A panel of the 3rd U.S. Circuit Court of Appeals in Philadelphia upheld the April 2016 dismissal of the cases by a lower court judge, who said the plaintiffs had not shown a plausible scientific link between Zoloft and the birth defects.
The panel said the judge properly excluded testimony from Nicholas Jewell, a professor at the University of California at Berkeley who the plaintiffs wanted to call as an expert witness to establish the link, because it was not sufficiently reliable.
"Courts are supposed to ensure that the testimony given to the jury is reliable and will be more informative than confusing," Circuit Judge Jane Roth wrote for the three-judge panel. "Dr. Jewell's application of his purported methods does not satisfy this standard."
Lawyers for the plaintiffs did not immediately respond to requests for comment. Pfizer had no immediate comment.
Zoloft is part of a popular group of antidepressants known as selective serotonin reuptake inhibitors, or SSRIs.
The plaintiffs accused Pfizer of downplaying Zoloft's risks to boost sales.