Inhibitors selective for prostaglandin G/H synthase-2 (PGHS-2) (known colloquially as COX-2) were designed to minimize gastrointestinal complications of traditional NSAIDs--adverse effects attributed to suppression of COX-1-derived PGE2 and prostacyclin (PGI2). Evidence from 2 randomized controlled-outcome trials (RCTs) of 2 structurally distinct selective inhibitors of COX-2 supports this hypothesis. However, 5 RCTs of 3 structurally distinct inhibitors also indicate that such compounds elevate the risk of myocardial infarction and stroke. The clinical information is biologically plausible, as it is compatible with evidence that inhibition of COX-2-derived PGI2 removes a protective constraint on thrombogenesis, hypertension, and atherogenesis in vivo. However, the concept of simply tipping a "balance" between COX-2-derived PGI2 and COX-1-derived platelet thromboxane is misplaced. Among the questions that remain to be addressed are the following: (a) whether this hazard extends to all or some of the traditional NSAIDs; (b) whether adjuvant therapies, such as low-dose aspirin, will mitigate the hazard and if so, at what cost; (c) whether COX-2 inhibitors result in cardiovascular risk transformation during chronic dosing; and (d) how we might identify individuals most likely to benefit or suffer from such drugs in the future.

/pdf/biological-basis-for-the-cardiovascular-consequences-of-cox-15c4o40mh2.pdf

Biological basis for the cardiovascular consequences of COX-2 inhibition: therapeutic challenges and opportunities

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(04)16893-1.pdf

Comparison of lumiracoxib with naproxen and ibuprofen in the Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET), reduction in ulcer complications: randomised controlled trial.

Gastrointestinal toxicity of nonsteroidal antiinflammatory drugs

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(04)16894-3.pdf

Comparison of lumiracoxib with naproxen and ibuprofen in the Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET), cardiovascular outcomes: randomised controlled trial.

Background: Evidence suggests that both selective cyclooxygenase (COX)-2 inhibitors and non-selective non-steroidal anti-inflammatory drugs (NSAIDs) increase the risk of cardiovascular events. However, evidence from prospective studies of currently available COX-2 inhibitors and non-selective NSAIDs is lacking in patients at high cardiovascular risk who are taking aspirin. Objective: To determine the cardiovascular outcomes in high risk patients with osteoarthritis treated with ibuprofen, naproxen or lumiracoxib. Methods: The Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET) of 18 325 patients with osteoarthritis comprised two parallel substudies, comparing lumiracoxib (COX-2 inhibitor) with either ibuprofen or naproxen. A post hoc analysis by baseline cardiovascular risk, treatment assignment, and low-dose aspirin use was performed. The primary composite end point was cardiovascular mortality, non-fatal myocardial infarction, and stroke at 1 year; a secondary end point was the development of congestive heart failure (CHF). Results: In high risk patients among aspirin users, patients in the ibuprofen substudy had more primary events with ibuprofen than lumiracoxib (2.14% vs 0.25%, p = 0.038), whereas in the naproxen substudy rates were similar for naproxen and lumiracoxib (1.58% vs 1.48%, p = 0.899). High risk patients not taking aspirin had fewer primary events with naproxen than with lumiracoxib (0% vs 1.57%, p = 0.027), but not for ibuprofen versus lumiracoxib (0.92% vs 0.80%, p = 0.920). Overall, CHF developed more often with ibuprofen than lumiracoxib (1.28% vs 0.14%; p = 0.031), whereas no difference existed between naproxen and lumiracoxib. Conclusions: These data suggest that ibuprofen may confer an increased risk of thrombotic and CHF events relative to lumiracoxib among aspirin users at high cardiovascular risk. The study indicates that naproxen may be associated with lower risk relative to lumiracoxib among non-aspirin users. This study is subject to inherent limitations, and therefore should be interpreted as a hypothesis-generating study.

/pdf/cardiovascular-outcomes-in-high-risk-patients-with-5sdqemxeij.pdf

Cardiovascular outcomes in high risk patients with osteoarthritis treated with ibuprofen, naproxen or lumiracoxib

Summary


Background : Cyclooxygenase-2 selective inhibitors were developed in order to reduce the incidence of life-threatening gastrointestinal ulcer complications compared with non-selective non-steroidal anti-inflammatory drugs. Previous outcomes studies have, variously, lacked power to investigate this endpoint, focused on broader outcomes, or been too small to quantify the influence of aspirin.



Aim : To evaluate lumiracoxib, a novel cyclooxygenase-2 selective inhibitor, vs. non-selective non-steroidal anti-inflammatory drugs in an outcomes study of considerably increased size. This paper describes the study's methodology.



Methods and patients : The Therapeutic Arthritis Research and Gastrointestinal Event Trial was a randomized, double-blind, 52-week study of lumiracoxib 400 mg once daily (two to four times the recommended dose for osteoarthritis) versus naproxen 500 mg twice daily or ibuprofen 800 mg three-times daily in patients with osteoarthritis. Randomization was stratified for low-dose aspirin use and age (≤ 64, 65–74, ≥ 75 years). The study was powered to investigate upper gastrointestinal ulcer complications (primary endpoint) in patients not taking aspirin and in the overall study population; other endpoints included cardiovascular, renal and hepatic measures.



Conclusions : Therapeutic Arthritis Research and Gastrointestinal Event Trial was designed to provide definitive answers concerning the gastrointestinal safety of lumiracoxib, addressing the controversial issues arising from outcomes studies with other cyclooxygenase-2 selective inhibitors.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2036.2004.02026.x

J. Huels

Papers

Therapeutic arthritis research and gastrointestinal event trial of lumiracoxib - study design and patient demographics.