GSK PLC (LSE:GSK, NYSE:GSK) and other pharmaceutical companies asked a Delaware court to allow an appeal of a ruling permitting over 70,000 lawsuits claiming Zantac causes cancer.
Analysts had expected the UK drug giant, along with Pfizer, Sanofi and Boehringer Ingelheim to contest the original ruling.
Judge Vivian Medinilla of Delaware Superior Court will decide if the appeal can go directly to the Delaware Supreme Court. If denied, the companies will request the Supreme Court to hear the case.
The companies argue Medinilla should have blocked plaintiffs from presenting expert testimony linking Zantac to cancer, which would have ended most lawsuits in Delaware.
Separately, GSK announced that a woman dropped her Zantac-related breast cancer case before trial.
In opening deals, stock in the pharma group was up just under 1% at 1,633p.