A Zofran pill, manufactured by GlaxoSmithKline Plc, is pictured in its packaging at a Walgreen's pharmacy in the Brooklyn borough of New York. Photo: Michael Nagle/Bloomberg News

A federal judge overseeing the multidistrict litigation alleging anti-nausea Zofran caused birth defects has indefinitely canceled the first bellwether trial this week due to the coronavirus.

The trial, originally scheduled for May 4, comes in a case brought by the parents of Maia Rodriguez, alleging their daughter was born in 2004 with heart defects due to her mother's use of Zofran during pregnancy. The trial would have been the first in more than 450 lawsuits filed against GlaxoSmithKline.

Plaintiffs attorney Kimberly Barone Baden, of Motley Rice, did not respond to a request for comment. Baden is on a plaintiffs team that also includes Robert Jenner of Jenner Law in Baltimore; Tobias Millrood of Pogust Millrood in Conshohocken, Pennsylvania; Elizabeth Graham of Grant & Eisenhofer in Wilmington, Delaware; and James Gotz, a Boston partner at Hausfeld.

GlaxoSmithKline's attorneys, Jennifer Hill at Shook, Hardy & Bacon in Kansas City, Missouri, and Lisa Blatt of Washington, D.C.'s Williams & Connolly, did not respond to a request for comment. A GSK representative declined to comment.

On Tuesday, U.S. District Judge Dennis Saylor of the District of Massachusetts, in Boston, ordered the trial canceled, as well as an April 30 pretrial conference. He did not set a new date.

In 2012, GSK agreed to pay $3 billion to settle a Justice Department civil and criminal investigation involving its "off-label" marketing of pharmaceutical drugs including Zofran. The lawsuits allege that Zofran, which the U.S. Food and Drug Administration approved in 1991 for the treatment of nausea and vomiting related to chemotherapy and surgery, has resulted in heart defects, cleft lip and cleft palate in babies born to women who took the prescription medication. The cases, citing various clinical studies mostly on animals, allege that GSK failed to warn doctors of the side effects of the drug when used in women to treat morning sickness in the first trimester of pregnancy.

Last year, Saylor postponed the same trial, then scheduled for Sept. 16, following the U.S. Supreme Court's 2019 decision on federal preemption in Merck Sharp & Dohme v. Albrecht, which found the pharmaceutical manufacturer could not provide "clear evidence" that the U.S. Food and Drug Administration would have rejected a change to the warning labels on its osteoporosis drug Fosamax. The ruling also found that a judge, not a jury, should decide whether "clear evidence" existed.

Last month, plaintiffs attorneys brought a motion for sanctions to strike GSK's renewed preemption defense, following Merck, based on its "inexcusable and sanctionable discovery misconduct" in lobbying the FDA over a pending citizen petition. Saylor rejected that motion, which GSK called untrue "conspiracy theories."