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We saw the movie “Whiplash” last weekend.  In this Oscar contender, a drum student at a prestigious music conservatory seeks the approval of a harsh and punishing conductor, as well as a berth in the conductor’s competition jazz band.  The film is so tense and so consistently painful to watch that it would not be accurate to say that we “enjoyed” it, but we wouldn’t have missed it for the world.

Early in the movie, the conductor demands that the student play several measures over and over and over again in a relentless and seemingly futile attempt to find the correct tempo. In today’s decision out of the Denture Cream MDL pending in the Southern District of Florida (thanks to David Walz at Carlton Fields for sending it to us)  Plaintiffs are back, beating the same drum, in a repeat attempt to surmount defendant Procter & Gamble’s (“P & G’s”) Daubert challenges to their general causation experts.  In re Denture Cream Prods. Liab. Litig., No. 09-2051-MD-Altonaga, 2015 U.S. Dist. LEXIS 9653 (S.D. Fla. Jan.. 28, 2015).  In these cases, Plaintiffs allege that, with long-term use of Fixodent denture adhesive, the zinc in the product causes copper deficiency and, ultimately, a neurological condition known as copper deficiency myeloneuropathy (“CDM”).  In 2011, the court granted P & G’s Daubert motions to exclude Plaintiffs’ general causation experts. See In re Denture Cream Prods. Liab. Litig. (Chapman, et al. v. Procter & Gamble Distributing, LLC), 795 F. Supp. 2d 1345 (S.D. Fla. 2011), aff’d, 766 F.3d 1296 (11th Cir. 2014) (“Chapman’).  As we discussed at the time, the Court held, “[Plaintiffs’] theory is not ridiculous, but neither is it necessarily true; it is ripe for testing.  . . . [T]aking everything together, there is enough data in the scientific literature to hypothesize causation, but not to infer it.”  795 F. Supp. 2d at 1367 (emphasis in original).  This past September, as we reported here, the Eleventh Circuit affirmed the District Court’ Chapman decision.

“New,” but Not Improved

In what seems to be an MDL habit, Plaintiffs tried for a second bite at the apple, submitting what they termed “new evidence” in support of their general causation argument.  Plaintiffs argued that “the results of a recently-conducted Fixodent Blockade Study, along with new expert analysis . . . regarding Procter & Gamble’s in vivo pharmacokinetic studies and various in vitro  studies shows the zinc in Fixodent is bioavailable and chronic exposure can block copper uptake in the body.”  Denture Cream, 2015 U.S. Dist. LEXIS 9653 at *38.  Plaintiffs also submitted “new” epidemiological evidence they argued proved a statistically significant association between denture adhesive with zinc and CDM, “new” evidence of a dose-response relationship and several “new” case reports purporting to bolster their position on general causation.  Id. at *38-39.  In a thorough and thoughtful 64-page opinion, the Court held, resoundingly, that none of the “new” evidence passed Daubert muster.   Some highlights:

Physiological Process Involved/ Clinical Studies

To validate their argument that the zinc in Fixodent dissociates and becomes bioavailable, Plaintiffs relied upon a new Fixodent Blockade Study and two new sets of in vitro studies.

Defendants challenged “serious methodological flaws in the design, conduct and analysis of the Fixodent Blockade study, as well as the overall relevance of the study’s findings to the question of general causation, because the study does not address dose − the amount, frequency  or duration of Fixodent use needed to cause a copper deficiency, much less a myeloneuropathy.”  Id. at *57 (internal quotation marks and citations omitted).   The Court agreed. describing mid-stream changes in the statistical analysis that deviated from the approved protocol and “[made] the data fit Plaintiff’s hypothesis,” id. at *60-61, “[turning] a ‘not significant’ study result into a ‘quite impressive’ study result,” Id. at *63-64.  The Court concluded that the methodological flaws, “taken together,” demanded a finding that “the Fixodent Blockade Study is not “good science” and is not admissible.”  Id. at * 68 (citation to Daubert omitted).

The Court next analyzed Plaintiffs’ in vitro studies.   With regard to the first, the Court commented, “In place of details and analysis, [the] one page in vitro report consists of conclusory statements . . . devoid of factual or analytical support.”  Id. at *72 (citations omitted).  Among other methodological flaws, the report failed “to explain the relevancy of the in vitro studies to humans or to account for factors needed to make a proper extrapolation . . . .”  Id.  The Court concluded that the report was unreliable, based on its “severe inadequacies” and its failure to consider how the in vitro release of zinc “correlated to actual zinc ion release in the human body.”  Id. at *74.  The second set of in vitro studies failed to support plaintiff’s bioavailability argument and actually demonstrated “that taking more and more Fixodent may not expose a person to more and more zinc.” Id. at *91.  “In short,” the Court concluded, “Plaintiffs are not much better off than they were at the time of Chapman.”  Id.

Epidemiological Evidence and Background Risk of Disease

The Court dispatched Plaintiffs’ epidemiological evidence with similar force, finding that the results of their expert’s retrospective cohort study “were arrived at using cherry-picked data and flawed methodology.” Id. at *116.  The Court also noted that “[t]he absence of background risk of CDM . . . remains a substantial weakness in Plaintiffs’ experts’ causal reasoning.”   The Court reiterated the Chapman conclusion that background risk is important because, “[w]ithout a baseline, any incidence may be a coincidence.”  Id. at *118 (citation omitted).

Dose-Response Relationship

Noting that “even Plaintiffs concede” that Fixodent “is safe when used in moderate amounts,” id.  at *119-20 (citation omitted), the Court turned to the three experts Plaintiffs proffered on the subject of dose-response relationship.  The first relied heavily on governmental standards, which the Court recognized were “conservative” and did not reflect the judicial “more likely than not” standard.  Id. at *126-129.  We addressed the same point here.  That expert also cited research relying on case reports and adverse event reports.  The Court concluded that “even ‘well-documented’ cases” are “not reliable enough, by themselves, to demonstrate the causal link the Plaintiffs assert because they report symptoms observed in a single patient in an uncontrolled context.”  Id. at *134 (citation omitted).  This one goes on our adverse events cheat sheet.
The second expert’s report, based on research about a different copper-related disease than that alleged by the Plaintiffs, “leaves the same large analytical gap the Court previously noted between a temporary negative copper balance and severe copper deficiency with neurological symptoms.”  Id. at *135 (citation omitted).
Finally, “consistent with [their] imprecise approach to general causation evidence,” id. at *136, Plaintiffs included a dose-response expert who “ha[d] no opinion regarding copper, copper retention, copper deficiency and zinc, or neurological effects of copper,” id. at *136, and whose opinion made “no attempt to connect the act of exceeding government recommended daily allowances for zinc with copper deficiency or CDM.”  Id. at *136-137. The increasingly impatient Court concluded that the absence of reliable dose-response evidence “leaves considerable analytical gaps in Plaintiffs’ general causation theory.”  Id. at *138.

In sum, the Court held that Plaintiffs’ general causation experts possessed “no analytical epidemiological evidence, no evidence of background risk, and no knowledge of dose-response.” Id. at *141.  As such, the Court granted P & G’s motions, concluding, “To admit the Plaintiffs’ evidence, the Court would have to make several scientifically unsupported ‘leaps of faith’ in the causal chain.  The Daubert rule requires more.”  Id. at *142-43 (citation omitted).In Whiplash, after repeating the same mistake too many times, the young student narrowly avoids a chair the irate conductor has thrown at his head.  In this case, the Denture Cream Plaintiffs forgot to duck.