A Pfizer Inc. report shows a scientist warned executives last year about a potential link between the anti-depressant drug Zoloft and birth defects and recommended changes to the medication’s safety warning.
The document from a Pfizer drug-safety official might complicate the company’s efforts to fend off lawsuits brought by parents of children with malformed hearts. Pfizer has consistently rejected suggestions Zoloft caused newborn abnormalities and said Monday the document was taken out of context by lawyers suing the company.
Pfizer faces more than 1,000 suits alleging the company sold Zoloft, once the U.S.’s most-prescribed anti-depressant, knowing it could cause cardiac abnormalities in newborns. The company successfully defended in the first lawsuit to go to trial in April, before the disclosure of the document last week in a Philadelphia case.
“I don’t see how they could go before a jury with a straight face and make that argument now that these documents have surfaced,” said Jim Morris, a Los Angeles-based lawyer who had tried product-liability cases against Pfizer in the past. Morris hasn’t sued the drugmaker over Zoloft.
“A jury could easily find it to be a bald-faced lie to say there’s no credible ties between Zoloft and birth defects when your own people are citing studies and adverse-event reports highlighting the links,” Morris said.
Pfizer researchers also acknowledged in a 1998 report, which has been introduced into evidence in the Philadelphia trial, they’d found more than a dozen side-effect reports about babies’ birth defects for which their mothers’ Zoloft use couldn’t be ruled out as a cause.
Pfizer said the internal reports summarizing the Zoloft studies and the review of side-effect reports were mischaracterized by the plaintiff’s lawyers.
“Plaintiffs also have cherry-picked data from Pfizer’s review of adverse event reports and ignored the conclusions of these reports that contradict their testimony,” Christine Regan Lindenboom, a Pfizer spokeswoman, said in an e-mailed statement.
Recent filings with U.S. and European health regulators support the company’s contention that no credible link has been found between the drug and birth defects, Lindenboom said.
Pfizer seeks to persuade the Philadelphia jury to reject Mia Robinson’s claims blaming her cardiac defects, including a hole in her heart, on her bipolar mother’s use of Zoloft.
In the April case, a state-court jury in St. Louis sided with Pfizer and rejected arguments Zoloft caused defects that required a boy to undergo three open-heart surgeries and have a pacemaker implanted.
Francesca Kolitsopoulous, who was the associate director in Pfizer’s Worldwide Safety Strategy unit’s epidemiology group, said in an internal company report she reviewed published studies that showed an association between the medicine and “cardiac malformations, which could be causal.”
Her April 2014 review concluded researchers found links between Zoloft and septal heart defects, a congenital disorder that features a hole in a baby’s heart. The researchers also found ties between the anti-depressant and omphalocele, a birth defect of the abdominal wall, with intestines or organs forming outside the belly.
After reviewing the Zoloft studies, Kolitsopoulous proposed modifying the drug’s warning label to add findings of some researchers who’d identified potential links between the drugs and birth defects, the report shows.
“While the risks may appear to be increased for specific birth defects, these defects are rare and the absolute risks small,” she said.
Sixteen years earlier, Pfizer safety monitors reviewed 50 Zoloft side-effect reports from pregnant women who’d taken the drug, according to evidence made public for the first time in Robinson’s case.
They found 25 cases involving “congenital abnormalities” or other “adverse events” were considered to be “possibly related” to Zoloft use, according to the October 1998 report. It was the first time the file has been made public.
When researchers dug deeper, they found in 16 of the cases, “there was no obvious cause” for the defect other than the mother’s use of the anti-depressant, the review of side-effect reports shows.
New York-based Pfizer pulled in about $3.3 billion in Zoloft sales in 2005, making it the best-selling antidepressant on the market.
Robinson’s family is seeking at least $2.4 million in damages to cover her future medical expenses.
The allegations against Zoloft mirror claims against GlaxoSmithKline Plc over its Paxil antidepressant. The London-based drugmaker agreed in 2010 to pay more than $1 billion to settle more than 800 suits accusing the drugmaker of ignoring birth-defect risks. Glaxo also paid another $3 billion to resolve a government probe of claims it illegally promoted prescription drugs, including Paxil.
The Zoloft case is Robinson v. Wolters Kluwer Health Inc., July Term, 2011, No. 778, Control No. 14123047, Pennsylvania Court of Common Pleas of Philadelphia County (Philadelphia).