Linda Messick v. Novartis Pharmaceuticals Corp.

FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

LINDA MESSICK, No. 13-15433

Plaintiff-Appellant,

D.C. No.

v. 3:12-cv-00693-SI

NOVARTIS PHARMACEUTICALS

CORPORATION, OPINION

Defendant-Appellee.

Appeal from the United States District Court

for the Northern District of California

Susan Illston, Senior District Judge, Presiding

Argued and Submitted

February 3, 2014—Seattle, Washington

Filed April 4, 2014

Before: Raymond C. Fisher, Ronald M. Gould,

and Morgan Christen, Circuit Judges.

Opinion by Judge Gould

2 MESSICK V. NOVARTIS PHARMACEUTICALS CORP.

SUMMARY*

Expert Testimony

The panel reversed the district court’s summary judgment

in favor of Novartis Pharmaceuticals Corporation because the

district court improperly excluded expert testimony.

Plaintiff offered Dr. Richard Jackson’s testimony on

osteonecrosis of the jaw and bisphosphonate-related

osteonecrosis of the jaw generally (“BRONJ”), and on the

causal link between plaintiff’s bisphosphonate treatment and

later development of BRONJ.

The panel held that the district court erred by excluding

the causation testimony offered by the plaintiff’s expert, Dr.

Jackson, when it found the testimony to be irrelevant and

unreliable. The panel held that Dr. Jackson’s testimony

indicated that plaintiff’s bisphosphonate use was a

substantial factor in her development of BRONJ, so the

testimony was relevant. The panel also held that the

testimony was reliable where Dr. Jackson testified a medical

condition was a substantial causative factor. The panel

concluded that Dr. Jackson’s expert testimony created a

genuine issue of material fact regarding the specific causal

link between plaintiff’s bisphosphonate treatment and her

development of osteonecrosis of the jaw.

*

This summary constitutes no part of the opinion of the court. It has

been prepared by court staff for the convenience of the reader.

MESSICK V. NOVARTIS PHARMACEUTICALS CORP. 3

COUNSEL

Martin N. Buchanan (argued), Law Offices of Martin N.

Buchanan, San Diego, California; John A. Girardi, Girardi

Keese, Los Angeles, California; John J. Vecchione, Valad &

Vecchione, PC, Fairfax, Virginia, for Plaintiff-Appellant.

Frank Leone (argued), Katharine R. Latimer, Rebecca A.

Womeldorf, Hollingsworth LLP, Washington, D.C., for

Defendant-Appellee.

OPINION

GOULD, Circuit Judge:

We consider when a district court should exclude expert

testimony at trial. Linda Messick contends that the district

court erred by excluding the causation testimony offered by

her expert, Dr. Richard Jackson, when it found the testimony

to be irrelevant and unreliable. Examining the district court’s

exclusion of expert testimony for an abuse of discretion, we

conclude that Dr. Jackson’s testimony was improperly

excluded, and we reverse and remand.

I

In August 2000, Linda Messick was diagnosed with

breast cancer. In response to her development of osteoporosis

after chemotherapy and steroid therapy, Messick was treated

with the drug Zometa from May 7, 2002 to November 14,

2002. Zometa is a bisphosphonate, a class of drug commonly

used to treat multiple myeloma. Such drugs are used to

reduce or eliminate the possibility of skeletal-related

4 MESSICK V. NOVARTIS PHARMACEUTICALS CORP.

degeneration and injuries to which cancer patients are

particularly susceptible. Novartis Pharmaceuticals

Corporation (“Novartis”) produces Zometa, which was

approved by the FDA in 2001 and 2002 for treating

hypercalcemia of malignancy and other conditions.

After Messick encountered several dental problems, two

oral specialists examined her in November 2005 and

discovered osteonecrosis near three of her teeth. Both doctors

treated her under the assumption that she was suffering from

bisphosphonate-related osteonecrosis of the jaw (“BRONJ”),

a condition recognized by the American Association of Oral

and Maxillofacial Surgeons (“AAOMS”). According to the

AAOMS, a BRONJ diagnosis is appropriate for patients with

(1) current or previous treatment with bisphosphonates,

(2) exposed bone in the maxillofacial region that has lasted

for more than eight weeks, and (3) no history of radiation

therapy to the jaw. Other potential causes of osteonecrosis of

the jaw (“ONJ”) may include: peridontal and dental disease,

osteomyelitis, corticosteroid use, cancer, radiation therapy,

compromised immunity, and trauma. While ONJ may be

caused by many factors, the AAOMS’s diagnostic definition

of BRONJ sets out its unique features: it lasts more than eight

weeks and is not related to radiation therapy. Messick’s

BRONJ healed between March and October 2008, about three

years after diagnosis. She and her husband brought suit

against Novartis for strict products liability, negligent

manufacture, negligent failure to warn, breach of express and

implied warranty, and loss of consortium.

To support her claims, Messick offered Dr. Jackson’s

testimony on ONJ and BRONJ generally, and on the causal

link between her bisphosphonate treatment and later

development of BRONJ. Dr. Jackson graduated from the

MESSICK V. NOVARTIS PHARMACEUTICALS CORP. 5

University of the Pacific’s School of Dentistry in 1974,

completed his oral and maxillofacial surgery residency in

1982, and became Board Certified in oral maxillofacial

surgery in 1984. He belongs to several dental and oral

maxillofacial professional groups, and has published and

lectured on a variety of topics over many years. Dr. Jackson

has extensive experience diagnosing and treating ONJ,

including ONJ in patients who had been treated with

bisphosphonates, and he is the primary oral and maxillofacial

surgeon managing ONJ in the Sacramento area.

While the action was pending in Multi-District Litigation

proceedings, Novartis filed a motion to exclude the specific

causation testimony of Messick’s experts and a motion

seeking summary judgment. After the case was remanded

and transferred, the district court granted those motions, and

Messick appeals the exclusion of Dr. Jackson’s causation

testimony and the ensuing grant of summary judgment to

Novartis.

II

We review a ruling on the admissibility of expert

testimony for an abuse of discretion, Primiano v. Cook,

598 F.3d 558, 563 (9th Cir. 2010), but review de novo the

“construction or interpretation of . . . the Federal Rules of

Evidence, including whether particular evidence falls within

the scope of a given rule.” United States v. Durham,

464 F.3d 976, 981 (9th Cir. 2006) (citations omitted).

The substantive issue here arises under the Federal Rules

of Evidence and California state products liability law.

Federal Rule of Evidence 702 governs expert testimony:

6 MESSICK V. NOVARTIS PHARMACEUTICALS CORP.

A witness who is qualified as an expert by

knowledge, skill, experience, training, or

education may testify in the form of an

opinion or otherwise if:

(a) the expert’s scientific, technical, or other

specialized knowledge will help the trier of

fact to understand the evidence or to

determine a fact in issue;

(b) the testimony is based on sufficient facts

or data;

(c) the testimony is the product of reliable

principles and methods; and

(d) the expert has reliably applied the

principles and methods to the facts of the

case.

Fed. R. Evid. 702. Although Rule 702 should be applied with

a “liberal thrust” favoring admission, Daubert v. Merrell Dow

Pharm., Inc., 509 U.S. 579, 588 (1993), it requires that

“[e]xpert testimony . . . be both relevant and reliable,” Estate

of Barabin v. AstenJohnson, Inc., 740 F.3d 457, 463 (9th Cir.

2014) (alteration and omission in original) (quoting United

States v. Vallejo, 237 F.3d 1008, 1019 (9th Cir. 2001)).

The relevancy bar is low, demanding only that the

evidence “logically advances a material aspect of the

proposing party’s case.” Daubert v. Merrell Dow Pharm.,

Inc., 43 F.3d 1311, 1315 (9th Cir. 1995) (“Daubert II”).

Relevancy depends on the particular law at issue because

“[e]xpert opinion testimony is relevant if the knowledge

MESSICK V. NOVARTIS PHARMACEUTICALS CORP. 7

underlying it has a valid connection to the pertinent inquiry.”

Primiano, 598 F.3d at 565. Here, California state products

liability law requires only that a plaintiff show that the

defendant’s conduct was “more likely than not” a substantial

factor in causing the injury in order to prove specific

causation. See Saelzler v. Advanced Grp. 400, 23 P.3d 1143,

1152 (Cal. 2001).

The district court excluded Dr. Jackson’s testimony as

irrelevant because of its view that his “differential diagnosis

only determines that Ms. Messick’s ONJ is related to her

bisphosphonate use, and he admits that a diagnosis of BRONJ

does not mean that bisphosphonates caused her ONJ.” The

district court applied too high a relevancy bar without

reference to California law. While Dr. Jackson never

explicitly stated that Messick’s bisphosphonate use caused

her BRONJ, he did say it was at least a substantial factor in

her development of BRONJ. Specifically, Dr. Jackson

equated Messick’s use of bisphosphonates leading to BRONJ

with the oxygen necessary to start a fire. Although one might

imagine more targeted testimony, Dr. Jackson’s testimony

indicates that Messick’s bisphosphonate use was a substantial

factor in her development of BRONJ, so his testimony is

relevant.

The district court also abused its discretion in finding Dr.

Jackson’s testimony to be unreliable. The reliability

threshold requires that the expert’s testimony have “a reliable

basis in the knowledge and experience of the relevant

discipline.” Kumho Tire Co., Ltd. v. Carmichael, 526 U.S.

137, 149 (1999) (citation and alterations omitted). The court

must determine “whether the reasoning or methodology

underlying the testimony is scientifically valid.” Daubert,

509 U.S. at 592–93.

8 MESSICK V. NOVARTIS PHARMACEUTICALS CORP.

We recently acknowledged the district court’s duty to “act

as a ‘gatekeeper’ to exclude junk science that does not meet

Federal Rule of Evidence 702’s reliability standards.”

Barabin, 740 F.3d at 463 (quoting Ellis v. Costco Wholesale

Corp., 657 F.3d 970, 982 (9th Cir. 2011)). To aid courts in

exercising this gatekeeping role, the Supreme Court has

suggested a non-exclusive and flexible list of factors that a

court may consider when determining the reliability of expert

testimony, including: (1) whether a theory or technique can

be tested; (2) whether it has been subjected to peer review

and publication; (3) the known or potential error rate of the

theory or technique; and (4) whether the theory or technique

enjoys general acceptance within the relevant scientific

community. Daubert, 509 U.S. at 592–94.

We and our sister circuits have held that a reliable

differential diagnosis may form the basis of an expert’s

causation testimony. See Clausen v. M/V NEW CARISSA,

339 F.3d 1049, 1057 (9th Cir. 2003); see also Ervin v.

Johnson & Johnson, Inc., 492 F.3d 901, 904 (7th Cir. 2007)

(noting that “[a] differential diagnosis satisfies a Daubert

analysis if the expert uses reliable methods”); McClain v.

Metabolife Int’l, Inc., 401 F.3d 1233, 1252 (11th Cir. 2005)

(detailing a reliable differential diagnostic process); Goebel

v. Denver & Rio Grande W. R.R. Co., 346 F.3d 987, 999

(10th Cir. 2003); Cooper v. Smith & Nephew, Inc., 259 F.3d

194, 202 (4th Cir. 2001) (holding that an expert’s opinion

based on a differential diagnosis is generally admissible);

Hardyman v. Norfolk & W. Ry. Co., 243 F.3d 255, 260 (6th

Cir. 2001) (“Differential diagnosis . . . is a standard scientific

technique of identifying the cause of a medical problem”);

Turner v. Iowa Fire Equip. Co., 229 F.3d 1202, 1208 (8th

Cir. 2000) (“[A] medical opinion about causation, based upon

a proper differential diagnosis, is sufficiently reliable to

MESSICK V. NOVARTIS PHARMACEUTICALS CORP. 9

satisfy Daubert.”); Baker v. Dalkon Shield Claimaints Trust,

156 F.3d 248, 253 (1st Cir. 1998) (stating that “‘differential

diagnosis’ is a standard medical technique”); Ambrosini v.

Labarraque, 101 F.3d 129, 140 (D.C. Cir. 1996) (describing

the appropriate use of differential diagnosis to prove specific

causation); McCullock v. H.B. Fuller Co., 61 F.3d 1038,

1043–44 (2d Cir. 1995); In re Paoli R.R. Yard PCD Litig.,

916 F.2d 829, 862 (3d Cir. 1990).1

When an expert rules out a potential cause in the course

of a differential diagnosis, the “expert must provide reasons

for rejecting alternative hypotheses using scientific methods

and procedures and the elimination of those hypotheses must

be founded on more than subjective beliefs or unsupported

speculation.” Clausen, 339 F.3d at 1058 (internal quotation

marks and citation omitted); Daubert II, 43 F.3d at 1318

(requiring explanations based on “scientifically valid

principles”). The district court abused its discretion in

excluding Dr. Jackson’s opinion, which stated that a patient

without cancer or exposure to radiation in the mouth area

would not develop ONJ lasting for years without IV

bisphosphonate treatments. It excluded the testimony

because Dr. Jackson “never explained the scientific basis for

this conclusion.” But Dr. Jackson repeatedly referred to his

own extensive clinical experience as the basis for his

differential diagnosis, as well as his examination of Messick’s

records, treatment, and history. Medicine partakes of art as

well as science, and there is nothing wrong with a doctor

relying on extensive clinical experience when making a

1

The Fifth Circuit is alone in not yet explicitly approving the use of

differential diagnosis, although it suggested in a recent case that a

differential diagnosis may be admissible to prove specific causation. See

Johnson v. Arkema, Inc., 685 F.3d 452, 467–68 (5th Cir. 2012).

10 MESSICK V. NOVARTIS PHARMACEUTICALS CORP.

differential diagnosis. Dr. Jackson also relied on the

AAOMS definition of BRONJ in reaching his diagnosis and

causation conclusions, which itself persuasively uses the three

elements to distinguish BRONJ from other ONJ or delayed

healing conditions. These sources form an appropriate

scientific basis for his opinions, and the district court abused

its discretion in concluding otherwise. See Primiano,

598 F.3d at 567 (admitting expert’s testimony with “sufficient

basis in education and experience”).

Although experts must provide scientifically sound

reasons for excluding potential causes, we have consistently

recognized the difficulties in establishing certainty in the

medical sciences. Id. at 565 (stating that “medical knowledge

is often uncertain” (quoting United States v. Sandoval-

Mendoza, 472 F.3d 645, 655 (9th Cir. 2006))). The Supreme

Court has similarly stressed that “it would be unreasonable to

conclude that the subject of scientific testimony must be

‘known’ to a certainty; arguably, there are no certainties in

science.” Daubert, 509 U.S. at 590.

Given the difficulties in establishing a medical cause and

effect relationship, “[c]ausation can be proved even when we

don’t know precisely how the damage occurred, if there is

sufficiently compelling proof that the agent must have caused

the damage somehow.” Kennedy v. Collagen Corp., 161 F.3d

1226, 1230 (9th Cir. 1998) (quoting Daubert II, 43 F.3d at

1314). Viewed in this context, it is perhaps unsurprising that

the AAOMS stated in a 2009 position paper that “the current

level of evidence does not fully support a cause-and-effect

relationship between bisphosphonate exposure and necrosis

of the jaws.” But the paper goes on to explain that while

“causality might never be proven, emerging experimental and

epidemiologic studies have established a firm foundation for

MESSICK V. NOVARTIS PHARMACEUTICALS CORP. 11

a strong association between monthly IV bisphosphonate

therapy and the development of BRONJ.”

Because of that inherent uncertainty, we do not require

that an expert be able to identify the sole cause of a medical

condition in order for his or her testimony to be reliable. It is

enough that a medical condition be a substantial causative

factor. We hold that the district court abused its discretion in

excluding Dr. Jackson’s causation testimony when it found

that testimony to be unreliable largely because Dr. Jackson

could not “determine in a patient who has multiple risk

factors at one time which of those particular risk factors is

causing [the ONJ].” Such an unduly exacting standard goes

beyond the district court’s proper gatekeeping role.

Dr. Jackson’s testimony should be admitted as relevant

and reliable. Remaining issues regarding the correctness of

his opinion, as opposed to its relevancy and reliability, are a

matter of weight, not admissibility. Kennedy, 161 F.3d at

1230–31. While the district court must act as a gatekeeper to

exclude “junk science” under Daubert, Federal Rule of

Evidence 702(a) includes within its scope all evidence that

would “help the trier of fact . . . to determine a fact in issue.”

A doctor using a differential diagnosis grounded in significant

clinical experience and examination of medical records and

literature can certainly aid the trier of fact and cannot be

considered to be offering “junk science.”

III

Summary judgment is proper when the moving party

shows “there is no genuine dispute as to any material fact and

the movant is entitled to judgment as a matter of law.” Fed.

R. Civ. P. 56(a). A court must view the evidence in the light

12 MESSICK V. NOVARTIS PHARMACEUTICALS CORP.

most favorable to the non-moving party, Scott v. Harris,

550 U.S. 372, 378 (2007), and “there must be evidence on

which the jury could reasonably find for the plaintiff,”

Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 252 (1986).

We review the district court’s grant of summary judgement

de novo. Lust ex rel. Lust v. Merrell Dow Pharm., Inc.,

89 F.3d 594, 596–97 (9th Cir. 1996).

Here, the district court based its grant of summary

judgment entirely on the fact that Messick had no expert

causation testimony once all of her experts had been

excluded. The admissibility, correctly viewed, of Dr.

Jackson’s expert testimony creates a genuine issue of material

fact regarding the specific causal link between Messick’s

bisphosphonates treatment and her development of ONJ. We

reverse the district court’s grant of summary judgment.

REVERSED AND REMANDED.