Inhibition of Angiopoietin-Like 3 (ANGPTL3) Reduces Adipose Tissue Insulin Resistance in Patients With Familial Partial Lipodystrophy

Familial partial lipodystrophy (FPLD) is a rare disease characterized by selective loss of peripheral subcutaneous fat, usually affecting the trunk and limbs, but preservation in other areas, such as the face and neck. It is usually associated with dyslipidemia and diabetes mellitus, and currently, there are no approved specific therapies for this disease in the US. Reductions in circulating levels of ANGPTL3 either by homologous loss-of-function mutations in humans or by pharmacological inhibition in rodents are associated with reductions in triglyceride (and other atherogenic lipid) levels and protect from atherosclerosis, making it an attractive target for patients with FPLD and metabolic dyslipidemia. We performed a proof-of-concept study to assess the early efficacy and safety of targeting ANGPTL3 via antisense oligonucleotide ISIS-703802 (vupanorsen) in a small number of patients with FPLD. Four patients with FPLD (3F/1M; age range: 39–48; 1 with LMNA R482Q, 1 with LMNA R584H, and 2 with no causative genetic variant), diabetes (HbA1c>6.5%) and hypertriglyceridemia (>250 mg/dL at screening) were included. Patients received the study drug at a subcutaneous dose of 20 mg weekly for 26 weeks. The primary endpoint was the change in triglycerides at week 27. Other end-points of interest measured at the same time points included insulin secretion, sensitivity, lipid and hormonal changes in response to a 5 hour long mixed meal test and body composition measured by dual energy absorptiometry (DEXA). Treatment resulted in a 59.9±26.3 (mean±SD) % of reduction in triglycerides, 54.7±9.8% of reduction in serum ANGPTL3 levels and 50.8±27.4% of reduction in ApoCIII. Treatment with vupanorsen led to a reduction of 209.3±120.4 in adipose tissue insulin resistance (ADIPO-IR) from a baseline of 470.3±114.3 and the area under the curve (AUC) for circulating free fatty acid levels were decreased by 32.1±21.4 mmol/L/min from a baseline of 215.8±55.2 mmol/L/min. Glucose AUC and triglyceride AUC also decreased after treatment (-14.0±5.2 and -60.1±26.5 mg/dL/min, respectively). Analyzing body fat distribution using DEXA, we observed that the fat mass index (FMI) and trunk mass index (TMI) did not change from baseline, but the ratio of total fat mass/ fat mass from limbs decreased by 10.7±12.2. These data show a tendency for redistribution of central body fat to limbs. There were numerous adverse events observed that were related to common serious complications associated with diabetes and FPLD. Although limited, these results suggest that targeting ANGPTL3 with vupanorsen in patients with FPLD may have a therapeutic role by addressing multiple problems.