GSK has agreed to pay up to $2.2 billion to settle most lawsuits in U.S. state courts claiming that a discontinued version of the heartburn drug Zantac caused cancer, the company announced on Wednesday.

UK-based pharmaceutical giant GSK, or GlaxoSmithKline, has announced that it has agreed to settle nearly 80,000 state-level Zantac cases. The lawsuits claimed that the now-discontinued version of the heartburn drug caused cancer,

The settlement, which is at the low end of Jefferies analysts’ $2 billion to $3.5 billion estimate, will resolve 93% of the product liability cases regarding allegations that GSK’s heartburn drug could cause cancer.

GSK Plc shares surged after the UK pharma company agreed to pay as much as $2.2 billion to resolve about 80,000 US court cases alleging that its old reflux medication Zantac was contaminated with a suspected carcinogen.

GSK has agreed to pay up to $2.2 billion to settle most pending U.S. state court lawsuits claiming that a discontinued version of the heartburn drug Zantac caused cancer, the company announced on Wednesday.

GSK has agreed to pay $2.2 billion to settle most of the pending lawsuits that claimed a discontinued version of the Zantac heartburn medication caused cancer.

GSK said it expects to take a charge of £1.8 billion ($2.3 billion) in its third-quarter results in relation to the settlements, which will be funded through "existing resources," and said there will be "no changes to GSK's growth agenda or investment plans for R&D as a result."

GSK shares jumped as much as 6.5% on Thursday after the British drugmaker struck a $2.2 billion settlement over U.S. lawsuits that alleged its discontinued heartburn drug Zantac caused cancer.

GSK shares in London jumped 5% Thursday after the British drug giant said it has resolved most of the U.S. lawsuits it faced around claims that its discontinued heartburn medicine Zantac causes cancer.