A federal judge in Philadelphia dismissed more than 300 lawsuits against Pfizer Inc alleging that its antidepressant Zoloft caused birth defects in children born to women who took the drug while pregnant.

The decision late Tuesday from U.S. District Judge Cynthia Rufe in the Eastern District of Pennsylvania said that plaintiffs had not produced enough evidence to show a plausible scientific link between the drug and birth defects, following several previous decisions that excluded testimony from key expert witnesses for plaintiffs.

“The court recognizes that the final scientific verdict as to whether Zoloft can cause birth defects may not be delivered for many years,” Rufe wrote. “Nevertheless, plaintiffs chose when to file their cases, and the court concludes that for the plaintiffs who have continued to pursue their claims, the litigation gates must be closed.”

The ruling affects more than 300 lawsuits against Pfizer consolidated before Rufe in federal court.

A Pfizer spokeswoman, Neha Wadhwa, said the decision "affirms that plaintiffs have failed to produce any reliable scientific evidence demonstrating that Zoloft causes the injuries they alleged." 

Dianne Nast, a lead lawyer for the plaintiffs, did not immediately return a call for comment.

Pfizer had previously prevailed in two trials involving Zoloft birth-defect claims in state courts in Philadelphia and Missouri.

Zoloft is part of a widely prescribed group of antidepressants known as selective serotonin reuptake inhibitors, or SSRIs. Plaintiffs said that the company played down the birth-defect risks of the popular drug in order to boost sales, while Pfizer denied it acted improperly and said that a number of major medical groups, including the American Heart Association, have supported its position.