
Pfizer and Eli Lilly defeat lawsuit over claims Viagra and Cialis cause cancer
pharmafile | April 9, 2020 | News story | Business Services | Pfizer, viagra
Pfizer and Eli Lilly have defeated a class action lawsuit seeking billions in damages over claims that Viagra and Cialis cause skin cancer.
More than 1,000 lawsuits were consolidated into a multidistrict case heard in San Fransisco. US District Judge Richard Seeborg issued a judgment in favour of the drug makers. In his ruling on Wednesday, he wrote that the companies are “are entitled to and hereby are granted summary judgment in their favour as to all of plaintiffs’ claims.”
In October, Seeborg had heard testimony from experts on whether the ingredients found in Viagra and Cialis cause cancer. However, he found problems with this testimony.
The judge found that the three main experts failed to apply a Bradford Hill analysis to their findings, which requires nine factors to determine causation that include: strength of the association; consistency; specificity; temporality; biological gradient or dose response; biological plausibility; coherence with other scientific knowledge; experimental evidence and analogy.
Seeborg found that the evidence provided either did not support a strong association or relied on smaller studies, as most historic studies on this issue did no show a link between erectile dysfunction drugs and skin cancer. He wrote that: “Despite substantial research on the issue over many years, plaintiffs’ experts apparently stand alone.”
On 13 January, he limited what evidence that could be brought to trial and in that ruling he rejected the casual link between the erectile dysfunction drugs and melanoma.
Pfizer’s Viagra was approved in 1998 and went on to make the company tens of billions of dollars, but lost its exclusive rights in December 2017 and generics are now available. Eli Lilly’s Cialis was approved to in 2003, and maintained the exclusive rights until 2017.
Conor Kavanagh
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