Reasonable Expectation of Success Is Required

[Editor Note: This MPEP section is applicable regardless of whether an

application is examined under the AIA or under pre-AIA law. For applications subject

to the first inventor to file (FITF) provisions of the AIA, the relevant time is

"before the effective filing date of the claimed invention". For applications subject

to

pre-AIA 35

U.S.C. 102

, the relevant time is "at the time of the

invention". See

MPEP § 2150

et seq. Many of the

court decisions discussed in this section involved applications or patents subject to

pre-AIA 35

U.S.C. 102

. These court decisions may be applicable to

applications and patents subject to

AIA 35 U.S.C. 102

but the

relevant time is before the effective filing date of the claimed invention and not at

the time of the invention.]

I.

OBVIOUSNESS REQUIRES A REASONABLE EXPECTATION OF SUCCESS

Where there is a reason to modify or combine the prior art to

achieve the claimed invention, the claims may be rejected as

prima

facie

obvious provided there is also a reasonable expectation of

success. The reasonable expectation of success requirement refers to “the likelihood

of success” in combining or modifying prior art disclosures to meet the limitations

of the claimed invention. See

Elekta Ltd. v. ZAP Surgical Sys.,

Inc.,

81 F.4th 1368, 1375, 2023 USPQ2d 1100 (Fed. Cir. 2023) and

Intelligent Bio-Sys., Inc. v. Illumina Cambridge Ltd.,

821 F.3d

1359, 1367, 119 USPQ2d 1171, 1176 (Fed. Cir. 2016). See

MPEP § 2143

for

guidance on rationales for modifying or combining the prior art. In

In re

Merck & Co., Inc.,

800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986), the

Board affirmed a rejection of claims directed to a method of treating depression with

amitriptyline (or nontoxic salts thereof) as

prima facie

obvious.

The prior art disclosed that amitriptyline is a compound known to possess

psychotropic properties and that imipramine is a structurally similar psychotropic

compound known to possess antidepressive properties

091, 231 USPQ 375 (Fed. Cir. 1986), the

Board affirmed a rejection of claims directed to a method of treating depression with

amitriptyline (or nontoxic salts thereof) as

prima facie

obvious.

The prior art disclosed that amitriptyline is a compound known to possess

psychotropic properties and that imipramine is a structurally similar psychotropic

compound known to possess antidepressive properties. Additional prior art, suggested

that these compounds would have been expected to have similar activity because the

structural difference between them involved a known bioisosteric replacement, and

because a research paper comparing the pharmacological properties of these two

compounds suggested clinical testing of amitriptyline as an antidepressant. The court

affirmed the Board’s determination, finding that the teachings of the prior art

provided a sufficient basis for a reasonable expectation of success.) In

Ex

parte Blanc,

13 USPQ2d 1383 (Bd. Pat. App. & Inter. 1989) (the

claims were directed to a process of sterilizing a polyolefinic composition with

high-energy radiation in the presence of a phenolic polyester antioxidant to inhibit

discoloration or degradation of the polyolefin. Appellant argued that it is

unpredictable whether a particular antioxidant will solve the problem of

discoloration or degradation. However, the Board found that because the prior art

taught that appellant’s preferred antioxidant is very efficient and provides better

results compared with other prior art antioxidants, there would have been a

reasonable expectation of success.).

As discussed above, reasonable expectation of success

can be implicitly shown via the prior art teachings or as part of the obviousness

analysis. See

Elekta Ltd. v. ZAP Surgical Sys., Inc.,

81 F.4th

1368, 1376-77, 2023 USPQ2d 1100 (Fed. Cir. 2023) (“[W]e can reasonably discern that

the Board considered and implicitly addressed reasonable expectation of success based

on the arguments and evidence presented to the Board on motivation to combine.”)

cess

can be implicitly shown via the prior art teachings or as part of the obviousness

analysis. See

Elekta Ltd. v. ZAP Surgical Sys., Inc.,

81 F.4th

1368, 1376-77, 2023 USPQ2d 1100 (Fed. Cir. 2023) (“[W]e can reasonably discern that

the Board considered and implicitly addressed reasonable expectation of success based

on the arguments and evidence presented to the Board on motivation to combine.”). In

this decision, the court found the Board’s explanation on why the patent owner's

arguments and evidence presented on motivation to combine were not persuasive

implicitly addressed reasonable expectation of success and was supported by

substantial evidence. On the other hand, depending on the situation (e.g., the

technology, the prior art teachings and the obviousness analysis), reliance on an

implicit showing of reasonable expectation of success may not be sufficient to

establish a

prima facie

showing of obviousness.

Eli Lilly

& Co. v. Teva Pharms. Int’l GmbH,

8 F.4th 1331, 1344, 2021 USPQ2d

862 (Fed. Cir. 2021) (A finding that a patent challenger in an

inter

partes

review had demonstrated a motivation to combine references does

not necessarily imply that the challenger had also met its burden of showing a

reasonable expectation of success in achieving a claimed method of treatment.). In

this case, the court found that the challenged method of treating claims “contain

limitations related to their intended purpose for treating vasomotor symptoms [as

stated in the preamble], and thus those limitations are undoubtedly relevant to the

reasonable expectation of success.”

Id.

at 1345. In other words,

the court found that the preamble was limiting and applicable to reasonable

expectation of success. However, the limitations in the preamble were not addressed

in the motivation to combine analysis. Any obviousness rejection should include,

either explicitly or implicitly, an indication of a reasonable expectation of

success.

Conclusive proof of efficacy is not required to show

a reasonable expectation of success

that the preamble was limiting and applicable to reasonable

expectation of success. However, the limitations in the preamble were not addressed

in the motivation to combine analysis. Any obviousness rejection should include,

either explicitly or implicitly, an indication of a reasonable expectation of

success.

Conclusive proof of efficacy is not required to show

a reasonable expectation of success.

OSI Pharm., LLC v. Apotex

Inc.,

939 F.3d 1375, 1385, 2019 USPQ2d 379681 (Fed. Cir. 2019) (“To be

clear, we do not hold today that efficacy data is always required for a reasonable

expectation of success. Nor are we requiring ‘absolute predictability of success.’”);

Acorda Therapeutics, Inc. v. Roxane Lab., Inc.,

903 F.3d 1310,

1333, 128 USPQ2d 1001, 1018 (Fed. Cir. 2018) (“This court has long rejected a

requirement of ‘[c]onclusive proof of efficacy’ for obviousness.” (citing to

Hoffmann-La Roche Inc. v. Apotex Inc.,

748 F.3d 1326, 1331

(Fed. Cir. 2014);

PharmaStem Therapeutics, Inc. v. ViaCell, Inc.,

491 F.3d 1342, 1364 (Fed. Cir. 2007);

Pfizer, Inc. v. Apotex,

Inc.,

480 F.3d 1348, 1364, 1367–68 (Fed. Cir. 2007) (reasoning that “the

expectation of success need only be reasonable, not absolute”)).

II.

AT LEAST SOME DEGREE OF PREDICTABILITY IS REQUIRED; APPLICANTS MAY PRESENT

EVIDENCE SHOWING THERE WAS NO REASONABLE EXPECTATION OF SUCCESS

Obviousness does not require absolute predictability, but at least

some degree of predictability is required. Evidence showing there was no reasonable

expectation of success may support a conclusion of nonobviousness.

In re

Rinehart,

531 F.2d 1048, 189 USPQ 143 (CCPA 1976) (Claims directed to a

method for the commercial scale production of polyesters in the presence of a solvent

at superatmospheric pressure were rejected as obvious over a reference which taught

the claimed method at atmospheric pressure in view of a reference which taught the

claimed process except for the presence of a solvent

nonobviousness.

In re

Rinehart,

531 F.2d 1048, 189 USPQ 143 (CCPA 1976) (Claims directed to a

method for the commercial scale production of polyesters in the presence of a solvent

at superatmospheric pressure were rejected as obvious over a reference which taught

the claimed method at atmospheric pressure in view of a reference which taught the

claimed process except for the presence of a solvent. The court reversed, finding

there was no reasonable expectation that a process combining the prior art steps

could be successfully scaled up in view of unchallenged evidence showing that the

prior art processes individually could not be commercially scaled up successfully.).

See also

OSI Pharm., LLC v. Apotex Inc.,

939 F.3d 1375, 1385, 2019

USPQ2d 379681 (Fed. Cir. 2019) (“These references provide no more than hope—and hope

that a potentially promising drug will treat a particular cancer is not enough to

create a reasonable expectation of success in a highly unpredictable art such as

this. Indeed, given a 99.5% failure rate and no efficacy data or any other reliable

indicator of success, the only reasonable expectation at the time of the invention

was failure, not success.”);

Amgen, Inc. v. Chugai Pharm. Co.,

927

F.2d 1200, 1207-08, 18 USPQ2d 1016, 1022-23 (Fed. Cir. 1991),

cert.

denied,

502 U.S. 856 (1991) (In the context of a biotechnology case,

testimony supported the conclusion that the references did not show that there was a

reasonable expectation of success.);

In re O’Farrell,

853 F.2d

894, 903, 7 USPQ2d 1673, 1681 (Fed. Cir. 1988) (The court held the claimed method

would have been obvious over the prior art relied upon because one reference

contained a detailed enabling methodology, a suggestion to modify the prior art to

produce the claimed invention, and evidence suggesting the modification would be

successful.).

III

sonable expectation of success.);

In re O’Farrell,

853 F.2d

894, 903, 7 USPQ2d 1673, 1681 (Fed. Cir. 1988) (The court held the claimed method

would have been obvious over the prior art relied upon because one reference

contained a detailed enabling methodology, a suggestion to modify the prior art to

produce the claimed invention, and evidence suggesting the modification would be

successful.).

III.

PREDICTABILITY IS DETERMINED AT THE RELEVANT TIME

Whether an art is predictable or whether the proposed modification

or combination of the prior art has a reasonable expectation of success is determined

at the time the invention was made for pre-AIA obviousness analysis.

Ex

parte Erlich,

3 USPQ2d 1011, 1016 (Bd. Pat. App. & Inter. 1986)

(Although an earlier case reversed a rejection because of unpredictability in the

field of monoclonal antibodies, the court found “

in this case

at the time

this

invention was made, one of ordinary skill in

the art would have been motivated to produce monoclonal antibodies specific for human

fibroplast interferon using the method of [the prior art] with a reasonable

expectation of success.”) (emphasis in original). For obviousness analysis under the

AIA, the relevant time is “before the effective filing date of the claimed

invention.”