Nine patients (27%) discontinued the study due to adverse events (AE). Five of the discontinuations were related to platelet reductions with the other four related to nonplatelet-related adverse events.
COMPASS
The COMPASS study primarily looked at patients without FCS, but severe hypertriglyceridemia, to evaluate the safety and efficacy of volanesorsen in a similarly ill, but less severe, population over a 6 month study period. Patients with FCS had baseline fasting plasma triglyceride levels of 2,644 mg/dL and 2,134 mg/dL in the placebo and volanesorsen groups, respectively. This is nearly double what was seen in non-FCS patients in the study, and is 14-17 higher than the upper limit of normal (ULN).
Researchers enrolled 114 patients and randomized them 2:1 to receive volanesorsen or placebo. This led to 75 patients taking volanesorsen and 34 placebo.
The efficacy results were similar to those in the FCS-focused APPROACH trial, with volanesorsen treatment leading to reductions in triglyceride levels after 3 months, with further reductions over the 6-month study treatment.
Weekly treatment with volanesorsen reduced triglycerides by nearly 71% in the total patient population, compared to placebo, which only achieved a 0.9% decrease in triglycerides. These reductions were conserved at the end of week 26 in patients who had to reduce their dosing to biweekly (62%) and patients who maintained weekly dosing treatments (78%). Overall, a greater than 40% reduction of fasting triglyceride levels after 3 months of treatment was achieved in 87% of volanesorsen-treated patients, compared to 13% of placebo-treated patients (P < 0.0001).
Serious adverse events (SAEs) occurred in nine patients (8%). In the placebo group, two patients (5%) reported acute pancreatitis. Apart from the bouts of pancreatitis, some of the most common AEs were decreased platelet count, thrombocytopenia, and nasopharyngitis.
APPROACH OPEN LABEL
The open label portion of the APPROACH study is ongoing and was designed to assess the safety and efficacy of extended treatment with volanesorsen in patients with FCS who had previously completed APPROACH or COMPASS studies or had never received volanesorsen treatment. Patients received 300 mg of volanesorsen once weekly for 52 weeks. Patients who completed the trial were eligible to continue treatment for an additional 52 weeks or until a product is available. As of August 31, 2017, after the data cutoff, 60 patients were enrolled.
The results of this open label portion of the APPROACH trial were similar to that of the APPROACH trial itself. Patients who transitioned from APPROACH or COMPASS showed decreases in their open label extension (OLE) baseline triglyceride measurements to OLE month 3 of 48.1% and 52.1%, respectively. Treatment-naive patients displayed a nearly 60% decrease in their triglyceride levels 3 months.
Of the 60 patients who started the study, 12 have discontinued the study prematurely. The majority of patients, eight, who discontinued did so because of adverse events and four withdrew voluntarily.
Adverse events were not uncommon, with 56 patients (93%) experiencing an AE during the course of the study. Some of the most common AEs were decreased platelet count, thrombocytopenia, and nasopharyngitis.
Akcea has developed a Risk Evaluation and Mitigation program to mitigate the risk of serious bleeding related to severe thrombocytopenia with volanesorsen use in patients with FCS.
Panelist Susan Z. Yanovksi, MD , of the National Institutes of Health, said she voted no over safety concerns, but felt conflicted.
“There’s no question that volanesorsen is effective in dramatically reducing triglycerides, but I had a lot of concerns whether the data presented by the sponsor actually established favorable risk-benefit ratio.”