Monsanto aims to prohibit ‘unreliable’ plaintiffs’ experts in next Roundup test trial

Monsanto Co. is trying to change the landscape of evidence and testimony ahead of the next test trial over its Roundup weedkiller that plaintiffs allege causes cancer.

Expert witnesses for plaintiffs' attorneys representing more than 2,000 cancer-stricken people should be prohibited from testifying on theories that Roundup generally causes non-Hodgkin lymphoma and that the named plaintiff's cancer was specifically caused by exposure to the weedkiller, lawyers for the Bayer-AG owned company wrote in court documents filed Wednesday.

After three consecutive losses in federal and state court, the next test case is scheduled to start Feb. 24 before U.S. District Judge Vince Chhabria. Juries have all awarded additional damages after finding Monsanto suppressed unfavorable scientific findings.

Monsanto has maintained through three years of litigation that plaintiffs' attorneys are offering unreliable experts to testify on unfounded accusations Roundup exposure causes non-Hodgkin lymphoma. It has argued regulatory agencies around the world have consistently found over 40 years that Roundup's active ingredient, glyphosate, is not carcinogenic.

"In this case, plaintiffs' expert witnesses present speculation and self-selected bits of data, offer subjective opinions, and selectively parrot third party 'conclusions' in a transparent effort to side-step their obligations to demonstrate reliable methodologies of their own," defense attorney Joe G. Hollingsworth of Hollingsworth LLP in Washington, D.C. wrote in a 2017 court filing.

Plaintiffs' attorneys have said the International Agency for Research on Cancer, which found glyphosate as a probable human carcinogen in 2015, is the leading authority on the matter.

In addition to ghostwritten studies supporting the safety of Roundup, there has been some evidence presented to juries of Monsanto's attempts to influence the Environmental Protection Agency's findings on the matter. In one instance, Monsanto successfully convinced the EPA that repeating an unfavorable 1983 study finding mice exposed to glyphosate developed tumors was unnecessary.

The EPA reaffirmed in April glyphosate poses "no risks to public health" during an ongoing trial in Alameda County Superior Court. Defense attorneys sought to admit the development, but Judge Winifred Smith denied the request

The federal litigation consisted of 122 cases with 217 plaintiffs when Monsanto disclosed its seven expert witnesses in 2017. It has since grown to include roughly 2,000 lawsuits with more than 2,000 plaintiffs. Stevick v. Monsanto Co., 16-CV02341 (N.D. Cal., filed April 29, 2016).

Monsanto has also taken issue with the methodology, called a differential diagnosis, doctors have used to conclude the named plaintiffs' cancers were caused by Roundup exposure.

"Their experts have offered nothing more than say-so in dismissing other, well-recognized risk factors for plaintiffs' NHL, and in fact violate basic tenets of logic and scientific consistency in dismissing other causes based on reasoning that if faithfully employed would apply equally to Roundup," wrote defense attorney Brian Stekloff of Wilkinson Walsh Eskovitz in Washington, D.C.

Both sides agree non-Hodgkin lymphoma is a common cancer with no known cause in the majority of cases, but plaintiffs' attorneys have successfully argued that the Roundup exposure was so significant and prolonged it is the most likely cause.

Chhabria will consider the issue at a Jan. 29 hearing.