Four cancer patients in the hometown of its agricultural subsidiary Monsanto are scheduled to make their case beginning on Friday (January 24).

The lawsuit marks the first multi-plaintiff trial in the litigation over whether glyphosate, Roundup's active ingredient, is carcinogenic.

It is being held in St. Louis, where the Monsanto unit was headquartered before Bayer bought the company in a $63 billion deal in 2018.

Roundup cancer lawsuits against Bayer in the United States have ballooned to more than 75,000 since the company was hit with multibillion-dollar verdicts, as three consecutive juries found the company liable for causing cancer.

Bayer is appealing those verdicts.

The company denies all allegations that Roundup or glyphosate causes cancer, saying decades of independent studies have shown the world's most widely used weed killer to be safe for human use...

and noting that regulators around the world have approved the product.

Bayer's share price has tumbled since the first verdict in August 2018.

And the company is currently negotiating with lawyers to settle the entire litigation.