A California jury that awarded a $289 million Roundup verdict disregarded science and the consensus of federal regulators and fell victim to "emotional manipulation," according to the state's doctors, farmers and biotech firm Genentech Inc., in amicus briefs filed in Monsanto's appeal.

In three separate briefs, the California Farm Bureau Federation, the Civil Justice Association of California and Genentech sought to reverse the 2018 verdict against Monsanto, now owned by Bayer.

In a combined brief, the California Medical Association, the California Hospitals Association and the California Dental Association took no position on whether to toss the verdict. Instead, they cautioned, "the answer to complex scientific questions such as that which the jury was required to resolve in this case should be based on accepted scientific evidence and rigorous scientific reasoning, not speculation and emotion."

"Here, the relevant scientific literature, scientific investigators, and government agencies were on trial," wrote Curtis Cole, of San Marino, California's Cole Pedroza, in the Aug. 30 brief. "Worse, the jury's answer was based on their policy choices, not on scientific consensus. Worst of all, the jury's analysis of risk and benefit was subject to emotional manipulation."

Monsanto, hit by three verdicts in California, faces more than 18,000 lawsuits alleging Roundup ingredient glyphosate caused non-Hodgkin lymphoma. In the second verdict, a federal jury in San Francisco awarded $80 million on March 27.  On May 13, a jury in Alameda County Superior Court awarded $2 billion to a California couple who each got non-Hodgkin lymphoma.  Judges in both cases have reduced the verdicts, which Monsanto has appealed.

San Francisco Superior Court Judge Suzanne Bolanos also reduced the $289 million verdict to $78 million, which included punitive damages.

The amicus briefs latched onto a portion of Monsanto's appeal that challenged the jury's imposition of punitive damages and the plaintiffs' evidence of causation—that is, whether glyphosate caused Dewayne Johnson, a school groundskeeper, to get non-Hodgkin lymphoma at age 43. Monsanto also noted that Bolanos had refused its request to introduce evidence from the U.S. Environmental Protection Agency finding glyphosate to be safe.

Plaintiffs attorneys, in their appeal, defended the jury's finding and their science, which included a 2015 decision by the International Agency on the Research for Cancer, part of the World Health Organization, that glyphosate was a possible carcinogen.

Amicus groups drew comparisons of the scientific evidence in the Roundup verdicts to that in cases alleging injuries associated with silicone breast implants or vaccines, which turned out to be wrong.

The California health care groups, in their amicus brief, called the jury's finding in the first Roundup trial "suspicious." Cole, their attorney, wrote that the plaintiffs' causation expert speculated about what caused Johnson's cancer.

"Such medical testimony invites the jury to speculate," he wrote. "In this case, there is reason to suspect the jury's decision also may have been based on emotion, rather than reason."

Jurors, Cole wrote, should not be deciding a "complex scientific question" by acting as "policymakers."

Genentech, along with the California Farm Bureau and CJAC, in briefs filed on Tuesday, said juries should not award punitive damages against a company that followed federal regulations, as Monsanto did.

"This case provides the court with an opportunity to ensure that verdicts in California are based on sound science," wrote Laura Brill, of Kendall Brill & Kelly in Los Angeles, in Genetech's Aug. 30 amicus brief. "The court should act on that opportunity."