar to each other that the testing of one showing unexpected results would provide the same information as to the other. In re Johnson, 747 F.2d 1456, 1461, 223 USPQ 1260, 1264 (Fed. Cir. 1984) (Claimed compounds differed from the prior art either by the presence of a trifluoromethyl group instead of a chloride radical, or by the presence of an unsaturated ester group instead of a saturated ester group. Although applicant compared the claimed invention with the prior art compound containing a chloride radical, the court found this evidence insufficient to rebut the prima facie case of obviousness because the evidence did not show relative effectiveness over all compounds of the closest prior art. An applicant does not have to test all the compounds taught by each reference, “[h]owever, where an applicant tests less than all cited compounds, the test must be sufficient to permit a conclusion respecting the relative effectiveness of applicant’s claimed compounds and the compounds of the closest prior art. ” Id. (quoting In re Payne, 606 F.2d 303, 316, 203 USPQ 245, 256 (CCPA 1979)) (emphasis in original).).

Jump to MPEP SourceEstablishing Prima Facie CaseRebutting Prima Facie CasePrima Facie Case of Obviousness
StatutoryRequiredAlways
[mpep-716-02-e-8562c20237dc0526c535c243]
Testing Less Than All Cited Compounds Must Be Sufficient
Note:
An applicant must test enough compounds to compare their effectiveness with the closest prior art, even if not all cited compounds are tested.

Showing unexpected results over one of two equally close prior art references will not rebut prima facie obviousness unless the teachings of the prior art references are sufficiently similar to each other that the testing of one showing unexpected results would provide the same information as to the other. In re Johnson, 747 F.2d 1456, 1461, 223 USPQ 1260, 1264 (Fed. Cir. 1984) (Claimed compounds differed from the prior art either by the presence of a trifluoromethyl group instead of a chloride radical, or by the presence of an unsaturated ester group instead of a saturated ester group. Although applicant compared the claimed invention with the prior art compound containing a chloride radical, the court found this evidence insufficient to rebut the prima facie case of obviousness because the evidence did not show relative effectiveness over all compounds of the closest prior art. An applicant does not have to test all the compounds taught by each reference, “[h]owever, where an applicant tests less than all cited compounds, the test must be sufficient to permit a conclusion respecting the relative effectiveness of applicant’s claimed compounds and the compounds of the closest prior art. ” Id. (quoting In re Payne, 606 F.2d 303, 316, 203 USPQ 245, 256 (CCPA 1979)) (emphasis in original).).

Jump to MPEP SourceEstablishing Prima Facie CaseRebutting Prima Facie CasePrima Facie Case of Obviousness
StatutoryInformativeAlways
[mpep-716-02-e-b1f64ebc02d01c044778e228]
Testing of Less Than All Cited Compounds Must Provide Relative Effectiveness
Note:
An applicant must test enough compounds to show the relative effectiveness of their claimed invention compared to the closest prior art, especially when testing less than all cited compounds.

Showing unexpected results over one of two equally close prior art references will not rebut prima facie obviousness unless the teachings of the prior art references are sufficiently similar to each other that the testing of one showing unexpected results would provide the same information as to the other. In re Johnson, 747 F.2d 1456, 1461, 223 USPQ 1260, 1264 (Fed. Cir. 1984) (Claimed compounds differed from the prior art either by the presence of a trifluoromethyl group instead of a chloride radical, or by the presence of an unsaturated ester group instead of a saturated ester group. Although applicant compared the claimed invention with the prior art compound containing a chloride radical, the court found this evidence insufficient to rebut the prima facie case of obviousness because the evidence did not show relative effectiveness over all compounds of the closest prior art. An applicant does not have to test all the compounds taught by each reference, “[h]owever, where an applicant tests less than all cited compounds, the test must be sufficient to permit a conclusion respecting the relative effectiveness of applicant’s claimed compounds and the compounds of the closest prior art. ” Id. (quoting In re Payne, 606 F.2d 303, 316, 203 USPQ 245, 256 (CCPA 1979)) (emphasis in original).).

Jump to MPEP SourceEstablishing Prima Facie CaseRebutting Prima Facie CasePrima Facie Case of Obviousness
StatutoryRequiredAlways
[mpep-716-02-e-e510991786b7cd51a793fca1]
Evidence of Unexpected Results Must Compare Invention to Closest Prior Art
Note:
The rule states that evidence of unexpected results must be compared with the closest prior art, not non-existent subject matter.

Although evidence of unexpected results must compare the claimed invention with the closest prior art, applicant is not required to compare the claimed invention with subject matter that does not exist in the prior art. In re Geiger, 815 F.2d 686, 689, 2 USPQ2d 1276, 1279 (Fed. Cir. 1987) (Newman, J., concurring) (Evidence rebutted prima facie case by comparing claimed invention with the most relevant prior art. Note that the majority held the Office failed to establish a prima facie case of obviousness.); In re Chapman, 357 F.2d 418, 148 USPQ 711 (CCPA 1966) (Requiring applicant to compare claimed invention with polymer suggested by the combination of references relied upon in the rejection of the claimed invention under 35 U.S.C. 103 “would be requiring comparison of the results of the invention with the results of the invention.” 357 F.2d at 422, 148 USPQ at 714.).

Jump to MPEP SourceEstablishing Prima Facie CasePrima Facie Case of ObviousnessObviousness
StatutoryInformativeAlways
[mpep-716-02-e-76dfb1ce436d573a64412857]
Office Failed to Establish Prima Facie Case of Obviousness
Note:
The Office was unable to prove that the claimed invention was obvious based on prior art.

Although evidence of unexpected results must compare the claimed invention with the closest prior art, applicant is not required to compare the claimed invention with subject matter that does not exist in the prior art. In re Geiger, 815 F.2d 686, 689, 2 USPQ2d 1276, 1279 (Fed. Cir. 1987) (Newman, J., concurring) (Evidence rebutted prima facie case by comparing claimed invention with the most relevant prior art. Note that the majority held the Office failed to establish a prima facie case of obviousness.); In re Chapman, 357 F.2d 418, 148 USPQ 711 (CCPA 1966) (Requiring applicant to compare claimed invention with polymer suggested by the combination of references relied upon in the rejection of the claimed invention under 35 U.S.C. 103 “would be requiring comparison of the results of the invention with the results of the invention.” 357 F.2d at 422, 148 USPQ at 714.).

Jump to MPEP SourceEstablishing Prima Facie CasePrima Facie Case of ObviousnessObviousness
StatutoryInformativeAlways
[mpep-716-02-e-d40f78f94aacf219fdfa306a]
Claimed Invention Must Be Compared to Closest Prior Art
Note:
The claimed invention must be compared with the closest prior art, not with non-existent prior art.

Although evidence of unexpected results must compare the claimed invention with the closest prior art, applicant is not required to compare the claimed invention with subject matter that does not exist in the prior art. In re Geiger, 815 F.2d 686, 689, 2 USPQ2d 1276, 1279 (Fed. Cir. 1987) (Newman, J., concurring) (Evidence rebutted prima facie case by comparing claimed invention with the most relevant prior art. Note that the majority held the Office failed to establish a prima facie case of obviousness.); In re Chapman, 357 F.2d 418, 148 USPQ 711 (CCPA 1966) (Requiring applicant to compare claimed invention with polymer suggested by the combination of references relied upon in the rejection of the claimed invention under 35 U.S.C. 103 “would be requiring comparison of the results of the invention with the results of the invention.” 357 F.2d at 422, 148 USPQ at 714.).

Jump to MPEP SourceEstablishing Prima Facie CasePrima Facie Case of ObviousnessObviousness
Topic

35 U.S.C. 103 – Obviousness

2 rules
StatutoryPermittedAlways
[mpep-716-02-e-53b2a1c0dbe7ba15ef777391]
Claimed Invention Must Be Compared to More Closely Related Art
Note:
Applicants must compare the claimed invention with prior art that is more closely related than what the examiner relied upon.

Applicants may compare the claimed invention with prior art that is more closely related to the invention than the prior art relied upon by the examiner. In re Holladay, 584 F.2d 384, 199 USPQ 516 (CCPA 1978); Ex parte Humber, 217 USPQ 265 (Bd. App. 1961) (Claims to a 13-chloro substituted compound were rejected as obvious over nonchlorinated analogs of the claimed compound. Evidence showing unexpected results for the claimed compound as compared with the 9-, 12-, and 14- chloro derivatives of the compound rebutted the prima facie case of obviousness because the compounds compared against were closer to the claimed invention than the prior art relied upon.).

Jump to MPEP SourceObviousnessEstablishing Prima Facie CasePrima Facie Case of Obviousness
StatutoryInformativeAlways
[mpep-716-02-e-3e60d06cdd6dcf3b568eeb19]
Requirement for Comparing Invention with Closest Prior Art
Note:
The rule requires that evidence of unexpected results must compare the claimed invention with the closest prior art, not with a combination of references suggested in an obviousness rejection.

Although evidence of unexpected results must compare the claimed invention with the closest prior art, applicant is not required to compare the claimed invention with subject matter that does not exist in the prior art. In re Geiger, 815 F.2d 686, 689, 2 USPQ2d 1276, 1279 (Fed. Cir. 1987) (Newman, J., concurring) (Evidence rebutted prima facie case by comparing claimed invention with the most relevant prior art. Note that the majority held the Office failed to establish a prima facie case of obviousness.); In re Chapman, 357 F.2d 418, 148 USPQ 711 (CCPA 1966) (Requiring applicant to compare claimed invention with polymer suggested by the combination of references relied upon in the rejection of the claimed invention under 35 U.S.C. 103 “would be requiring comparison of the results of the invention with the results of the invention.” 357 F.2d at 422, 148 USPQ at 714.).

Jump to MPEP SourceObviousnessEstablishing Prima Facie CasePrima Facie Case of Obviousness
Topic

Rebutting Prima Facie Case

1 rules
StatutoryInformativeAlways
[mpep-716-02-e-400f03d4ce3d50728b8bd084]
Showing Unexpected Results Over Close Prior Art
Note:
A showing of unexpected results over one close prior art reference will not rebut a prima facie case of obviousness unless the tests on both references are sufficiently similar.

Showing unexpected results over one of two equally close prior art references will not rebut prima facie obviousness unless the teachings of the prior art references are sufficiently similar to each other that the testing of one showing unexpected results would provide the same information as to the other. In re Johnson, 747 F.2d 1456, 1461, 223 USPQ 1260, 1264 (Fed. Cir. 1984) (Claimed compounds differed from the prior art either by the presence of a trifluoromethyl group instead of a chloride radical, or by the presence of an unsaturated ester group instead of a saturated ester group. Although applicant compared the claimed invention with the prior art compound containing a chloride radical, the court found this evidence insufficient to rebut the prima facie case of obviousness because the evidence did not show relative effectiveness over all compounds of the closest prior art. An applicant does not have to test all the compounds taught by each reference, “[h]owever, where an applicant tests less than all cited compounds, the test must be sufficient to permit a conclusion respecting the relative effectiveness of applicant’s claimed compounds and the compounds of the closest prior art. ” Id. (quoting In re Payne, 606 F.2d 303, 316, 203 USPQ 245, 256 (CCPA 1979)) (emphasis in original).).

Jump to MPEP SourceRebutting Prima Facie CasePrima Facie Case of ObviousnessObviousness

Citations

Primary topicCitation
35 U.S.C. 103 – Obviousness
Establishing Prima Facie Case
35 U.S.C. § 103
Establishing Prima Facie Case37 CFR § 1.132
Establishing Prima Facie CaseIn re Armstrong, 280 F.2d 132, 126 USPQ 281 (CCPA 1960)
Establishing Prima Facie CaseIn re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979)
35 U.S.C. 103 – Obviousness
Establishing Prima Facie Case
In re Chapman, 357 F.2d 418, 148 USPQ 711 (CCPA 1966)
Establishing Prima Facie CaseIn re Finley, 174 F.2d 130, 81 USPQ 383 (CCPA 1949)
35 U.S.C. 103 – Obviousness
Establishing Prima Facie Case
In re Geiger, 815 F.2d 686, 689, 2 USPQ2d 1276, 1279 (Fed. Cir. 1987)
35 U.S.C. 103 – Obviousness
Establishing Prima Facie Case
In re Holladay, 584 F.2d 384, 199 USPQ 516 (CCPA 1978)
Establishing Prima Facie Case
Rebutting Prima Facie Case
In re Johnson, 747 F.2d 1456, 1461, 223 USPQ 1260, 1264 (Fed. Cir. 1984)
Establishing Prima Facie CaseIn re Merchant, 575 F.2d 865, 868, 197 USPQ 785, 787 (CCPA 1978)
Establishing Prima Facie Case
Rebutting Prima Facie Case
In re Payne, 606 F.2d 303, 316, 203 USPQ 245, 256 (CCPA 1979)

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31