Monsanto Challenges Expert Testimonies in Roundup Lawsuits

On Thursday, Monsanto Co. filed multiple documents in the consolidated Northern District of California lawsuit purporting that the company is at fault for injuries caused by its herbicide, Roundup, specifically Non-Hodgkins lymphoma which is allegedly caused by continued exposure to Roundup. In the filings, Monsanto asked the court to rule that the testimonies of doctors cited in some of the individual cases should be excluded. 

In one of the filings, Monsanto claimed that the testimony of Dr. Dennis Weisenburger should be excluded because he considered “flawed studies that do not apply to the specific subtypes these Plaintiffs have and his failure to account for the fact that the majority of NHL cases have no known cause.” The motion also claimed that the doctor ignored other risk factors like welding. Monsanto purported that his opinions are unreliable and flawed, and said that they are more flawed than when the doctor’s opinion was considered previously in the consolidated case.  Weisenburger was cited as a “general and specific causation expert” by at least five of the plaintiffs. 

The motion said, “Dr. Weisenburger’s testimony in the Wave 2 cases confirms that he will always conclude that Roundup was a substantial cause of any plaintiff’s (Non-Hodgkin’s lymphoma), as long as they used Roundup for more than 2 days per year or more than 10 days in their lifetime. He does not seriously consider whether any plaintiff’s NHL could be idiopathic or could have been caused by other risk factors or other exposures. His treatment of potential alternative causes is thoroughly unscientific.” 

A separate motion filed by Monsanto asked the court to exclude the testimony of four other doctors. The motion acknowledged that the court previously denied Monsanto’s motion relating to these experts without prejudice, ruling that the challenges would be more appropriate in the plaintiff’s home districts after the cases are transferred. Monsanto, however, filed this motion to “expressly preserve() its right to file new motions” in the home districts. 

On Friday, another motion related to three additional experts, Drs. Barry Boyd, Lauren Pinter-Brown, and Ron Schiff, was filed by Monsanto. This document also claimed that they did not properly consider other causes of Non-Hodgkin’s Lymphoma when establishing a plaintiffs’ cause of illness. Monsanto argued in that motion that the experts did not rule out other causes of the disease, but instead pointed each time to Roundup. Similarly to the motion regarding Weisenburger, the company also claimed that the experts ruling Roundup as the cause was based on flawed studies. 

Monsanto asked for summary judgment in Monsanto’s favor in the cases where the plaintiffs had not submitted a reliable expert opinion supporting that Roundup was the cause of their illness. 

Another filing on Thursday by Monsanto addressed specific cases where the defendant alleged that the plaintiffs had not filed their claims within the required statute of limitations. On Friday, Monsanto also filed a motion for summary judgment relating to seven cases where it claimed “non-causation grounds,” specifically that the claims were preempted because the alleged risk of cancer from Roundup was reportedly not knowable at the time the products were sold. 

Monsanto is represented by Wilkinson Stekloff LLP, Hollingsworth LLP, Covington & Burling LLP, and Bryan Cave Leighton Paisner LLP