United States District Court, D. Arizona
CAMPBELL SENIOR UNITED STATES DISTRICT JUDGE.
have filed motions for summary judgment in these cases. The
motions are fully briefed, and no party has requested oral
argument. See Docs. 225, 228, 229. The Court will
grant summary judgment in favor of Defendants.
motion is based on the Court's previous ruling excluding
Plaintiffs' general causation experts under Federal Rule
of Evidence 702. Doc. 217; see also Davis v. McKesson
Corp., No. CV-18-1157-PHX-DGC, 2019 WL 3532179 (D. Ariz.
Aug. 2, 2019). The Court held that the general causation
opinions of Drs. Brent Wagner, Jody Tversky, and Margret
Whittaker are inadmissible, and that the opinions of Dr.
Raymond will be limited to the chemistry of GBCAs and
gadolinium. See id. Because none of Plaintiffs'
experts will be permitted to opine that GBCAs generally can
cause the range of symptoms claimed by plaintiffs, Defendants
argue that Plaintiffs cannot prove their claims and that
summary judgment is warranted.
argue that “[b]y imposing an initial ‘general
causation' requirement, the Court has imposed an
additional requirement that does not exist under Arizona
law.” Doc. 228 at 4. But Plaintiffs cite no Arizona law
in support of this argument, and the requirement of general
causation is widely recognized. See Grant v.
Bristol-Myers Squibb, 97 F.Supp.2d 986, 989 (D. Ariz.
2000) (“Causation must be general and specific; the
plaintiff must prove that the allegedly toxic substance is
capable of causing a particular injury in the general
population, and that the substance caused this particular
individual's injury.”); see also In re Mirena
IUD Prods. Liab. Litig., 169 F.Supp.3d 396, 435
(S.D.N.Y. 2016) (“General causation is whether a
substance is capable of causing a particular injury or
condition in the general population, while specific causation
is whether a substance caused a particular individual's
injury. In the absence of evidence of general causation,
evidence of specific causation is irrelevant.”)
(citations and footnotes omitted); Newkirk v. ConAgra
Foods, Inc., 727 F.Supp.2d 1006, 1030 (E.D. Wash. 2010),
aff'd, 438 Fed.Appx. 607 (9th Cir. 2011)
(“If a plaintiff is not able to establish general
causation, it is unnecessary to consider whether the
plaintiff can establish specific causation.”);
Raynor v. Merrell Pharms. Inc., 104 F.3d 1371, 1376
(D.C. Cir. 1997) (“[T]estimony on specific causation
had legitimacy only as follow-up to admissible evidence that
the drug in question could in general cause birth defects.
That first step, establishing a link between Bendectin and
human birth defects (general causation), is missing
next argue that they can establish causation through the
testimony of treating physicians who performed a differential
diagnosis of Plaintiffs' conditions. Doc. 228 at 4-5. But
none of these physicians was identified by Plaintiffs as an
expert on general causation. And as the cases cited above
show, Plaintiffs must prove both general and specific
causation - that GBCAs are capable of causing the wide range
of injuries claimed by Plaintiffs, and that they in fact
caused Plaintiff's injuries in this case. As one court
The process of differential diagnosis is undoubtedly
important to the question of “specific
causation”. If other possible causes of an injury
cannot be ruled out, or at least the probability of their
contribution to causation minimized, then the “more
likely than not” threshold for proving causation may
not be met. But, it is also important to recognize that a
fundamental assumption underlying this method is that the
final, suspected “cause” remaining after this
process of elimination must actually be capable of causing
the injury. That is, the expert must “rule in”
the suspected cause as well as “rule out” other
possible causes. And, of course, expert opinion on this issue
of “general causation” must be derived from a
scientifically valid methodology.
Cavallo v. Star Enter., 892 F.Supp. 756, 771 (E.D.
Va. 1995), aff'd in part, rev'd in part on other
grounds, 100 F.3d 1150 (4th Cir. 1996). As the Federal
Judicial Center's Reference Manual on Scientific Evidence
notes, “differential diagnoses generally are inadequate
without further proof of general causation[.]”
Reference Manual, at 613 n.194. (3d ed. 2011), available at
case, it is not at all apparent that GBCAs can cause
Plaintiff's range of symptoms. As the Court noted in its
previous order, “the FDA and every other regulatory and
medical body that has considered the question . . .
unanimously have found that there is not enough scientific
evidence to conclude that GBCAs cause GDD.”
Davis, 2019 WL 3532179, at *10. In such a setting,
expert testimony that GBCAs can cause Plaintiff's alleged
illnesses is essential to Plaintiff's case. Specific
causation opinions of individual doctors is not enough.
reliance on Messick v. Novartis Pharmaceuticals
Corp., 747 F.3d 1193 (9th Cir. 2014), for the
veracity of differential diagnosis, is not helpful.
Messick concerned a question of specific causation -
whether the plaintiffs illness was actually caused by her use
of bisphosphonates. The court of appeals noted that
“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.” Id. at 1197 (emphasis added). Because
the expert opined that the defendant's substances were a
substantial factor in the plaintiff's illness, the Ninth
Circuit held that summary judgment was improper: “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.” Id. at 1199 (emphasis
added). Thus, Messick is a specific causation case.
It does not hold that plaintiff-specific differential
diagnoses may satisfy the requirement of general causation.
Plaintiffs suggest that the Court erred in excluding their
general causation experts, but they provide no argument on
this issue. Doc. 228 at 3.
their general causation testimony inadmissible under Rule
702, Plaintiffs cannot prove at trial that GBCAs caused their
injuries. “[T]he plain language of Rule 56 mandates
the entry of summary judgment, after adequate time for
discovery and upon motion, against a party who fails to make
a showing sufficient to establish the existence of an element
essential to that party's case, and on which that party
will bear the burden of proof at trial.” Celotex
Corp. v. Catrett, 477 U.S. 317, 322 (1986). The Court
accordingly will grant summary judgment in favor of
1. Defendants' motions for summary judgment
(Davis Doc. 225, Fischer Doc. 142, and
Munnuru Doc. 148) are granted.
2. The Clerk is directed to enter judgment and terminate
these cases. Dated this 25th ...