SILVER SPRING, Md. – A novel drug to treat a rare metabolic disorder was recommended for approval by the Endocrinologic and Metabolic Drugs Advisory Committee in a May 10 meeting.
Advisors voted 12 to 8 to recommend volanesorsen, a novel antisense drug, as an adjunct to diet for the treatment of familial chylomicronemia syndrome (FCS).
“The sponsor provided compelling evidence that the drug lowers triglyceride levels, substantially,” said panelist Jean-Pierre Raufman, MD, of the University of Maryland. I think that there is clearly a group of patients with this disease that can benefit from this agent.”
FCS is an extremely rare genetic disorder characterized by severe hypertriglyceridemia and recurrent pancreatitis caused by a deficiency in lipoprotein lipase. Pancreatitis in the setting of hypertriglyceridemia is particularly severe, often leading to multi-organ failure, pancreatic necrosis, and death.
Volanesorsen targets apolipoprotein C-III (apoC-III), a key regulator of lipoprotein lipase, the essential enzyme involved in chylomicron and triglyceride clearance.
Because of the small number of patients affected, estimated at just 3,000-5,000 patients worldwide, the FDA considers FCS to be an orphan disease .
The application, submitted by Akcea Pharmaceuticals, was based on the results of several phase 3 clinical trials conducted both in FCS patients and, because of the rarity of the disorder, patients with high triglycerides. The APPROACH study looked at patients with FCS. The COMPASS study examined patients with hypertriglyceridemia . Additionally, an ongoing, open-label extension of the APPROACH study examined patients with FCS who had completed APPROACH, COMPASS, and FCS patients who had not participated in a previous volanesorsen trial.
APPROACH APPROACH was a phase 3, double-blind clinical trial to assess the safety and efficacy of volanesorsen in patients with FCS. Because of the extremely small number of patients affected by FCS, non-FCS patients with hypertriglyceridemia were included in the trial.
All patients who had completed a 6 week diet, lifestyle, and medication stabilization period were enrolled in the study. In total, 67 patients were randomized to receive a weekly, subcutaneous 300 mg dose of volanesorsen or a placebo for 52 weeks. Due to the risk of platelet reduction, the study allowed for dosing schedule interruptions or pauses, if needed. To assess efficacy, the study looked at the percent change in fasting triglycerides at month 3 of the study in all randomized patients who received at least one dose of the study drug and who had baseline fasting plasma trigylcerides recorded.
Volanesorsen proved quite effective in reducing fasting triglyceride levels, with a 94% (P < 0.0001) reduction in plasma concentrations at 3 months, compared with placebo.
The effectiveness of volanesorsen extended beyond month 3, with statistically significant reductions in triglyceride concentrations at both month 6 and month 12 compared with placebo. Patients taking volanesorsen had 53% and 40% reductions at month 6 and 12 compared to baseline. Conversely, patients taking placebo experienced increases of 25% and 9%, respectively. The differences between volanesorsen and placebo patients at month 6 (–78%) and month 12 (–49%) were both statistically significant.
Another important finding from this study was that 77% of patients responded to treatment, evidenced by a reduction of triglyceride levels greater than 750 mg/dL, a much better response than the 10% of placebo patients (P =.0001).