- 47 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

Aimee Freeman, appellant, v. 

Hoffman-La Roche, Inc., and

Roche Laboratories, Inc., 

appellees.

___ N.W.2d ___

Filed May 18, 2018. No. S-17-800.

1. Trial: Expert Witnesses: Appeal and Error. An appellate court reviews 

de novo whether the trial court applied the correct legal standards for 

admitting an expert’s testimony.

2. ____: ____: ____. When the trial court has not abdicated its gatekeeping 

function under Schafersman v. Agland Coop, 262 Neb. 215, 631 N.W.2d 

862 (2001), an appellate court reviews the trial court’s decision to admit 

or exclude the evidence for an abuse of discretion.

3. Judgments: Words and Phrases. An abuse of discretion occurs when a 

trial court’s decision is based upon reasons that are untenable or unreasonable or if its action is clearly against justice or conscience, reason, 

and evidence.

4. Summary Judgment: Appeal and Error. An appellate court will 

affirm a lower court’s grant of summary judgment if the pleadings and 

admitted evidence show that there is no genuine issue as to any material 

facts or as to the ultimate inferences that may be drawn from those facts 

and that the moving party is entitled to judgment as a matter of law.

5. Trial: Expert Witnesses. Under the framework established by Daubert 

v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S. Ct. 2786, 

125 L. Ed. 2d 469 (1993), and Schafersman v. Agland Coop, 262 Neb. 

215, 631 N.W.2d 862 (2001), if an expert’s opinion involves scientific or 

specialized knowledge, a trial court must determine whether the reasoning or methodology underlying the testimony is valid (reliable). It must 

also determine whether that reasoning or methodology can be properly 

applied to the facts in issue.

6. ____: ____. A trial court can consider several nonexclusive factors in 

determining the reliability of an expert’s opinion: (1) whether a theory 

Nebraska Supreme Court Online Library

www.nebraska.gov/apps-courts-epub/

07/13/2018 12:09 AM CDT
- 48 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

or technique can be (and has been) tested; (2) whether it has been 

subjected to peer review and publication; (3) whether, in respect to a 

particular technique, there is a high known or potential rate of error; (4) 

whether there are standards controlling the technique’s operation; and 

(5) whether the theory or technique enjoys general acceptance within a 

relevant scientific community.

7. Expert Witnesses. Absent evidence that an expert’s testimony grows 

out of the expert’s own prelitigation research or that an expert’s research 

has been subjected to peer review, experts must show that they reached 

their opinions by following an accepted method or procedure as it is 

practiced by others in their field.

8. Courts: Expert Witnesses. The objective of the trial court’s gatekeeping responsibility is to make certain that an expert, whether basing 

testimony upon professional studies or personal experience, employs in 

the courtroom the same level of intellectual rigor that characterizes the 

practice of an expert in the relevant field.

9. Evidence: Proof. Failure of proof concerning an essential element of the 

nonmoving party’s case necessarily renders all other facts immaterial.

Appeal from the District Court for Douglas County: Leigh

Ann Retelsdorf, Judge. Affirmed.

Jeffrey A. Silver, and Walter G. Campbell, Jr., and Noreek 

Davitian, of Krupnick, Campbell, Malone, Buser, Slama, 

Hancock & Liberman, P.A., and Michael D. Hook, of Hook, 

Bolton, Mitchell, Kirkland & McGhee, P.A., for appellant.

Jill Vinjamuri Gettman, of Gettman & Mills, L.L.P., Michael 

X. Imbroscio and Paul W. Schmidt, of Covington & Burling, 

L.L.P., and Colleen M. Hennessey, of Peabody & Arnold, 

L.L.P., for appellees.

Heavican, C.J., Miller-Lerman, Cassel, Stacy, and Funke, 

JJ., and Riedmann, Judge, and Martinez, District Judge.

Cassel, J.

I. INTRODUCTION

In this product liability action, the district court excluded the 

claimant’s expert’s testimony regarding causation. Summary 

judgment for the manufacturer and distributor followed. On 
- 49 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

appeal, the claimant asserts that the exclusion exceeded the 

court’s “gatekeeping” function. Because the record supports 

the court’s conclusion that the expert’s methodology was unreliable and conclusion-driven, we find no abuse of discretion in 

the exclusion and affirm the judgment.

II. BACKGROUND

Aimee Freeman brought a product liability action against 

Hoffman-La Roche, Inc., and Roche Laboratories, Inc. (collectively Roche), alleging that she developed a chronic medical condition and other side effects as a result of ingesting 

Accutane. Accutane, also known as isotretinoin, is a pharmaceutical drug manufactured and distributed by Roche for the 

treatment of chronic acne.

Freeman initially alleged that she suffered from ulcerative 

colitis—a type of inflammatory bowel disease (IBD)—which 

is a chronic condition characterized by ulceration of the colon 

and rectum. However, the expert witnesses generally agreed 

that Freeman had actually developed Crohn’s disease—another 

type of IBD—which causes chronic inflammation and ulcers in 

any part of the gastrointestinal tract and tends to extend beyond 

and penetrate all layers of the gastrointestinal tract wall. Both 

ulcerative colitis and Crohn’s disease share many of the same 

symptoms. But, as Freeman acknowledges, “there are differences in the clinical presentation of the disease[s] and the triggers statistically associated for developing [them].”1

As a material element for her product liability claims, 

Freeman was required to prove her injury was proximately 

caused by Roche’s actions or inactions in manufacturing and 

distributing isotretinoin.2 In other words, she had to show that 

ingesting isotretinoin could cause the development of Crohn’s 

1 Brief for appellant at 6.

2 See, Freeman v. Hoffman-La Roche, Inc., 260 Neb. 552, 618 N.W.2d 827 

(2000); King v. Burlington Northern Santa Fe Ry. Co., 277 Neb. 203, 762 

N.W.2d 24 (2009).
- 50 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

disease and that her ingestion of isotretinoin did in fact cause 

her to develop the disease.3 In order to meet this burden of 

proof, Freeman intended to call Dr. David B. Sachar as an 

expert witness to render opinions on the general and specific 

causation of her Crohn’s disease.

Before trial, Roche filed a motion in limine seeking to preclude Sachar’s testimony and challenged his opinions under 

the Daubert/Schafersman framework.4 They did not suggest 

that Sachar was unqualified to testify as an expert; rather, they 

alleged that his opinions on causation were not based upon a 

properly applied and reliable methodology.

After conducting a Daubert/Schafersman hearing, the district court entered a 42-page order precluding Sachar from 

testifying. In its order, the court summarized the admitted evidence as well as the conclusions derived from the 

evidence. It also highlighted the key testimony of each of 

the experts concerning the evidence presented. In reviewing 

Sachar’s analysis of and reliance on the different types of 

evidence, the court found Sachar’s methodology was unreliable due to his inconsistent approach criticizing studies 

adverse to his theory. It further found that his “unabashedly 

cherry-pick[ing] supporting studies from an overwhelming 

contrary body of literature indicated, in no uncertain terms, 

his methodology was conclusion-driven.” Additional facts 

and findings from the hearing and order are set forth in our 

analysis below.

After the court sustained the motion in limine, Roche filed 

a motion for summary judgment. The district court found 

that with the exclusion of Sachar’s testimony, Freeman had 

no admissible expert evidence to establish a causal association between Accutane and IBD. Because Freeman could not 

3 See King v. Burlington Northern Santa Fe Ry. Co., supra note 2.

4 See, Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 

S. Ct. 2786, 125 L. Ed. 2d 469 (1993); Schafersman v. Agland Coop, 262 

Neb. 215, 631 N.W.2d 862 (2001).
- 51 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

raise a genuine dispute of material fact on causation without expert testimony, the court granted the motion for summary judgment.

Freeman timely appealed.

III. ASSIGNMENTS OF ERROR

Freeman assigns, restated and combined, that the district 

court erred in (1) concluding that her expert witness’ opinions 

were not based upon valid reasoning or methodology; (2) precluding the testimony of her expert witness; and (3) granting 

summary judgment in favor of Roche on the issue of general 

causation when her expert witness’ testimony, if allowed into 

evidence, would create an issue of fact on that issue.

IV. STANDARD OF REVIEW

[1-3] An appellate court reviews de novo whether the trial 

court applied the correct legal standards for admitting an 

expert’s testimony.5 When the trial court has not abdicated its 

Schafersman6 gatekeeping function, an appellate court reviews 

the trial court’s decision to limit or exclude the evidence for 

an abuse of discretion.7 An abuse of discretion occurs when a 

trial court’s decision is based upon reasons that are untenable 

or unreasonable or if its action is clearly against justice or conscience, reason, and evidence.8

[4] An appellate court will affirm a lower court’s grant of 

summary judgment if the pleadings and admitted evidence 

show that there is no genuine issue as to any material facts 

or as to the ultimate inferences that may be drawn from those 

facts and that the moving party is entitled to judgment as a 

matter of law.9

5 King v. Burlington Northern Santa Fe Ry. Co., supra note 2.

6 Schafersman v. Agland Coop, supra note 4.

7 Hemsley v. Langdon, 299 Neb. 464, 909 N.W.2d 59 (2018).

8 Putnam v. Scherbring, 297 Neb. 868, 902 N.W.2d 140 (2017).

9 Edwards v. Hy-Vee, 294 Neb. 237, 883 N.W.2d 40 (2016).
- 52 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

V. ANALYSIS

1. Exclusion of Expert Testimony

Freeman argues that the district court deviated from its 

proper gatekeeping function and improperly determined the 

weight and credibility of Sachar’s testimony. She does not 

contend that the court abdicated its role,10 but, rather, that it 

required too much.11 She suggests that Sachar’s opinions were 

based on good grounds and should have been admitted to be 

evaluated by a jury. We disagree.

[5] Under our Daubert/Schafersman framework, if an 

expert’s opinion involves scientific or specialized knowledge, 

a trial court must determine whether the reasoning or methodology underlying the testimony is valid (reliable).12 It must 

also determine whether that reasoning or methodology can be 

properly applied to the facts in issue.13

[6] A trial court can consider several nonexclusive factors in determining the reliability of an expert’s opinion: (1) 

whether a theory or technique can be (and has been) tested; 

(2) whether it has been subjected to peer review and publication; (3) whether, in respect to a particular technique, there 

is a high known or potential rate of error; (4) whether there 

are standards controlling the technique’s operation; and (5) 

whether the theory or technique enjoys general acceptance 

within a relevant scientific community.14 But, as we have previously stated, different factors may prove more significant 

in different cases, and additional factors may prove relevant 

under particular circumstances.15

10 See Hemsley v. Langdon, supra note 7.

11 See King v. Burlington Northern Santa Fe Ry. Co., supra note 2.

12 State v. Braesch, 292 Neb. 930, 874 N.W.2d 874 (2016).

13 Id.

14 Id.

15 See Epp v. Lauby, 271 Neb. 640, 715 N.W.2d 501 (2006).
- 53 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

(a) Accepted Methodology

[7] Absent evidence that an expert’s testimony grows 

out of the expert’s own prelitigation research or that an 

expert’s research has been subjected to peer review, experts 

must show that they reached their opinions by following an 

accepted method or procedure as it is practiced by others in 

their field.16

In this case, Sachar acknowledged that he had not written or published his opinions concerning isotretinoin use and 

Crohn’s disease—limited to the colon or as a whole—despite 

writing over 220 published papers on IBD and approximately 

60 books or book chapters on gastroenterology. He reached 

his opinion by employing what we have characterized as a 

“weight-of-the-evidence methodology,”17 by reviewing data 

from different scientific fields, including animal tests, case 

reports, and epidemiological studies.

We have already determined that the weight-of-the-evidence 

methodology is a generally accepted method of determining causation.18 Therefore, the focus shifted to whether the 

method was reliably applied. We limit our discussion to the 

factors that help to inform this analysis.

(b) Consistent Standards

Sachar opined that isotretinoin use was “a risk factor for the 

onset, development, triggering, [and] exacerbation of ulcerative colitis.” And although he recognized that no study specifically determined that the same could be said for Crohn’s 

disease, he theorized that isotretinoin would also be a risk factor for Crohn’s disease of the colon, which he suggested was 

the appropriate diagnosis for Freeman’s condition.

16 State v. Braesch, supra note 12.

17 See King v. Burlington Northern Santa Fe Ry. Co., supra note 2, 277 Neb. 

at 221, 762 N.W.2d at 39.

18 See id.
- 54 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

In reaching this conclusion, Sachar discredited all but one 

of the epidemiological studies finding no significant relation between isotretinoin use and IBD, because they did not 

distinguish between IBD as a whole and ulcerative colitis 

and Crohn’s disease. Similarly, he found those studies that 

reported no association between isotretinoin use and Crohn’s 

disease “wastes everybody’s time,” because they did not 

separately consider the different manifestations of Crohn’s 

disease. However, Sachar acknowledged that the scientific 

community has yet to agree that a distinction between the 

different manifestations of Crohn’s disease is necessary when 

studying Crohn’s disease as a whole. And although he admitted that Crohn’s disease has a different clinical presentation 

and different causes than ulcerative colitis, Sachar relied on 

the one epidemiological study concerning ulcerative colitis as “the closest surrogate we have to Crohn’s disease of 

the colon.”

Based upon this reasoning, Sachar disregarded what the 

other two expert witnesses found to be the most probative evidence. And one of those experts testified that Sachar’s reasons 

were not supported by the scientific community. Significantly, 

Sachar did not require the same narrow focus on Crohn’s 

disease of the colon in data from other scientific sources. 

In fact, in reviewing case reports, Sachar relied upon case 

reports of Crohn’s disease and did not limit his examination to 

only those cases where disease of the colon was specifically 

reported. This suggests that Sachar was unduly critical of the 

majority of the studies which were adverse to his theory. And 

as the district court noted, it indicates that his methodology 

was conclusion-driven.

[8] While other factors may also suggest that Sachar’s methodology was unreliably applied, we need not address them. 

The objective of the trial court’s gatekeeping responsibility is 

to make certain that an expert, whether basing testimony upon 

professional studies or personal experience, employs in the 
- 55 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field.19 Clearly, 

cherrypicking studies from an overwhelmingly contrary body 

of literature without valid, supporting reasons for why the 

other studies were disregarded does not meet the standard of 

intellectual rigor required of expert witnesses. Accordingly, 

we cannot find that the district court abused its discretion in 

excluding Sachar’s testimony.

2. Summary Judgment

[9] Two principles of law control our review of the summary judgment that followed. For one of them, we recall 

the well-known standard applicable to summary judgments, 

which we already have stated above. The other is a corollary 

of the first: Failure of proof concerning an essential element 

of the nonmoving party’s case necessarily renders all other 

facts immaterial.20

Freeman was required to establish causation to prevail at 

trial. Without Sachar’s expert testimony, she could not meet this 

burden of proof. At oral argument, Freeman’s counsel seemed 

to suggest otherwise. Specifically, counsel stated, “Roche, 

in their internal documents, admits there’s an association—a 

causal association. The document I’m referring to is signed 

off by their Global Head of Safety. . . . Their very label on 

this drug says Accutane is associated with inflammatory bowel 

disease.” To the extent that these documents are included in 

our record, we find no admission of a causal association. In 

fact, the cited document mentioned only an association, not 

a causal association. Similarly, the label states merely that 

“Accutane has been temporally associated with inflammatory 

bowel disease.” And an association does not necessarily equate 

to causation.

19 See Schafersman v. Agland Coop, supra note 4.

20 Roskop Dairy v. GEA Farm Tech., 292 Neb. 148, 871 N.W.2d 776 (2015).
- 56 -

Nebraska Supreme Court Advance Sheets

300 Nebraska Reports

FREEMAN v. HOFFMAN-LA ROCHE, INC.

Cite as 300 Neb. 47

Because there was no genuine issue of fact as to the element of causation, Roche was entitled to judgment as a matter 

of law.

VI. CONCLUSION

The district court did not abuse its discretion in excluding 

the expert testimony after finding that the expert’s methodology was unreliable and conclusion-driven. With the exclusion 

of this expert testimony, there remained no issue of material 

fact. Consequently, the district court did not err in granting 

summary judgment in favor of Roche. We affirm.

Affirmed.