Merck & Co is to launch its combination cholesterol drug Tredaptive, which was rejected by US regulators a year ago, in a number of key international markets by the third quarter.

The company says that Tredaptive (extended-release niacin/laropiprant), for patients with mixed dyslipidemia and primary hypercholesterolemia, will soon be available in markets such as the UK, Germany and Mexico. Merck noted that the drug is approved in 39 countries outside the USA.

Tredaptive was given the thumbs-up in the European Union last July, based on studies involving more than 4,700 patients which showed that, when added to ongoing statin therapy or alone, the combo lowered ‘bad’ low-density lipoprotein cholesterol and triglyceride levels. It also increased cardioprotective ‘good’ high-density lipoprotein cholesterol levels.

Merck has previously claimed that what differentiates Tredaptive from other such therapies is that it can reduce the side effects of facial flushing associated with current niacin treatment, ie Abbott Laboratories’ Niaspan.

Prospects for the drug on the other side of the Atlantic are less bright. In April 2008, the US Food and Drug Administration issued a not approvable letter for the combo (which Merck wanted to sell as Cordaptive, a name that the agency also rejected) and demanded additional efficacy and safety data.

At the time, the FDA suggested that the company wait for the results of its HPS2-THRIVE cardiovascular outcomes study, which is expected to be completed in January 2013.