Merck & Co. Inc. v. Garza

• Decision Date: 26 August 2011
• Docket Number: No. 09–0073.,09–0073.
• Citation: 347 S.W.3d 256,54 Tex. Sup. Ct. J. 1697
• Parties: MERCK & CO., INC., Petitioner,v.Felicia GARZA, et al., Respondents.
• Court: Texas Supreme Court

347 S.W.3d 256

54 Tex. Sup. Ct. J. 1697

MERCK & CO., INC., Petitioner,

v.Felicia GARZA, et al., Respondents.

No. 09–0073.

Supreme Court of Texas.

Argued Jan. 20, 2010.Decided Aug. 26, 2011.

Richard L. Josephson, Travis J. Sales, Stephen G. Tipps, Amy Pharr Hefley, Baker Botts, LLP, Houston, TX, Thomas R. Phillips, Baker Botts L.L.P., Austin, TX, Walter Dellinger, John H. Beisner, Charles C. Lifland, O'Melveny & Myers LLP, Washington DC, Baldemar Garza, The Law Office of Baldemar Garza, Rio Grande City, TX, Jaime A. Saenz, Rodriguez, Colvin Chaney & Saenz, L.L.P., Rene O. Oliveira, Roerig Oliveira & Fisher, Brownsville, TX, for Petitioner.David H. Hockema, Hockema & Longoria, Joe Escobedo Jr., Luis M. Cardenas, Escobedo, Tippit & Cardenas, L.L.P., Albert A. ‘Beto’ Munoz II, Law Office of Alberto A. Munoz, II, McAllen, TX, Cesar Ricardo Perez, Watts Law Firm, Edinburg, TX, Kathryn Snapka, The Snapka Law Firm, Corpus Christi, TX, Kevin H. Dubose, Alexander Dubose & Townsend LLP, Houston, TX, Alexandra Wilson Albright, University of Texas Law School, Douglas W. Alexander, Amy Warr, Alexander Dubose & Townsend LLP, Austin, TX, for Respondent.Justice HECHT delivered the opinion of the Court.

Respondents contend that Vioxx, a prescription drug, caused their decedent's death. In Merrell Dow Pharmaceuticals, Inc. v. Havner,¹ we set requirements for determining whether epidemiological evidence is scientifically reliable to prove causation. The parties here dispute what those requirements are, whether they apply in this case, and whether they were satisfied. We hold that Havner's requirements apply and were not met, and that the evidence was therefore legally insufficient to prove causation. Accordingly, we reverse the judgment of the court of appeals ² and render judgment that respondents take nothing.

I

A

Leonel Garza had a long history of heart disease. Twenty years before his death at age 71, he suffered a heart attack and four years later underwent quadruple bypass surgery to alleviate blockages in four of his coronary arteries. In the years that followed, he had one cardiac catheterization procedure that revealed additional blockages in three arteries, followed by a second such procedure that revealed severe recurrent coronary artery disease. He had a stent placed in his left main artery to increase the blood flow into his heart, but two years later was diagnosed with atherosclerotic obstructive disease and chronic venous insufficiency in his legs. He was also diagnosed with an abdominal aortic aneurysm.

Twenty-five days before his death, Garza complained to his cardiologist, Dr. Michael Evans, of intermittent numbness, pain, and weakness in his left arm. After determining that Garza was not having a heart attack, Evans ordered an ultrasound of Garza's neck to check the circulation to his brain and a stress test to check the circulation to his heart. Evans also gave him a week's supply of 25 mg Vioxx for pain relief and scheduled a follow-up visit eight days later.

When Garza returned for his appointment, Evans was out of town, and one of his partners, Dr. Juan Posada, reviewed Garza's test results with him and his wife. The stress test revealed that Garza had a stable cardiac status, and Posada noted in Garza's record that he thought Garza was on optimal medical management. However, the test did reveal some small areas of apical ischemia, meaning that a part of the tip of Garza's heart was not getting enough blood when stressed. Posada offered the possibility of a cardiac catheterization to more fully investigate the cause of the apical ischemia, but Garza declined, opting to discuss the results with Evans a month later. According to Mrs. Garza, Posada gave her husband thirty additional 25 mg Vioxx pills. Seventeen days later, on April 21, 2001, Garza died while alone at his ranch near Rio Grande City, Texas. The autopsy found that the immediate cause of death was a “probable myocardial infarction” initiated at least in part by the underlying cause of “severe coronary artery disease”.

Garza's statutory beneficiaries (“the Garzas”) sued Merck & Co., Inc., the manufacturer of Vioxx, for products liability, alleging that the drug was defective as designed and as marketed with inadequate warnings. Merck repeatedly challenged the scientific reliability of the Garzas' evidence offered to prove that Vioxx caused Garza's death. The trial court overruled Merck's objections. The jury returned a verdict for the Garzas, awarding $7 million actual damages, plus $25 million in punitive damages, which the trial court reduced to the applicable statutory maximum of $750,000.³ Merck appealed.

The court of appeals held that the Garzas could not recover on their design-defect claim because they did not present sufficient evidence of a safer alternative design, but that they could recover on their inadequate-warning claim.⁴ The court rejected Merck's argument that the Garzas had failed to meet Havner's requirements for proving causation because they had not produced two statistically significant epidemiological studies showing that Vioxx at the dose and for the duration taken by Garza more than doubles the risk of heart attack.⁵ The court believed that Havner did not “establish[ ] such a bright-line test for causation” but mandated that the sufficiency of the evidence be determined from its totality.⁶ An expert witness called by the Garzas testified that clinical trials had “indicated a more than two-fold risk of serious cardiovascular ‘adverse experiences' suffered by the people who participated in the studies ... within twelve weeks or less of taking Vioxx.” ⁷ The expert had opined that there was “a pretty strong case that the risk of Vioxx for heart attacks can occur at any time after the initiation of the medicine.” ⁸ The court concluded that this was sufficient evidence to support general causation. ⁹ However, the court reversed the Garzas's judgment for juror misconduct and remanded the case for a new trial.¹⁰

We granted Merck's petition for review complaining that judgment should be rendered against the Garzas.¹¹

B

Vioxx, or rofecoxib, is a non-steroidal anti-inflammatory drug (NSAID). NSAIDs block

the production of prostaglandins, which are hormone-like chemicals that are released in the body in response to injury. The prostaglandins cause inflammation, redness, swelling, pain, and fever. Reducing the amount of prostaglandins reduces inflammation and its symptoms. In order to inhibit production of prostaglandins, the NSAIDs act by blocking the enzyme cyclooxygenase (COX). After further study scientists discovered that the COX enzyme has two isoforms, one associated with inflammation (COX–II) and another thought to protect the lining of the stomach (COX–1).¹²

Early NSAIDs were non-selective, meaning that they restricted both forms of the COX enzyme, but Vioxx and the other selective NSAIDs only restrict COX–2.¹³ Scientists theorized that, by restricting only COX–2, a selective NSAID could provide the pain relief afforded by non-selective NSAIDs while avoiding their gastrointestinal complications, such as perforations, ulcers, and bleeding.¹⁴

After following Food and Drug Administration procedure for seeking approval of a new drug, Merck submitted its application in late 1998. A few months later, the FDA approved Vioxx as “safe and effective” for the treatment of osteoarthritis, acute pain, and menstrual pain. Merck then applied to the FDA for approval to use Vioxx to treat rheumatoid arthritis. As part of its application, Merck commissioned the VIGOR clinical trial, which was “designed to compare the occurrence of [gastrointestinal] toxicity with twenty-five and fifty milligrams per day of Vioxx or one thousand milligrams per day of Naproxen,” a non-selective NSAID.¹⁵ In addition to finding a gastrointestinal benefit, VIGOR also revealed a secondary finding that patients taking Vioxx had five times the relative risk of adverse cardiovascular events as patients who took Naproxen.¹⁶ But despite the fact that Merck employees had expressed concern since at least 1997 that Vioxx could present cardiovascular risks, Merck argued that the VIGOR results could be explained by a combination of chance and the cardio-protective effects of Naproxen.

Eventually, the FDA approved the use of Vioxx to treat rheumatoid arthritis, and after some negotiation, Merck placed the cardiovascular data from the VIGOR trial on the label for Vioxx, though not in the warnings section. In 2000, Merck again sought approval from the FDA for treatment of yet another condition, colon polyps. To test the efficacy of Vioxx in treating colon polyps Merck commissioned the APPROVe trial. But after APPROVe found that patients taking Vioxx had a statistically significant increased relative risk of adverse cardiovascular events compared to placebo after eighteen months of exposure, Merck announced that it would voluntarily remove Vioxx from the market on September 30, 2004. In 2005, the FDA commissioned an advisory panel to examine the cardiovascular concerns relating to Vioxx and other selective NSAIDs. The panel eventually concluded that the drugs did present cardiovascular risks after prolonged exposure, but it did not find that they presented a risk after only short-term use.

Thousands of lawsuits were filed across the country, alleging that Vioxx caused heart attacks or other adverse cardiovascular events. After a few cases were tried with mixed results, Merck agreed to pay $4.85 billion into a settlement fund for qualifying claims. The Garzas' claim did not qualify.

II

To prevail on their inadequate-warnings claim, the Garzas were required to prove that Garza's ingestion of Vioxx 25 mg pills over a period of 25 days was the producing cause of his heart attack. As we explained in Merrell Dow Pharmaceuticals, Inc. v. Havner,¹⁷ causation, in this context, has two components: general and specific. “General causation is whether a substance is...