Plaintiff alleged that his use of the antacid medication Zantac caused him to develop prostate cancer because Zantac’s active ingredient, ranitidine, has been found to degrade N-nitrosodimethylamine (“NDMA”).
Brand Defendants’ filed a motion to exclude Plaintiff’s expert Dr. Steven Bird under Daubert.
Pharmacy Expert Witness
Steven Bird is a lead epidemiologist at the Food and Drug Administration / Center for Drug Evaluation and Research. He is responsible for the science and administration function of the team and to ensure that reviewers provide quality review and consultation to review divisions within established timeframes.
Discussion by the Court
Bird opined that (1) NDMA is a potent carcinogen; and (2) Plaintiff’s exposure to NDMA from Zantac (generic name ranitidine) use was a substantial causative factor for his prostate cancer.
Bird (1) performed a “differential etiology methodology” where he purports to “rule in” ranitidine as a potential cause of Plaintiff’s prostate cancer and to “rule out” other causes, and (2) calculates Plaintiff’s lifetime exposure to NDMA from ranitidine by averaging the NDMA levels from other Plaintiffs’ expired ranitidine tablets and then converting his results to inhaled exposure risk estimates from a study of occupational NDMA exposure in rubber workers. The Brand Defendants argued that Bird’s opinions do not pass muster under Daubert based on his unreliable application of his chosen methodology to reach his specific causation opinion and his use of novel extrapolations to calculate Plaintiff’s NDMA exposure.
Bird’s application of the differential etiology methodology is unreliable because he unreliably “rules in” ranitidine use as a potential cause of Plaintiff’s cancer
Bird rejected all published, peer-reviewed ranitidine epidemiological studies assessing whether ranitidine is associated with prostate cancer—Rossing (2000), Habel (2000), Yoon (2021), Kantor (2021), Wang (2022), and You (2023)—none of which shows a statistically significant increased risk. Bird instead relied on the unpublished, non-peer-reviewed Braunstein manuscript, which examined only a cross-sectional, moment-in-time “snapshot” of cancer patients from Braunstein’s hospital. The Court held that Bird’s methodology of rejecting the published, peer-reviewed ranitidine epidemiology while embracing the unpublished Braunstein study is not reliable or based on scientific principles, and renders his opinion that ranitidine can cause prostate cancer unreliable.
Bird does not reliably “rule out” other potential causes
In terms of ruling out potential causes, Bird conceded he made no attempt to “rule out” Plaintiff’s other risk factors for prostate cancer, in particular Plaintiff’s significant family history of cancer.
The Court accordingly finds that Bird’s failure to do so renders his application of the differential etiology methodology unreliable, and warrants its exclusion.
Bird’s extrapolations from expired ranitidine pills and the Hidajat study are the type of guesswork against which Daubert is meant to shield
Bird purported to calculate (1) Plaintiff’s lifetime NDMA exposure from ranitidine use, and (2) the average and per quartile total NDMA exposure of rubber factory workers in the Hidajat study. Bird then uses these calculations to place Plaintiff within the cancer risk quartiles in the Hidajat study to estimate Plaintiff’s total prostate cancer risk from NDMA exposure.
Using this extrapolation methodology, Bird concluded Plaintiff’s NDMA exposure from ranitidine significantly increased his risk of prostate cancer.
Bird opined that Plaintiff absorbed as much NDMA through his use of ranitidine as the rubber workers in Hidajat’s “Quartile IV” had absorbed in their years of working in UK rubber factories. The Court held that the steps Bird had taken to reach this opinion are not a part of any reliable methodology, let alone a reliable application of any methodology. Indeed, the Zantac MDL Court found that “the number of assumptions and estimations necessary to render the Hidajat study helpful to” an expert’s general causation opinion about ranitidine use was “staggering.”
Held
The Court granted Brand Defendants’ motion to exclude Plaintiff’s expert Steven Bird.
Key Takeaway:
Bird’s methodology of rejecting the published, peer-reviewed ranitidine epidemiology while embracing the unpublished Braunstein study is not reliable or based on scientific principles. Moreover, Bird conceded he made no attempt to “rule out” Plaintiff’s other risk factors for prostate cancer, in particular Plaintiff’s significant family history of cancer. When Bird concluded Plaintiff’s NDMA exposure from ranitidine significantly increased his risk of prostate cancer, the Court held that the steps Bird had taken to reach this opinion are not a part of any reliable methodology, let alone a reliable application of any methodology.
Case Details:
| Case Caption: | Wilson V. Boehringer Ingelheim Pharmaceuticals, Inc. Et Al |
| Docket Number: | 22CA000284 |
| Court: | Circuit Court of the Thirteenth Judicial Circuit of Florida, Hillsborough County |
| Order Date: | August 15, 2024 |
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