Rosenson RS, et al. Joint American College of Cardiology/Journal of the American Medical Association Late-Breaking Clinical Trials. Presented at: American College of Cardiology Scientific Session; May 15-17, 2021 (virtual meeting).
The study was funded by Regeneron. Rosenson reports he received grants and/or personal fees from 89Bio, Amgen, CVS Caremark, Kowa, Novartis, Regeneron, The Medicines Company and UpToDate; and holds equity in MediMergent.
In a phase 2 study, evinacumab reduced triglyceride levels in patients with severe hypertriglyceridemia but not familial chylomicronemia syndrome, a speaker reported at the American College of Cardiology Scientific Session.
Robert S. Rosenson
The reductions after treatment with evinacumab (Evkeeza, Regeneron) were evident in certain patients from two cohorts of multifactorial chylomicronemia syndrome, but not in patients from a cohort of familial chylomicronemia syndrome, Robert S. Rosenson, MD, director of cardiometabolic disorders at The Mount Sinai Hospital and professor of medicine at Icahn School of Medicine at Mount Sinai, said during the presentation.
“We investigated individuals with triglyceride levels greater than 1,000 mg/dL who were hospitalized for acute pancreatitis,” Rosenson told Healio. “These are individuals who are at extremely high risk for recurrent acute pancreatitis. In individuals who have had one or more episodes, the risk [for recurrent acute pancreatitis] increases dramatically to about 20% within 1 year, and for people who had had two or more episodes, the incidence of recurrent acute pancreatitis is about 40%. These are individuals who struggle to lower their triglycerides because they often have mutations that don’t respond to the conventional therapies. Individuals with severe hypertriglyceridemia will worsen with fat, both dietary fat and supplemental fat such as that found in fish oil capsules, a therapy often used for lowering triglycerides. There is a tremendous unmet need.”
Phase 2 results
Evinacumab is a human monoclonal antibody that binds to and blocks angiopoietin-like 3 (ANGPTL3). Evinacumab is approved by the FDA for use in homozygous familial hypercholesterolemia but not for patients with familial or multifactorial chylomicronemia syndrome.
The current study included 51 patients (53% men) with severe hypertriglyceridemia and at least one hospitalization for acute pancreatitis who were divided into three cohorts:
- those with familial chylomicronemia syndrome who had bi-allelic loss-of-function mutations in APOA5, APOC2, GPIHBP1, LMF1, or LPL (cohort 1);
- those with multifactorial chylomicronemia syndrome who had heterozygous loss-of-function mutations in APOA5, APOC2, GPIHBP1, LMF1, or LPL (cohort 2); and
- those with multifactorial chylomicronemia syndrome but no lipoprotein lipase pathway mutations (cohort 3).
“Familial chylomicronemia syndrome is rare, about 1 in 1 million, but the other conditions are about 1 in 5,000,” Rosenson told Healio.
Patients were randomly assigned on a 2:1 basis to evinacumab 15 mg/kg or placebo every 4 weeks for 12 weeks (double-blind treatment period), followed by evinacumab for all patients every 4 weeks for 12 weeks (single-blind treatment period), followed by a 20-week safety follow-up period.
The primary endpoint was intra-patient change in serum triglyceride levels between baseline and 12 weeks (after the double-blind period for those assigned evinacumab and after the single-blind period for those assigned placebo) in cohort 3. In that cohort, the least squares mean reduction in triglycerides from baseline to 12 weeks was –27.1% (standard error, 37.4; 95% CI, –71.2 to 84.6) and the median reduction was –68.8% (95% CI, –84.1 to –38.8), Rosenson said.
Median change in triglycerides during the double-blind period was –64.8% in the evinacumab group and 9.4% in the placebo group in cohort 2 (P = .0076) and –80.9% in the evinacumab group and 80.9% in cohort 3 (P = .0418), he said. There was no difference in median change in triglycerides in cohort 1 (P = .9495).
“Disinhibiting the activity of an enzyme that’s non-functioning isn’t going to do anything,” Rosenson said. “But in the other groups, evinacumab was very effective at lowering triglycerides.”
Treatment-emergent adverse events were similar in the evinacumab and placebo groups, Rosenson said. In the double-blind treatment period, 8.6% of the evinacumab group and 12.5% of the placebo group had acute pancreatitis events.
“We learned something different from the studies of evinacumab in patients with hypercholesterolemia,” Rosenson told Healio. “In this study, at 4 weeks, not everybody had detectable levels of evinacumab. Thus, the triglyceride levels went up in those individuals and they had recurrent acute pancreatitis. What the study is telling us is that in patients with severe hypertriglyceridemia, a higher dose of evinacumab will be needed to maintain the drug levels over a 4-week period of time.”
Therefore, he said in an interview, a phase 2b study of evinacumab 20 mg/kg every 4 weeks for reduction of acute pancreatitis is being launched.
He noted most patients from the multifactorial chylomicronemia syndrome cohorts had CHD in addition to severe hypertriglyceridemia, and evinacumab “is working on both risks, and I think that is a very important breakthrough for these patients.”