BackgroundVolanesorsen, an antisense oligonucleotide, is designed to inhibit hepatic apolipoprotein C-III synthesis and reduce plasma apolipoprotein C-III and triglyceride concentrations. ObjectiveThe present study assessed efficacy and safety of volanesorsen in patients with familial partial lipodystrophy (FPLD) and concomitant hypertriglyceridemia and diabetes. MethodsBROADEN was a randomized, placebo-controlled, phase 2/3, 52-week study with open-label extension and post-treatment follow-up periods. Patients received weekly subcutaneous volanesorsen 300 mg or placebo. The primary endpoint was percent change from baseline in fasting triglycerides at 3 months. Secondary endpoints included relative percent change in hepatic fat fraction (HFF), visceral adiposity, and glycated hemoglobin levels. ResultsForty patients (11 men, 29 women) were enrolled, majority of whom were aged <65 years (mean, 47 years) and White. Least squares mean (LSM) percent change in triglycerides from baseline to 3 months was −88% (95% CI, −134 to −43) in the volanesorsen group versus –22% (95% CI, −61 to 18) in the placebo group, with a difference in LSM of −67% (95% CI, –104 to –30; P=0.0009). Volanesorsen induced a significant LSM relative reduction in HFF of 53% at month 12 versus placebo (observed mean [SD]: 9.7 [7.65] vs. 18.0 [8.89]; P=0.0039). No statistically significant changes were noted in body volume measurements (fat, liver, spleen, visceral/subcutaneous adipose tissue) or glycated hemoglobin. Serious adverse events in patients assigned to volanesorsen included 1 case each of sarcoidosis, anaphylactic reaction, and systemic inflammatory response syndrome. ConclusionIn BROADEN, volanesorsen significantly reduced serum triglyceride levels and hepatic steatosis in patients with FPLD.