Metabolism and Disposition of Volanesorsen, a 2'-O-(2 methoxyethyl) Antisense Oligonucleotide, Across Species.

Volanesorsen (previously known as ISIS 304801) is a 20-nucleotide partially 2'-O-(2-methoxyethyl) (2'-MOE)-modified antisense oligonucleotide (ASO) gapmer, which was recently approved in the European Union as a novel, first-in-class treatment in the reduction of triglyceride levels in patients with familial chylomicronemia syndrome. We characterized the absorption, distribution, metabolism, and excretion characteristics of volanesorsen in mice, rats, monkeys, and humans, in either radiolabeled or nonradiolabeled studies. This also included the characterization of all of the observed ASO metabolite species excreted in urine. Volanesorsen is highly bound to plasma proteins that are similar in mice, monkeys, and humans. In all species, plasma concentrations declined in a multiphasic fashion, characterized by a relatively fast initial distribution phase and then a much slower terminal elimination phase following subcutaneous bolus administration. The plasma metabolite profiles of volanesorsen are similar across species, with volanesorsen as the major component. Various shortened oligonucleotide metabolites (5-19 nucleotides long) were identified in tissues in the multiple-dose mouse and monkey studies, but fewer in the [3H]-volanesorsen rat study, likely due to a lower accumulation of metabolites following a single dose in rats. In urine, all metabolites identified in tissues were observed, consistent with both endo- and exonuclease-mediated metabolism and urinary excretion being the major elimination pathway for volanesorsen and its metabolites. SIGNIFICANCE STATEMENT: We characterized the absorption, distribution, metabolism, and excretion (ADME) of volanesorsen, a partially 2'-MOE-modified antisense oligonucleotide, from mouse to man utilizing novel extraction and quantitation techniques in samples collected from preclinical toxicology studies, a 3H rat ADME study, and a phase 1 clinical trial.

Effects of two therapeutic dietary regimens on primary chylomicronemia in paediatric age: a retrospective data analysis.

BACKGROUND/OBJECTIVE: Subjects suffering from lipoprotein lipase (LPL) deficiency show very severe hypertriglyceridemia, often accompanied by recurrent bouts of pancreatitis. Dietary intervention is currently considered first-line treatment of this condition in paediatric age. The aim of our study was to compare the effects of dietary treatment with a low-fat diet alone and a low-fat diet enriched with omega-3-fatty acids. SUBJECTS/METHODS: The data of 11 patients with LPL deficiency who were diagnosed in our lipid clinic between October 1997 and October 2007 were summarised. All patients had been treated with a low-fat diet, and in addition a group of five patients received supplements of omega-3-fatty acids over a period of at least 5 months. RESULTS: After adjustment for pre-intervention TG concentration, there was a statistically significant difference in post-intervention TG concentrations between the interventions, F(1,8)=13.529, P=0.006, partial η2=0.628. Post-intervention-adjusted TG concentrations were statistically significantly greater in the low-fat diet group vs the w3 diet group (P <0.05). CONCLUSIONS: We provide first evidence that a low-fat diet supplemented with omega-3-fatty acids results in a pronounced decrease in TG in paediatric patients affected with LPL deficiency. However, further studies are necessary to evaluate the long-term effects and safety of omega-3-fatty acids.

Creation of Apolipoprotein C-II (ApoC-II) Mutant Mice and Correction of Their Hypertriglyceridemia with an ApoC-II Mimetic Peptide.

Apolipoprotein C-II (apoC-II) is a cofactor for lipoprotein lipase, a plasma enzyme that hydrolyzes triglycerides (TGs). ApoC-II deficiency in humans results in hypertriglyceridemia. We used zinc finger nucleases to create Apoc2 mutant mice to investigate the use of C-II-a, a short apoC-II mimetic peptide, as a therapy for apoC-II deficiency. Mutant mice produced a form of apoC-II with an uncleaved signal peptide that preferentially binds high-density lipoproteins (HDLs) due to a 3-amino acid deletion at the signal peptide cleavage site. Homozygous Apoc2 mutant mice had increased plasma TG (757.5 ± 281.2 mg/dl) and low HDL cholesterol (31.4 ± 14.7 mg/dl) compared with wild-type mice (TG, 55.9 ± 13.3 mg/dl; HDL cholesterol, 55.9 ± 14.3 mg/dl). TGs were found in light (density < 1.063 g/ml) lipoproteins in the size range of very-low-density lipoprotein and chylomicron remnants (40-200 nm). Intravenous injection of C-II-a (0.2, 1, and 5 µmol/kg) reduced plasma TG in a dose-dependent manner, with a maximum decrease of 90% occurring 30 minutes after the high dose. Plasma TG did not return to baseline until 48 hours later. Similar results were found with subcutaneous or intramuscular injections. Plasma half-life of C-II-a is 1.33 ± 0.72 hours, indicating that C-II-a only acutely activates lipolysis, and the sustained TG reduction is due to the relatively slow rate of new TG-rich lipoprotein synthesis. In summary, we describe a novel mouse model of apoC-II deficiency and show that an apoC-II mimetic peptide can reverse the hypertriglyceridemia in these mice, and thus could be a potential new therapy for apoC-II deficiency.

Gestational hyperlipidemia and acute pancreatitis with underlying partial lipoprotein lipase deficiency and apolipoprotein E3/E2 genotype.

We report the case of a patient who experienced extreme recurrent gestational hyperlipidemia. She was diagnosed with partial lipoprotein lipase (LPL) deficiency but without an associated LPL gene mutation in the presence of the apolipoprotein E3/2 genotype. This is the first reported case of extreme gestational hyperlipidemia with a partial LPL deficiency in the absence of an LPL gene mutation and the apolipoprotein E 3/2 genotype. She was managed with strict dietary control and medicated with omega-3 acid ethyl esters. A patient with extreme hyperlipidemia that is limited to the gestational period should be considered partially LPL-deficient. Extreme instances of hyperlipidemia increase the risk of acute pancreatitis, and the effect of parturition on declining plasma lipid levels can be immediate and dramatic. Therefore, decisions regarding the timing and route of delivery with extreme gestational hyperlipidemia are critical and should be made carefully.

Gestational hyperlipidemia and acute pancreatitis with underlying partial lipoprotein lipase deficiency and apolipoprotein E3/E2 genotype

We report the case of a patient who experienced extreme recurrent gestational hyperlipidemia. She was diagnosed with partial lipoprotein lipase (LPL) deficiency but without an associated LPL gene mutation in the presence of the apolipoprotein E3/2 genotype. This is the first reported case of extreme gestational hyperlipidemia with a partial LPL deficiency in the absence of an LPL gene mutation and the apolipoprotein E 3/2 genotype. She was managed with strict dietary control and medicated with omega-3 acid ethyl esters. A patient with extreme hyperlipidemia that is limited to the gestational period should be considered partially LPL-deficient. Extreme instances of hyperlipidemia increase the risk of acute pancreatitis, and the effect of parturition on declining plasma lipid levels can be immediate and dramatic. Therefore, decisions regarding the timing and route of delivery with extreme gestational hyperlipidemia are critical and should be made carefully.

Treatment of primary chylomicronemia due to familial hypertriglyceridemia by omega-3 fatty acids.

Primary familial forms of chylomicronemia can lead to acute life-threatening complications, especially acute pancreatitis. The main aim of therapy is to avoid this so-called chylomicronemia syndrome. In 12 patients with primary chylomicronemia due to familial hypertriglyceridemia, the addition of 2.16 g omega-3 fatty acids over 4 weeks and 4.32 g for 8 weeks resulted in a decrease of serum triglyceride levels from 1,624 +/- 333 to 894 +/- 241 mg/dL after 12 weeks. Cholesterol and triglyceride levels in the chylomicron fraction were reduced concomitantly, the apolipoprotein B-100/B-48 ratio increased, very--low-density lipoprotein (VLDL) triglycerides, VLDL cholesterol, and total cholesterol levels decreased, and low-density lipoprotein (LDL) cholesterol showed a tendency to increase, but this finding did not reach significance. High-density lipoprotein (HDL) cholesterol levels remained unchanged, as did the levels of apolipoproteins A-I, A-II, and E, and lipoprotein(a). Apolipoprotein B levels decreased significantly. The decrease of triglyceride levels to still-elevated concentrations was accompanied by a substantial decrease in plasma and whole-blood viscosity and erythrocyte aggregation, which reached normal values. As in chylomicronemia, complications usually occur at triglyceride levels higher than 1,500 mg/dL; patients can still profit from treatment with omega-3 fatty acids, even though triglyceride levels are still substantially elevated. No clinically relevant side effects occurred, with the exception of the manifestation of diabetes mellitus in one patient, which could be reversed after discontinuation of treatment.