FROM THE AHA SCIENTIFIC SESSIONS
CSL112, a plasma-derived apolipoprotein A-1 (apoA-1) that enhances cholesterol efflux capacity, was found safe for use after acute MI in a manufacturer-sponsored phase IIb trial, Michael Gibson, MD, reported at the American Heart Association scientific sessions.
Cholesterol efflux capacity is a measure of HDL cholesterol’s ability to remove excess cholesterol from atherosclerotic plaque for transport to the liver. Drugs that improve this capacity rather than simply raising HDL cholesterol are expected to reduce plaque burden and stabilize vulnerable plaque immediately following acute MI, when cholesterol efflux is significantly impaired. But they have not been tested in this patient population until now, said Dr. Gibson of Beth Israel Deaconess Medical Center and Harvard, both in Boston.
An earlier prototype formulation of CSL112 was discontinued because of concerns about transient elevations in liver enzymes and the potential for renal toxicity due to the agent’s high sucrose content. Dr. Gibson and his associates in the AEGIS-1 trial (ApoA-1 Event Reducing in Ischemic Syndromes 1) now report their findings for the current formulation of CSL112, which contains lower phosphatidylcholine and lower sucrose levels, in 1,258 patients who had MI during the preceding week and who had normal or only mildly impaired renal function. These results were reported at the meeting and simultaneously published online in Circulation (2016, Nov 15. doi: 10.1161/CIRCULATION AHA.116.025687 ).
The study participants were enrolled in 16 countries during an 11-month period. They were randomly assigned to receive low-dose (2 g) CSL112 (419 patients), high-dose (6 g) CSL112 (421 patients), or a matching placebo (418 patients) via IV infusion every week for 4 consecutive weeks. The median duration of follow-up at the time of this report was 7.5 months.
The two primary safety end points – the rate of hepatic impairment and the rate of renal impairment during treatment – were not significantly different across the three study groups. Hepatic impairment developed in 1.0% of the low-dose group, 0.5% of the high-dose group, and 0.0% of the placebo group. Renal impairment developed in 0.0% of the low-dose group, 0.7% of the high-dose group, and 0.2% of the placebo group.
Similarly, rates of major adverse cardiovascular events were comparable across the three study groups, as were rates of any grade of bleeding, rates of serious and life-threatening adverse events, and rates of adverse events leading to drug discontinuation.
This study focused on safety and tolerability and was not designed or powered to assess efficacy. Nevertheless, CSL112 caused a substantial and dose-dependent increase in both apoA-1 and cholesterol efflux capacity. The low-dose drug raised total cholesterol efflux capacity by 1.87-fold, and the high-dose drug raised it 2.45-fold.
As the first study to establish the safety and feasibility of adding CSL112 to standard care for acute MI, this trial demonstrates that an adequately powered, multicenter, phase III trial is warranted, Dr. Gibson said.
The current formulation of CSL112 didn’t provoke hepatic toxicity, and even though it was given shortly after contrast studies in MI patients, it also didn’t provoke renal toxicity. “This demonstrates the feasibility of administering CSL112 to patients with MI who have normal renal function or mild renal impairment shortly after angiography. A study in MI patients who have moderate renal impairment is now under way,” he noted.
This study was sponsored by CSL Behring, maker of CSL112. Dr. Gibson and his associates reported financial ties to Behring and numerous other industry sources.