A class action lawsuit has been filed in the United States against Pfizer, alleging that the pharmaceutical giant failed to warn women about the risk of brain tumours associated with its contraceptive injection, Depo-Provera. The lawsuit, brought on behalf of women who developed intracranial meningiomas, claims that using the quarterly injection for more than a year significantly increases the risk of these tumours.
The number of lawsuits has tripled since May to over 1,300, consolidated in multi-district litigation in Pensacola, Florida, where a hearing is scheduled for Monday. The potential claim value could reach several billion dollars, with expectations that the number of cases could rise to between 5,000 and 10,000.
A study published in the British Medical Journal in March 2024 found that prolonged use of medroxyprogesterone acetate, the active ingredient in Depo-Provera, was linked to a 5.6-fold higher risk of intracranial meningioma. These benign tumours grow slowly but can cause vision or hearing loss, headaches, and seizures, often requiring surgical removal.
Pfizer argues that it attempted to add a tumour warning to the drug's label but was rejected by the US Food and Drug Administration (FDA). The company claims this is a clear case of pre-emption, where federal law bars state liability claims. However, plaintiffs contend that Pfizer's request was too broad, grouping Depo-Provera with lower-dose contraceptives, leading to the FDA's decision.
Virginia Buchanan, a partner at Levin Papantonio representing the plaintiffs, stated: 'Pfizer is attempting to avoid accountability by invoking a pre-emption defence, yet there are serious questions about whether it ever provided the FDA with the full picture.' The hearing will focus on five pilot cases to test Pfizer's pre-emption defence.
Depo-Provera has been marketed in the UK since the 1980s and is used by 15% of women in the country. Pfizer has updated label warnings in Canada and Europe, and the UK label was updated last year. The US law firm Berger Montague is also investigating potential shareholder legal action against Pfizer's board.
