November 5th, 2012

Early Look: New Methods to Enhance Cholesterol Efflux

Although clinical trials of HDL-boosting CETP inhibitors have so far failed to produce positive results, many other avenues of HDL-related research remain active. Conference attendees got a glimpse of the very early phases of two intriguing lines of research in this area on Monday.

Apoliporotein A-I is thought to be the key HDL component that removes cholesterol from cells. Almost a decade ago, a study demonstrating regression of atherosclerosis with apo A-I Milano caused tremendous excitement, but the recombinant product has not yet undergone further research or commercial development. A somewhat similar approach is now being developed by by CSL Limited with a novel formulation of human apo A-I, known as CSL112. At the AHA, Andreas Gille and colleagues reported giving CSL112 to healthy volunteers and observing dramatic increases in the ability of the HDL in their blood plasma to remove cholesterol from cells.

Gille reported that the increase in cholesterol efflux capacity was higher and occurred faster than any previous therapy, more than doubling within two hours, as opposed to a 2.9% increase after 4 weeks with niacin or 6.8% after 24 months with dalcetrapib. “CSL112 may offer a novel means to rapidly remove cholesterol from plaque following a heart attack,” said Gille. To date, two phase 1 studies have demonstrated a favorable safety profile, he reported. A phase 2 study of CSL112 in patients with an acute coronary syndrome is planned.

An even more unusual approach is being explored by Alan Fogelman and his team, who have genetically engineered a tomato to produce a small peptide, 6F, that mimics the action of apo A-I. They then fed the tomatoes to mice with high LDL levels. After consuming the tomatoes along with a high-fat and high-calorie diet, a number of signs suggested a beneficial effect, including significantly lower levels of inflammation, higher levels of the antioxidant paraoxonase, higher HDL levels, and less atherosclerotic plaque.

“To our knowledge this is the first example of a drug with these properties that has been produced in an edible plant and is biologically active when fed without any isolation or purification of the drug,” Fogelman said in an AHA press release.

For related CardioExchange content, go to our AHA 2012 Headquarters page.

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