These drugs have generally failed in clinical trials, either causing a marked increase in deaths (torcetrapib), or having no meaningful clinical improvement despite HDL increases (dalcetrapib, evacetrapib).
Dalcetrapib: development halted in May 2012 when Phase III trials failed to show clinically meaningful efficacy.[6]
Evacetrapib: development discontinued in 2015 due to insufficient efficacy.[7]
Others:
Anacetrapib: In 2017, the REVEAL trial based on more than 30,000 participants showed a modest benefit of the addition of anacetrapib to statin therapy.[8]Merck halted the development of the drug in 2017, concluding it wasn't sufficiently effective to be a competitive product.[9][10]
Obicetrapib (TA-8995, AMG-899): Phase II results were reported in 2015 and Phase III trials beginning in 2023.[11][needs update]
CETP inhibitors inhibit cholesterylester transfer protein (CETP), which normally transfers cholesterol from HDL cholesterol to very low density or low density lipoproteins (VLDL or LDL). Inhibition of this process results in higher HDL levels and reduces LDL levels.[12] CETP inhibitors do not reduce rates of mortality, heart attack, or stroke in patients already taking a statin.[13]
Pharmacogenomics
In 2015, a pharmacogenomic sub-study of the dal-OUTCOMES clinical trial on 5,749 individuals identified a genetic variant in the ADCY9 gene which modulates response to dalcetrapib. In patients with the rs1967309 'AA' genotype, there was a significant reduction in the rate of cardiovascular events in the dalcetrapib arm whereas non-carriers were at increased risk.[14] Beginning in 2015, the efficacy of dalcetrapib in the genetic sub-population was being investigated in the dal-GenE trial.[15][needs update]
^Tall AR (March 2007). "CETP inhibitors to increase HDL cholesterol levels". The New England Journal of Medicine. 356 (13): 1364–1366. doi:10.1056/NEJMe078029. PMID17387130.
^Rennings AJ, Stalenhoef A (October 2008). "JTT-705: is there still future for a CETP inhibitor after torcetrapib?". Expert Opinion on Investigational Drugs. 17 (10): 1589–1597. doi:10.1517/13543784.17.10.1589. PMID18808319. S2CID5781222.
^Hovingh GK, Kastelein JJ, van Deventer SJ, Round P, Ford J, Saleheen D, et al. (August 2015). "Cholesterol ester transfer protein inhibition by TA-8995 in patients with mild dyslipidaemia (TULIP): a randomised, double-blind, placebo-controlled phase 2 trial". Lancet. 386 (9992): 452–460. doi:10.1016/S0140-6736(15)60158-1. hdl:1887/117246. PMID26047975. S2CID7540974.