The present study is the first intervention study in a well-established, translational mouse model for hyperlipidaemia and atherosclerosis showing that anacetrapib dose-dependently reduces atherosclerosis development and adds to the anti-atherogenic effects of atorvastatin. This effect is mainly ascribed to the reduction in non-HDL-C despite a remarkable increase in HDL-C and without affecting HDL functionality. In addition, anacetrapib improves lesion stability.

The online-only Data Supplement is available with this article at http://hyper.ahajournals.org/lookup/suppl

The goal of cancer-drug delivery is to achieve high levels of therapeutics within tumors with minimal systemic exposure that could cause toxicity. Producing biologics directly in situ where they diffuse and act locally is an attractive alternative to direct administration of recombinant therapeutics, as secretion by the tumor itself provides high local concentrations that act in a paracrine fashion continuously over an extended duration (paracrine delivery). We have engineered a SHielded, REtargeted ADenovirus (SHREAD) gene therapy platform that targets specific cells based on chosen surface markers and converts them into biofactories secreting therapeutics. In a proof of concept, a clinically approved antibody is delivered to orthotopic tumors in a model system in which precise biodistribution can be determined using tissue clearing with passive CLARITY technique (PACT) with high-resolution three-dimensional imaging and feature quantification within the tumors made transparent. We demonstrate high levels of tumor cell–specific transduction and significant and durable antibody production. PACT gives a localized quantification of the secreted therapeutic and allows us to directly observe enhanced pore formation in the tumor and destruction of the intact vasculature. In situ production of the antibody led to an 1,800-fold enhanced tumor-to-serum antibody concentration ratio compared to direct administration. Our detailed biochemical and microscopic analyses thus show that paracrine delivery with SHREAD could enable the use of highly potent therapeutic combinations, including those with systemic toxicity, to reach adequate therapeutic windows.

Torcetrapib induces a sustained impairment of endothelial function, decreases eNOS mRNA, protein as well as NO release, stimulates vascular ROS and ET production, an effect that is prevented by chronic ET(A/B)-receptor blockade. These unexpected off-target effects of torcetrapib need to be ruled out in the clinical development of novel CETP inhibitors, particularly before a large patient population at increased cardiovascular risk is exposed to these compounds.

The plasma levels of high-density lipoprotein (HDL) cholesterol are inversely related to cardiovascular risk. Traditional HDL-raising therapies, like fibrates, PPAR-γ agonists, and nicacin, among others, are associated with undesirable side effects, limited efficacy, or have not yet been shown to improve morbidity and mortality on top of statins in clinical outcome trials. A novel pharmacological target for raising circulating HDL-C levels is the cholesterol ester transfer protein (CETP), an enzyme that facilitates the transport of cholesteryl esters and triglycerides between the lipoproteins. Four pharmacological small-molecule inhibitors of CETP, i.e. torcetrapib (Pfizer), dalcetrapib (JTT-705; Roche), anacetrapib (Merck), and evacetrapib (Eli Lilly) have been developed. Notwithstanding a marked increase in HDL, torcetrapib was associated with an increase in all-cause mortality in the ILLUMINATE trial and raised safety concerns related to the off-target effects of CETP inhibition. Most recently, development of dalcetrapib was abruptly stopped due to a lack of clinically meaningful efficacy. Thus, it will be of utmost importance to demonstrate that the remaining CETP inhibitors in development not only increase HDL-C levels in plasma, but also improve HDL-function in patients with coronary disease or an acute coronary syndrome.