The Texas Supreme Court Hears Oral Argument in Merck & Co. v. Garza
The Texas Supreme Court heard oral argument on Wednesday of this past week in a case presenting important issues related to the use of clinical trial evidence to prove causation in prescription drug products liability cases. The case, Merck & Co. v. Garza, No. 09-0073, arose from the death of a 71-year-old heart patient, who suffered a fatal heart attack while allegedly taking a 30-day prescription of Vioxx for left arm pain relief. The San Antonio Court of Appeals affirmed a $7.5 million judgment, rejecting Merck’s arguments concerning the scientific reliability of plaintiffs’ expert opinion evidence that decedent’s short-term Vioxx use was a producing cause of his death but remanded the case for a new trial based on jury misconduct. Merck petitioned the supreme court for review.
Merck’s petition for review seeks to clarify certain issues arising under the 1997 opinion in Merrell Dow Pharmaceuticals, Inc. v. Havner, 953 S.W.2d 706. Specifically, Merck has asked the court to hold that its Havner causation requirements—that, as a matter of law, causation cannot be established with epidemiological studies unless plaintiff presents evidence of at least two statistically significant studies showing a greater-than-doubling of the risk at the same or lesser dose and duration as the plaintiff’s—constitute minimum requirements that must be satisfied in every case. Merck also has asked the court to hold that the Havner requirements apply not only to observational epidemiological studies, like those at issue in Havner, but also to clinical trials, which generally are more reliable. While Havner has been followed by a number of Texas courts in the 12 years since it was issued, it appears not yet to have been applied by a Texas state court in a case in which the epidemiological studies consisted of clinical trials.
Much of the oral argument focused on the two studies that plaintiffs contended satisfied Havner’s requirements. The first was a study of 2,434 patients at risk of a recurrence of colon cancer. The study was terminated prematurely in 2004 when concerns about cardiovascular events noticed in another study led Merck to withdraw Vioxx from the market. The study had not been published at the time of trial, but the court admitted in evidence an internal Merck email attaching “preliminary findings” of a statistically significant relative risk of 3.13. Among other things, the argument concerned whether such preliminary findings qualified as an epidemiological study under Havner. The second was an internal meta-analysis of a number of studies comparing Vioxx both with placebo and with other NSAIDs. An issue at argument was whether the results of the meta-analysis were inappropriately influenced by a “high dose” study.
Another focus of the argument was on Havner’s requirement that the plaintiff offer evidence excluding other plausible causes of the illness or injury with reasonable certainty. Plaintiffs argued that they had excluded decendent’s severe coronary artery disease, which the coroner indentified as the cause of his heart attack, with expert testimony that the autopsy had found fresh clots caused by Vioxx in two of the bypass arteries. Merck responded that the expert’s opinions were not supported with scientific evidence and, moreover, that its own expert, a pathologist who had examined the autopsy slides under high magnification, had determined that the occlusions observed by the coroner were not clots at all but rather hemorrhages within the arterial plaque, a condition that no one contends was caused by Vioxx.
The case was argued for Merck by Stephen Tipps, an appellate partner in the Houston office of Baker Botts L.L.P. A decision in the case is expected sometime in the early part of 2011.
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