Merck's Tredaptive (formerly Cordaptive) has had a long and troubled history. It's a combination of niacin and Laropiprant, which is there to try to reduce the cardiovascular (flushing) side effects of large niacin doses, which otherwise seem to do a good job improving lipid profiles. (Mind you, we don't seem to know how that works, and there's a lot of reason to wonder how well it works in combination with statins, but still).
The combination was rejected by the FDA back in 2008, but approved in Europe. Merck has been trying to shore up the drug ever since, and since the FDA told them that they would not approve without more data, the company has been running a 25,000-patient trial (oh, cardiovascular disease. . .) combining Tredaptive with statin therapy. In light of the last link in the paragraph above, one might have wondered how that was going to work out, since the NIH had to stop a large niacin-plus-statin study of their own. Well. . .
The European Medicines Agency has started a review of the safety and efficacy of Tredaptive, Pelzont and Trevaclyn, identical medicines that are used to treat adults with dyslipidaemia (abnormally high levels of fat in the blood), particularly combined mixed dyslipidaemia and primary hypercholesterolaemia.
The review was triggered because the Agency was informed by the pharmaceutical company Merck, Sharp & Dohme of the preliminary results of a large, long-term study comparing the clinical effects of adding these medicines to statins (standard medicines used to reduce cholesterol) with statin treatment alone. The study raises questions about the efficacy of the medicine when added to statins, as this did not reduce the risk of major vascular events (serious problems with the heart and blood vessels, including heart attack and stroke) compared with statin therapy alone. In addition, in the preliminary results a higher frequency of non-fatal but serious side effects was seen in patients taking the medicines than in patients only taking statins.
So much for Tredaptive, and (I'd say) so much for the idea of taking niacin and statins together. And it also looks like the FDA was on target here when they asked for more evidence from Merck. Human lipid biology, as we get reminded over and over, is very complicated indeed. The statin drugs, for all their faults, do seem to be effective, but (to repeat myself!) they also seem, more and more, to be outliers in that regard.