ADDITIONAL CASES Coning, Plaintiffs-Appellants, v. Bayer Pharma Ag, Bayer Oy, Bayer Healthcare Pharmaceuticals Inc., Defendants-Appellants* ON APPEAL FROM THE UNITED STATES DISTRICT COURT FOR THE SOUTHERN DISTRICT OF NEW YORK Appeal from a judgment of the United States District Court for the Southern District of New York (Engelmayer, J.) granting summary judgment in favor of defendants-appellees dismissing plaintiffs-appellants’ products liability claims after precluding, pursuant to Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the opinions of plaintiffs-appellants’ expert witnesses as to general causation. AFFIRMED. PER CURIAM Plaintiffs-appellants (“plaintiffs”) appeal the district court’s judgment entered June 21, 2019, in favor of defendant-appellee Bayer Pharmaceuticals Inc. (“Bayer”) and dismissing all claims. By opinion and order entered October 24, 2018, the district court granted Bayer’s motion pursuant to Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), to exclude the testimony of all of plaintiffs’ experts. In re Mirena IUS Levonorgestrel-Related Prods. Liab. Litig., 341 F. Supp. 3d 213 (S.D.N.Y. 2018). By opinion and order entered June 11, 2019, the district court granted Bayer’s motion for summary judgment on the ground that the remaining evidence was insufficient to establish general causation, or in other words, that plaintiffs failed to offer evidence to suggest that Bayer’s product is capable of causing the type of injuries from which plaintiffs claim to suffer. In re Mirena IUS Levonorgestrel-Related Prods. Liab. Litig., 387 F. Supp. 3d 323 (S.D.N.Y. 2019). On appeal, plaintiffs argue that the district court improperly excluded the opinions of their experts on general causation, erred in granting summary judgment for Bayer, and denied plaintiffs their right to obtain and produce evidence in discovery. We reject plaintiffs’ arguments, and for substantially the reasons set forth in the district court’s thorough opinions, we affirm its judgment. BACKGROUND The Mirena Intrauterine System (“Mirena”) is a plastic T-shaped intrauterine device (“IUD”), manufactured by Bayer, that releases a synthetic steroid hormone called levonorgestrel (“LNG”) into the uterus to prevent pregnancy. Plaintiffs are women from across the country who allege that they developed idiopathic intracranial hypertension (“IIH”) as a result of using Mirena.1 The Judicial Panel on Multidistrict Litigation (“JPML”) consolidated plaintiffs’ cases in the Southern District of New York for pretrial proceedings, where plaintiffs filed their consolidated amended complaint alleging negligence, manufacturing defect, design defect, failure to warn, breach of implied and express warranties, negligent misrepresentation, fraudulent misrepresentation, fraud, and state consumer fraud violations. On June 21, 2017, the district court entered a scheduling order giving “priority” to the issue of “whether plaintiffs have admissible evidence sufficient to establish general causation of the harms alleged.” S. App’x at 212. Accordingly, the district court scheduled a hearing pursuant to Daubert, “as to all expert evidence bearing on general causation.” S. App’x at 214. The district court held its Daubert hearing April 9-11, 2018, at which plaintiffs and Bayer put forward seven and twelve expert witnesses, respectively, on the issue of general causation. Plaintiffs’ experts were (1) Dr. Vincenzo Salpietro, (2) Dr. Conrad Johanson, (3) Dr. Philip Darney, (4) Dr. Lemuel Moyé, (5) Dr. James Wheeler, (6) Dr. Frederick Fraunfelder, and (7) Dr. Laura Plunkett. On October 24, 2018, the district court issued its 156-page opinion and order granting Bayer’s Daubert motion as to all of plaintiffs’ experts and denying as moot plaintiffs’ motion to preclude Bayer’s experts. Bayer then moved for summary judgment, arguing that without expert witnesses, plaintiffs had insufficient evidence to establish general causation. On June 11, 2019, the district court granted Bayer’s summary judgment motion, and on June 21, 2019, entered judgment and closed all of the cases in the MDL. This appeal followed. DISCUSSION I. Standard of Review We review a “district court’s decision to admit or exclude expert testimony under a highly deferential abuse of discretion standard.” Zuchowicz v. United States, 140 F.3d 381, 386 (2d Cir. 1998) (citing Gen. Elec. Co. v. Joiner, 522 U.S. 136, 141 (1997)). “A decision to admit or exclude expert scientific testimony is not an abuse of discretion unless it is manifestly erroneous.” Amorgianos v. Nat’l R.R. Passenger Corp., 303 F.3d 256, 265 (2d Cir. 2002) (internal quotation marks omitted). “Significantly, the abuse of discretion standard ‘applies as much to the trial court’s decisions about how to determine reliability as to its ultimate conclusion.’” Id. (quoting Kumho Tire Co. v. Carmichael, 526 U.S. 137, 152 (1999)). Thus, the trial judge has broad discretion in determining “what method is appropriate for evaluating reliability under the circumstances of each case.” Id. We review a grant of summary judgment de novo, “construing the facts in the light most favorable to the non-moving party and drawing all reasonable inferences in that party’s favor.” Burns v. Martuscello, 890 F.3d 77, 83 (2d Cir. 2018). II. Daubert Under Federal Rule of Evidence 702, lower courts perform a “gatekeeping” function and are charged with “the task of ensuring that an expert’s testimony both rests on a reliable foundation and is relevant to the task at hand.” Daubert, 509 U.S. at 597. But while “Rule 702 sets forth specific criteria for the district court’s consideration, the Daubert inquiry is fluid and will necessarily vary from case to case.” Amorgianos, 303 F.3d at 266. Similarly, while the Court in Daubert identified four factors bearing on reliability that district courts may consider — (1) whether a theory or technique “can be (and has been) tested”; (2) “whether the theory or technique has been subjected to peer review and publication”; (3) a technique’s “known or potential rate of error,” and “the existence and maintenance of standards controlling the technique’s operation”; and (4) whether a particular technique or theory has gained “general acceptance” in the relevant scientific community, Daubert, 509 U.S. at 593-94 — the Court cautioned that “[t]hese factors do not constitute…a ‘definitive checklist or test.’” Amorgianos, 303 F.3d at 266 (quoting Daubert, 509 U.S. at 593). So long as “an expert’s analysis [is] reliable at every step,” it is admissible. Id. at 267. Plaintiffs argue that the district court abused its discretion by (1) focusing on plaintiffs’ experts’ conclusions rather than their methodologies, (2) requiring the experts to back their opinions with published studies that definitively supported their conclusions, and (3) taking a “hard look” at the experts’ methodology. Appellant Br. at 14-15. Each argument is rejected. We start with plaintiffs’ third argument: that the district court erred by taking a “hard look” at each expert’s methodology. This argument is central to plaintiffs’ appeal, as they argue the district court’s analysis of each expert was too searching. But as noted, an expert’s methodology must be reliable at every step of the way, and “[i]n deciding whether a step in an expert’s analysis is unreliable, the district court should undertake a rigorous examination of the facts on which the expert relies, the method by which the expert draws an opinion from those facts, and how the expert applies the facts and methods to the case at hand.” Amorgianos, 303 F.3d at 267 (emphasis added). Accordingly, not only was it appropriate for the district court to take a hard look at plaintiffs’ experts’ reports, the court was required to do so to ensure reliability. Plaintiffs’ contention that the district court impermissibly focused on plaintiffs’ experts’ conclusions instead of their methodologies is similarly unavailing. The district court provided in-depth analysis of whether the experts applied their methodologies reliably. S. App’x at 52 (discussing in detail how Moyé’s analysis “is flawed by serious methodological deficiencies”), 70-71 (explaining the “number of methodological flaws” with Plunkett’s analysis), 84 (Wheeler’s methodology was “flawed in multiple respects”), 102 (discussing the “hallmarks of unreliability” throughout Fraunfelder’s analysis), 119, 121 (noting that Darney’s report suffers from a broad overarching lapse of methodology and two speculative leaps rendering it unreliable), 139 (“infirmities precluding a finding of reliability as to three of the four steps” of Johanson’s method), 149 (Salpietro’s opinion “does not meet any of the Daubert criteria for reliability”). Plaintiffs may (and do) challenge whether the reliability analysis was correct, but plaintiffs have no basis to argue that the district court did not engage in a detailed analysis of their experts’ methodologies. Next, plaintiffs argue that the district court erred by requiring the experts to back their opinions with studies definitively supporting their conclusions. Even assuming the district court did impose such a requirement, it did not err in doing so. We have held that “[w]here an expert otherwise reliably utilizes scientific methods to reach a conclusion, lack of textual support may go to the weight, not the admissibility of the expert’s testimony.” Amorgianos, 303 F.3d at 267 (internal quotation marks and citations omitted). In other words, an expert need not back his or her opinion with published studies that support his or her conclusion if he or she has utilized reliable scientific methods to reach that conclusion. But here, because the district court found that plaintiffs’ experts did not “otherwise reliably utilize[] scientific methods,” and the conclusions were not supported by other studies, the experts’ reports were properly excluded. Id.; see Joiner, 522 U.S. at 146. Further, the court was well within its discretion to consider whether plaintiffs’ experts’ conclusions were generally accepted by the scientific community. The “general acceptance” of an expert’s conclusion is one of the four enumerated considerations in Daubert, 509 U.S. at 594, and while a court need not consider the Daubert factors, it does not abuse its discretion in doing so. In sum, the district court appropriately undertook a rigorous review of each of plaintiffs’ experts, and based on that review reasonably found that the experts’ methods were not sufficiently reliable and that their conclusions were not otherwise supported by the scientific community. Accordingly, the district court did not abuse its discretion in precluding the experts’ conclusions. III. Summary Judgment We turn to whether the court correctly granted summary judgment in favor of Bayer. We conclude that it did, for we agree that no reasonable juror could find that it was more likely than not that general causation had been established based on plaintiffs’ admissible evidence. State law controls on the question of what evidence is necessary to prove an element of a state law claim, such as general causation. See Amorgianos, 303 F.3d at 268. The district court concluded that all fifty states “require some evidence of general causation in products liability cases involving complex products liability (or medical) issues.” S. App’x at 175. This question was presented to us in a previous MDL regarding Mirena, and we affirmed the district court’s holding to that effect there. See Mirena MDL Plaintiffs v. Bayer HealthCare Pharms. Inc. (In re Mirena IUD Prods. Liability Litig. I), 713 F. App’x 11, 15-16 (2d Cir. 2017) (summary order). Plaintiffs attack that conclusion from the previous Mirena IUD MDL case and the district court’s holding below, but, as the district court noted and is still true now, plaintiffs have failed to point to any state that does not have a general causation requirement for the type of claims at issue here. Rather, plaintiffs argue that some states allow evidence on specific causation before or in conjunction with the presentment of evidence on general causation, but that is a challenge to the way in which the district court managed the litigation — which is discussed below — not the substantive state law that the district court applied. Accordingly, we are not persuaded that the district court erred in holding that there is a general causation requirement across all states. Alternatively, plaintiffs argue that even if they were required to satisfy a threshold general causation showing, their failure to do so was because the district court prevented them from obtaining and presenting such evidence. We also reject this argument. “A district court has wide latitude to determine the scope of discovery, and we ordinarily defer to the discretion of district courts regarding discovery matters. A district court abuses its discretion only when the discovery is so limited as to affect a party’s substantial rights.” Twinam v. Dow Chem. Co. (In re Agent Orange Prod. Liab. Litig.), 517 F.3d 76, 103 (2d Cir. 2008) (internal quotation marks and alteration omitted). In other words, “[a] party must be afforded a meaningful opportunity to establish the facts necessary to support his claim.” Id. Plaintiffs first argue that the district court erred in granting Bayer’s summary judgment motion for lack of evidence of general causation because the district court excluded all of their experts’ reports instead of just portions of them. Plaintiffs therefore are suggesting that the testimony that they believe should have been carved out as admissible would have been sufficient to establish general causation. But plaintiffs have not explained which portions of their experts’ reports should have been carved out as admissible (assuming, as the plaintiffs ask us to on this issue, that the district court’s Daubert analysis was correct but warranted exclusion of only portions of their experts’ reports) nor do they explain how those portions would have established general causation. We cannot credit a nonmovant’s merely speculative assertion that some evidence that they have not specifically identified could have created a genuine dispute regarding general causation. See DiStiso v. Cook, 691 F.3d 226, 229-30 (2d Cir. 2012). Plaintiffs next argue that the district court erred in precluding differential-diagnosis evidence, which they argue would have established that Mirena may have been the likely cause of their IIH.2 But whether Mirena actually caused plaintiff’s IIH is an issue of specific causation, not general causation, the latter of which concerns whether Mirena is even capable of causing IIH. See Amorgianos, 303 F.3d at 268. And while we have declined to adopt a bright-line rule that “a differential diagnosis may never provide a sufficient basis for an opinion as to general causation,” we have explained that the “district judge has broad discretion in determining whether in a given case a differential diagnosis is enough by itself to support such an opinion.” Ruggiero, 424 F.3d at 254. Here, plaintiffs failed to explain below or on appeal how “the rigor of differential diagnosis performed, the expert’s training and experience, the type of illness or injury at issue, or some other case-specific circumstance” militates in favor of admitting that evidence to establish general causation. Id. Accordingly, the district court did not abuse its broad discretion in excluding differential-diagnosis evidence. Plaintiffs also argue that the district court improperly precluded them from obtaining other general-causation discovery. But the district court did not abuse its broad discretion in managing discovery. After the parties notified the district court of numerous discovery disputes, the court issued rulings from the bench ordering Bayer to produce millions of documents from more than fifty custodians. Forty-one of those custodians had been identified in the previous Mirena IUD MDL, but the court allowed plaintiffs to obtain documents from eleven new custodians. Despite plaintiffs’ arguments to the contrary, the district court considered relevance and proportionality when resolving the discovery disputes. We conclude that the district court’s thorough and well-reasoned discovery orders throughout the litigation were well within its wide discretion. CONCLUSION For the foregoing reasons, the district court’s judgment is AFFIRMED.
