Lipid profile improved as predicted
Yet, in regard to an improvement in the lipid profile, pemafibrate performed as predicted. When compared to placebo 4 months into the trial, pemafibrate was associated with median reductions of 26.2% in TGs, 25.8% in VLDL, and 25.6% in remnant cholesterol, which is cholesterol transported in TG-rich lipoproteins after lipolysis and lipoprotein remodeling.
Furthermore, pemafibrate was associated with a median 27.6% reduction relative to placebo in apolipoprotein C-III and a median 4.8% reduction in apolipoprotein E, all of which would be expected to reduce CV risk.
The findings of PROMINENT were published online in the New England Journal of Medicine immediately after their presentation.
The findings of this study do not eliminate any hope for lowering residual CV risk with TG reductions, but they do suggest the relationship with other lipid subfractions is complex, according to Salim S. Virani, MD, PhD, a professor of cardiology at Baylor College of Medicine, Houston.
“I think that the lack of efficacy despite TG lowering may be largely due to a lack of an overall decrease in the apolipoprotein B level,” speculated Dr. Virani, who wrote an editorial that accompanied publication of the PROMINENT results.
He noted that pemafibrate is implicated in converting remnant cholesterol to LDL cholesterol, which might be one reason for a counterproductive effect on CV risk.
“In order for therapies that lower TG levels to be effective, they probably have to have mechanisms to increase clearance of TG-rich remnant lipoprotein cholesterol particles rather than just converting remnant lipoproteins to LDL,” Dr. Virani explained in an attempt to unravel the interplay of these variables.
Although this study enrolled patients “who would be predicted to have the most benefit from a TG-lowering strategy,” Dr. Watson agreed that these results do not necessarily extend to other means of lowering TG. However, it might draw into question the value of pemafibrate and perhaps other drugs in this class for treatment of hypertriglyceridemia. In addition to a lack of CV benefit, treatment was not without risks, including a higher rate of thromboembolism and adverse renal events.
Dr. Das Pradhan reported financial relationships with Denka, Medtelligence, Optum, Novo Nordisk, and Kowa, which provided funding for this trial. Dr. Watson reported financial relationships with Amarin, Amgen, Boehringer-Ingelheim, and Esperion.