The US Judicial Panel on Multidistrict Litigation expanded MDL 2691 Viagra (Sildenafil Citrate) Products Liability Litigation to include claims against Eli Lilly and Company, the manufacturer of Cialis, alleging that the erectile dysfunction drug causes melanoma, or skin cancer.
Both drugs work the same way by inhibiting an enzyme known as phosphodiesterase type 5, 1 or PDE5. Three studies link this action to increasing melanoma cells. Pfizer is the manufacturer of Viagra.
The MDL was created on April 7, 2016 and grew from 35 cases in May to 246 cases in December, 2016. US District Judge Richard Seeborg is supervising the MDL in the Northern District of California in San Francisco.
Pfizer knew of the risks
Among the plaintiff cases is Sue Matthews, Individually and as Personal Representative of the Estate of Robin Matthews v. Pfizer Inc., Case No.: 3:16-md-02691-RS. It charges that Pfizer knew of the significant risks of developing melanoma caused by Viagra, but the company did not adequately and sufficiently warn consumer or the medical community.
Robin Matthews of Virgin, Utah, took Viagra from 2005 to 2012. On Sept. 23, 2013 he went to urgent care for abdominal pain and doctors discovered melanoma lesions on his liver, kidneys, spleen, adrenal glands and lymph nodes. A MRI on Oct. 11, 2013 showed the cancer had spread to his bones and lungs. On Oct. 22 he died due to metastatic malignant melanoma.
The FDA approved Viagra on March 27, 1998. By 2012 doctors had written prescriptions for Viagra to more than 35 million men worldwide, producing worldwide revenue of $1.8 billion.
- A study published in 2011 found that treatment with Viagra can promote melanoma cell invasion. Specifically, by inhibiting PDE5, Viagra mimics an effect of gene activation and may potentially function as a trigger for the creation of melanoma cells.
- A 2012 study published in the Journal of Cell Biochemistry also found that PDE5 inhibitors were shown to promote melanin synthesis, which may exacerbate melanoma development.
- On April 7, 2014, an original study (“the JAMA study”) was published on the website for the Journal of the American Medical Association Internal Medicine which, in light of the earlier studies, sought to examine the direct relationship between sildenafil use and melanoma development in men in the United States. The JAMA study was published in the journal’s June 2014 edition. The study found that 25,848 participants who had recently used sildenafil exhibited an 84% increase in risk of developing or encouraging invasive melanoma.
“Despite these significant findings, Defendant has made no efforts in its ubiquitous Viagra advertisements to warn users about the potential risk of developing melanoma that has been scientifically linked to its drug,” the complaint alleges.