Mipomersen, an antisense oligonucleotide that reduces hepatic production of apoB, has been shown in phase 2 studies to decrease plasma apoB, LDL cholesterol (LDL-C), and triglycerides. ApoC-III inhibits VLDL and LDL clearance, and it stimulates inflammatory responses in vascular cells. Concentrations of VLDL or LDL with apoC-III independently predict cardiovascular disease. We performed an exploratory posthoc analysis on a subset of hypercholesterolemic subjects obtained from a randomized controlled dose-ranging phase 2 study of mipomersen receiving 100, 200, or 300 mg/wk, or placebo for 13 wk (n = 8 each). ApoC-III–containing lipoproteins were isolated by immuno-affinity chromatography and ultracentrifugation. Mipomersen 200 and 300 mg/wk reduced total apoC-III from baseline by 6 mg/dl (38–42%) compared with placebo group (P < 0.01), and it reduced apoC-III in both apoB lipoproteins and HDL. Mipomersen 100, 200, and 300 mg doses reduced apoB concentration of LDL with apoC-III (27%, 38%, and 46%; P < 0.05). Mipomersen reduced apoC-III concentration in HDL. The drug had no effect on apoE concentration in total plasma and in apoB lipoproteins. In summary, antisense inhibition of apoB synthesis reduced plasma concentrations of apoC-III and apoC-III–containing lipoproteins. Lower concentrations of apoC-III and LDL with apoC-III are associated with reduced risk of coronary heart disease (CHD) in epidemiologic studies independent of traditional risk factors.

AIMS Mipomersen, an apolipoprotein (apo) B synthesis inhibitor, has been shown to produce potent reductions in apoB and LDL-cholesterol levels in animal models as well as healthy human volunteers. A randomized, double-blind, placebo-controlled, dose-escalation study was designed to evaluate the efficacy and safety of mipomersen monotherapy with or without dose loading in subjects with mild-to-moderate hyperlipidaemia. METHODS AND RESULTS Fifty subjects with LDL-cholesterol levels between 119 and 266 mg/dL were enrolled into five cohorts at a 4:1 randomization ratio of active to placebo. Two 13-week dose regimens were evaluated at doses ranging from 50 to 400 mg/week. Mipomersen produced dose-dependent reductions in all apoB containing lipoproteins. In the 200 and 300 mg/week dose cohorts, mean reductions from baseline in LDL cholesterol were -45 ± 10% (P= 0.000) and -61 ± 8% (P= 0.000), corresponding to a -46 ± 11% (P= 0.000) and -61 ± 7% (P= 0.000) decrease in apoB levels. Triglyceride levels were also lowered with median reductions up to 53% (P= 0.021). The most common adverse events were injection site reactions. Seven of 40 subjects (18%) showed consecutive transaminase elevations >3× upper limit of normal. Five of these subjects received 400 mg/week, four of whom had apoB levels below the limit of detection. As a consequence, the 400 mg/week cohort was discontinued. CONCLUSIONS Mipomersen administered as monotherapy in subjects with mild-to-moderate hyperlipidaemia produced potent reductions in all apoB-containing lipoproteins. Higher doses were associated with hepatic transaminase increases.

Objectives The aim of this study was to evaluate the efficacy and safety of mipomersen in hypercholesterolemic subjects taking stable statin therapy.Background Mipomersen is an apolipoprotein (apo) B synthesis inhibitor that has demonstrated significant reductions in apo B and low-density lipoprotein (LDL) cholesterol in Phase 1 clinical trials in healthy volunteers.Methods A randomized, placebo-controlled, dose-escalation Phase 2 study was designed to evaluate the effects of mipomersen in hypercholesterolemic subjects taking stable statin therapy. Seventy-four subjects were enrolled sequentially into 1 of 6 dose cohorts at a 4:1 (active/placebo) ratio. Subjects received 7 doses of 30 to 400 mg over 5 weeks in the first 5 cohorts and 15 doses of 200 mg over 13 weeks in the sixth cohort. Pre-specified end points included percentage change from baseline in apo B and LDL cholesterol. Safety was assessed with laboratory test results and by the incidence and severity of adverse events.Results The apo B and LDL cholesterol were reduced by 19% to 54% and 21% to 52%, respectively, at doses of 100 mg/week mipomersen and higher in the 5-week treatment cohorts. Efficacy seemed to increase upon treatment for 13 weeks at a dose of 200 mg/week. Injection site reactions (mild to moderate erythema [90%]) and hepatic transaminase increases (17%) were the most common adverse events, leading to discontinuation in 2 subjects and 1 subject, respectively. In the 13-week treatment cohort, 5 of 10 subjects (50%) had elevations >= 3x the upper limit of normal, 4 of which persisted on 2 consecutive occasions.Conclusions Mipomersen might hold promise for treatment of patients not reaching target LDL cholesterol levels on stable statin therapy. Further studies are needed to address the mechanisms and clinical relevance of transaminase changes after mipomersen administration. (Dose-Escalating Safety Study in Subjects on Stable Statin Therapy; NCT00231569) (J Am Coll Cardiol 2010;55:1611-8) (C) 2010 by the American College of Cardiology Foundation

Mipomersen sodium (ISIS 301012) is a 20-mer phosphorothioate antisense oligonucleotide that is complementary to human apolipoprotein B-100 (apoB-100) messenger RNA and subsequently reduces translation of ApoB-100 protein, the major apolipoprotein of very low-density lipoprotein, intermediate-density lipoprotein and low-density lipoprotein (LDL). Mipomersen sodium is currently being studied in phase II/III clinical studies to determine its clinical utility as add-on therapy to HMG-CoA reductase inhibitors or other lipid-lowering agents in subjects with hypercholesterolaemia. The aim of this study was to characterize the pharmacokinetic interactions of mipomersen sodium with simvastatin and ezetimibe. Another aim was to evaluate the ability of mipomersen sodium to inhibit major cytochrome P450 (CYP) isoenzymes in vitro.

The in vivo pharmacokinetics/pharmacodynamics of 2'-O-(2-methoxyethyl) (2'-MOE) modified antisense oligonucleotides (ASOs), targeting apolipoprotein B-100 (apoB-100), were characterized in multiple species. The species-specific apoB antisense inhibitors demonstrated target apoB mRNA reduction in a drug concentration and time-dependent fashion in mice, monkeys, and humans. Consistent with the concentration-dependent decreases in liver apoB mRNA, reductions in serum apoB, and LDL-C, and total cholesterol were concurrently observed in animal models and humans. Additionally, the long duration of effect after cessation of dosing correlated well with the elimination half-life of 2'-MOE modified apoB ASOs studied in mice (t(1/2) congruent to 20 days) and humans (t(1/2) congruent to 30 days) following parental administrations. The plasma concentrations of ISIS 301012, observed in the terminal elimination phase of both mice and monkeys were in equilibrium with liver. The partition ratios between liver and plasma were similar, approximately 6000:1, across species, and thus provide a surrogate for tissue exposure in humans. Using an inhibitory E-max model, the ASO liver EC50s were 101 +/- 32, 119 +/- 15, and 300 +/- 191 mu g/g of ASO in high-fat-fed (HF) mice, transgenic mice containing the human apoB transgene, and monkeys, respectively. The estimated liver EC50 in man, extrapolated from trough plasma exposure, was 81 +/- 122 mu g/g. Therefore, extraordinary consistency of the exposure-response relationship for the apoB antisense inhibitor was observed across species, including human. The cross-species PK/PD relationships provide confidence in the use of pharmacology animal models to predict human dosing for second-generation ASOs targeting the liver. (C) 2008 Elsevier Inc. All rights reserved.

BACKGROUND & AIMS:The aim of this study was to compare the safety and efficacy of alicaforsen, a first-generation antisense inhibitor of intercellular adhesion molecule 1, with placebo in subjects with active Crohn's disease, a disorder in which intercellular adhesion molecule 1 is overexpressed. METHODS:In 2 identical double-masked, placebo-controlled studies, 331 subjects with active Crohn's disease were treated with either alicaforsen (221 subjects) or placebo (110 subjects) administered via 2-hour intravenous infusion 3 times a week for 4 weeks. Patients then returned for follow-up every 2 weeks. The primary end point was clinical remission by week 12. Secondary end points included clinical response and remission in relation to previous use of other biologics including tumor necrosis factor-alpha antagonists and presence of fistulous disease. RESULTS:The results, whether combined or analyzed individually, failed to demonstrate statistical significance as a measure of its primary outcome (alicaforsen 33.9% vs placebo 34.5%; P = .89). In addition, no statistical differences in response were observed between alicaforsen and placebo in subjects who were previously treated with anti-tumor necrosis factor-alpha therapy or had baseline fistulizing disease. There were no significant differences in adverse events from placebo apart from a higher infusion reaction rate. CONCLUSIONS:In the subject population studied, alicaforsen failed to demonstrate efficacy in any of its primary outcome measures. Alicaforsen was well-tolerated.

BACKGROUND:Apolipoprotein B (apoB) is an important structural component of low-density lipoprotein cholesterol (LDL-C) and plays a key role in LDL-C transport and removal. Reduction in apoB synthesis is expected to reduce circulating LDL-C, a proven risk factor of cardiovascular disease. In the present study, we describe the outcome of the first-in-humans study on the safety and efficacy of an antisense oligonucleotide inhibitor of apoB.METHODS AND RESULTS:This study was a double-blind, randomized, placebo-controlled, dose-escalation investigation conducted at a single site in 36 volunteers with mild dyslipidemia. The study utilized an initial single dose of 50 to 400 mg of ISIS 301012, a 20-mer oligonucleotide, followed by a 4-week multiple-dosing regimen with the same assigned dose. Safety was assessed by the incidence, severity, and relationship of adverse events to dose. Efficacy was determined by changes in serum apoB and LDL-C relative to baseline and placebo. The most common adverse event was erythema at the injection site (21 of 29 subjects). ApoB was reduced by a maximum of 50% (P=0.002) from baseline in the 200-mg cohort. This decrease in apoB coincided with a maximum 35% reduction of LDL-C (P=0.001). LDL-C and apoB remained significantly below baseline (P<0.05) up to 3 months after the last dose.CONCLUSIONS:Administration of an antisense oligonucleotide to human apoB resulted in a significant, prolonged, and dose-dependent reduction in apoB and LDL-C. Although injection-site reactions were common, adherence to protocol was unaffected.

BACKGROUND:ISIS 113715 is a 20-mer phosphorothioate antisense oligonucleotide (ASO) that is complementary to the protein tyrosine phosphatase 1B (PTP-1B) messenger RNA and subsequently reduces translation of the PTP-1B protein, a negative regulator of insulin receptor. ISIS 113715 is currently being studied in early phase II clinical studies to determine its ability to improve or restore insulin receptor sensitivity in patients with type 2 diabetes mellitus. Future work will investigate the combination of ISIS 113715 with antidiabetic compounds.METHODS:In vitro ultrafiltration human plasma protein binding displacement studies and a phase I clinical study were used to characterise the potential for pharmacokinetic interaction of ISIS 113715 and three marketed oral antidiabetic agents. ISIS 113715 was co-incubated with glipizide and rosiglitazone in whole human plasma and tested for increased free drug concentrations. In a phase I clinical study, 23 healthy volunteers received a single oral dose of an antidiabetic compound (either metformin, glipizide or rosiglitazone) both alone and together with subcutaneous ISIS 113715 200 mg in a sequential crossover design. A comparative pharmacokinetic analysis was performed to determine if there were any effects that resulted from coadministration of ISIS 113715 with these antidiabetic compounds.RESULTS:In vitro human plasma protein binding displacement studies showed only minor effects on rosiglitazone and no effect on glipizide when co-incubated with ISIS 113715. The results of the phase I clinical study further indicate that there were no measurable changes in glipizide (5 mg), metformin (500 mg) or rosiglitazone (2 mg) exposure parameters, maximum plasma concentration and the area under the concentration-time curve, or pharmacokinetic parameter, elimination half-life when coadministered with ISIS 113715. Furthermore, there was no effect of ISIS 113715, administered in combination with metformin, on the urinary excretion of metformin. Conversely, there were no observed alterations in ISIS 113715 pharmacokinetics when administered in combination with any of the oral antidiabetic compounds.CONCLUSION:These data provide evidence that ISIS 113715 exhibits no clinically relevant pharmacokinetic interactions on the disposition and clearance of the oral antidiabetic drugs. The results of these studies support further study of ISIS 113715 in combination with antidiabetic compounds.

Purpose: A high placebo rate has been observed in previous IBD trials. Some have suggested that patients with mild baseline disease activity may increase the background “noise” and negatively impact the efficacy data. Positive data from two alicaforsen Phase 2 studies were recently presented, one placebo controlled and one with an active control, mesalamine (CS22). In the placebo controlled study (CS27), 112 subjects were randomized to compare 4 alicaforsen dose/schedules compared with placebo. Consistent with the CS22 results, CS27 study showed that 6 wks of 240mg alicaforsen qhs enema resulted in a durable clinical response that was statistically significant from placebo at Wks 18 and 30, (p = 0.04 and 0.03). To optimize the probability of success in Phase 3, we must understand the impact mild UC patients have on the efficacy data. Methods: Data from 44 subjects in the highest alicaforsen dose and placebo groups were reanalyzed to include only the subjects with moderate disease (DAI ≥ 7). Results: Eleven subjects met the criteria for moderate disease. Fig. A shows the high placebo response phenomenon commonly described in UC trials. Although the study demonstrated statistical difference at Wks 18 and 30, the study did not demonstrate a statistical difference at Wks 6 and 10 (p = 0.17 and 0.26). However, the placebo response was virtually eliminated when only patients with moderate disease were analyzed (Fig. B), without affecting the response curve of alicaforsen. Statistical difference was demonstrated at Wks 6 and 10 (both p = 0.05), even with a small number of patients. Conclusions: The sub-analysis confirms previous trial experience that inclusion of patients with mild baseline UC may significantly impact the placebo response rate and therefore has the potential to impact the outcome of the study. Careful consideration should be given in future studies to exclude patients with mild baseline disease activity. [figure 1]Figure

CSS is defined by asthma, allergic rhinitis and tissue eosinophilia. Gastrointestinal symptoms are common. The classic definition of CSS includes eosinophilic vasculitis. Since ICAM-1 modulates inflammatory cell trafficking and eosinophil activation, treatment with an antisense inhibitor of ICAM-1 should influence the disease. Case Study: The subject is a 52 yo woman with a history of asthma since her teens. Over the past several years, her asthma has worsened with asthma symptoms present most of the time despite aggressive medical management. Additionally, she suffers from allergic rhinitis and severe gastrointestinal symptoms including: abdominal pain, cramping, distention, nausea, vomiting, and diarrhea. High tissue eosinophils were present on intestinal biopsy. Despite aggressive medical management, she continues to have intermittently disabling pulmonary symptoms and virtually continuous gastrointestinal distention and pain. Therapeutic trials have included: prednisolone, Gastrocrom, Enterocort, 6-mercaptopurine (discontinued due to severe neutropenia), interferon-gamma, and methotrexate (transaminitis). After FDA and IRB approval, treatment was begun with 100 mg of ISIS 2302 (antisense to ICAM-1) as an initial IV infusion over 2 hours, then 300 mg IV over 2 hours three times a week for a total of 11 additional doses. At each visit, an interim history, a physical examination and laboratory studies were performed. Clinical endpoints were improvement in gastrointestinal (abdominal pain, cramping, abdominal distention, nausea and diarrhea) and systemic symptoms (fatigue, fever, pulmonary and nasal congestion) as defined by “patient global assessment” and “physician global assessment.” Routine pulmonary function tests were also done at baseline and at Week 2, 4, 8 and 16. Results: All gastrointestinal and systemic symptoms except myalgia and fatigue were rated as “complete relief or “marked improvement.” At week 4 (end of infusions) FEV had increased from prebronchodilator baseline of 3.47 to 3.98 liters and FEV1 from 2.39 to 2.69 liters and additional bronchodilator improvement could no longer be demonstrated. Conclusion: Antisense to ICAM-1 improved clinical and physiologic abnormalities of CSS suggesting an important role for ICAM-1 in eosinophil mediated diseases. Attention to the role of ICAM-1 in eosinophil mediated diseases may improve our understanding of mechanisms of disease.

s Submitted for the 68th Annual Scientific Meeting of the American College of Gastroenterology October 10-15, 2003, Baltimore, Maryland: INFLAMMATORY BOWEL DISEASE: PDF Only