In re Zoloft (Sertralinehydrochloride) Products Liability Litigation
176 F. Supp. 3d 483
E.D. Pa.2016Background
- This MDL consolidated cases alleging that maternal use of Zoloft (sertraline) during pregnancy causes birth defects; the Court held extensive discovery and multiple Daubert hearings on general causation.
- Plaintiffs initially offered epidemiologist Dr. Anick Bérard and three biological/mechanistic experts; the Court excluded Dr. Bérard and limited or excluded the others as to human causation.
- The PSC sought leave to add statistician Nicholas Jewell; the Court granted leave but later excluded Dr. Jewell after an extended hearing for methodological flaws.
- Plaintiffs subsequently submitted and then withdrew supplemental reports by Drs. Levin and Sadler; they later attempted to use those and new expert declarations (including Dr. Abdulla and former FDA Commissioner Kessler) in opposition to summary judgment.
- Pfizer moved for summary judgment after exclusion of the plaintiffs’ epidemiology/statistics experts; the Court reviewed the evidentiary record (expert reports, adverse-event case reports, internal Pfizer documents) and applied Daubert and summary-judgment standards.
- The Court concluded plaintiffs lacked admissible expert proof of general causation (that Zoloft is capable of causing the alleged birth defects in humans) and granted summary judgment for defendants, denying dismissal without prejudice.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether plaintiffs produced admissible evidence establishing general causation (Zoloft can cause birth defects in humans) | Epidemiology not strictly required; biological plausibility, adverse event reports, internal Pfizer documents, differential diagnoses, and experts (Kessler, Abdulla) create triable issue | Plaintiffs failed to produce any admissible expert who reliably reconciled the full epidemiological record; excluded experts leave no reliable general-causation proof | Held for Defendants: no admissible expert evidence of general causation; summary judgment granted |
| Admissibility of new or supplemental expert opinions after Daubert rulings (Drs. Levin, Sadler, Jewell) | Plaintiffs sought to resurrect or supplement previously excluded opinions and introduce new declarations specific to trial-ready cases | Defendants argued prior exclusions and scheduling orders bar reintroduction; methodologies were unreliable | Court enforced prior Daubert rulings: excluded testimony not previously admitted and rejected attempts to circumvent exclusions |
| Use of differential diagnosis / specific-causation opinions to establish general causation | Differential diagnoses by pediatric cardiologist (Dr. Abdulla) could support both general and specific causation on a case-by-case basis | Differential diagnosis cannot substitute for general-causation proof; Abdulla assumed general causation and did not reliably "rule in" Zoloft | Court held differential diagnosis here insufficient to prove general causation and inadmissible to fill that gap |
| Whether dismissal without prejudice is appropriate if summary judgment is granted | Plaintiffs requested dismissal without prejudice to preserve future claims if science advances | Defendants argued the MDL involved exhaustive litigation, expense, and plaintiffs had multiple chances to present admissible proof; permitting dismissal would be unfair | Court denied dismissal without prejudice as inequitable given extensive prior proceedings and repeated opportunities to prove general causation |
Key Cases Cited
- Daubert v. Merrell Dow Pharm., 509 U.S. 579 (1993) (establishes federal admissibility standard for expert testimony)
- General Elec. Co. v. Joiner, 522 U.S. 136 (1997) (district court may exclude expert opinion that lacks sufficient fit between data and conclusion)
- Anderson v. Liberty Lobby, 477 U.S. 242 (1986) (standard for summary judgment and when a jury could find for nonmoving party)
- Celotex Corp. v. Catrett, 477 U.S. 317 (1986) (summary-judgment burdens of movant and nonmovant)
- Heller v. Shaw Indus., 167 F.3d 146 (3d Cir. 1999) (medical experts need not always cite published epidemiology, but existing epidemiology cannot be ignored)
- In re Diet Drugs (Phentermine/Fenfluramine/Dexfenfluramine) Prods. Liab. Litig., 890 F. Supp. 2d 552 (E.D. Pa. 2012) (discusses acceptable bases for causation opinions and differential diagnosis)
- In re Paoli R.R. Yard PCB Litig., 35 F.3d 717 (3d Cir. 1994) (factors relevant to dismissal without prejudice in mass toxic-tort litigation)