Niacin, in combination with laropiprant, appears to provide no benefit and may have harmful effects in patients with vascular disease, researchers reported.

The 4-year HPS2-THRIVE study tested a combination of extended-release niacin 2 g plus laropiprant 40 mg (Tredaptive, Merck) compared with placebo in 25,673 patients at risk for CV events. In addition, all patients received simvastatin (Zocor, Merck), with or without ezetimibe (Zetia, Merck).

According to results presented at a late-breaking clinical trials session, the study did not meet the primary endpoint of reducing risk for a major vascular event, defined as a composite of nonfatal MI or CV-related death, stroke, or need for angioplasty or bypass surgery. Patients assigned extended-release niacin/laropiprant had a similar number of major vascular events compared with patients assigned placebo (13.2% vs. 13.7%; P=.29).

The extended-release niacin/laropiprant had increased rates of excess bleeding (2.5% vs. 1.9%) and infections (8% vs. 6.6%). In addition, serious adverse events were more prevalent with combination therapy, including new-onset diabetes (9.1% vs. 7.3%), diabetic complications (11.1% vs. 7.5%), indigestion and diarrhea (4.8% vs. 3.8%) and rashes (0.7% vs. 0.4%).

Data by the HPS2-THRIVE Collaborative Group published in European Heart Journal in early March revealed that by the end of the study 25% of patients assigned combination therapy had stopped treatment compared with 17% of patients assigned placebo.

“A striking finding from the study was a significant excess [in adverse events] among people who were allocated the niacin preparation. The excess represents a 3% absolute excess, which means 30 patients for every 1,000 treated patients had at least one side effect,” Jane Armitage, FFPH, FRCP,professor at the University of Oxford, United Kingdom, said at a press conference.

“It was a disappointing result but, nevertheless, these are clear and reliable results from a large study.”

PERSPECTIVE

Christie M. Ballantyne

• We confirmed that using niacin in well-treated patients on statins with low LDL does not have a benefit. That was a very common use for this medicine. The other important point this study nails down is that the adverse effects of niacin in extended release were considerable. If we are going to use the drug in patients with high LDL, we have to think about the modest benefits and risks.
• Christie M. Ballantyne, MD
• Professor of Medicine
  Baylor College of Medicine
  • Source: Endocrine Today.