Safety and Tolerability of GalNAc3-Conjugated Antisense Drugs Compared to the Same-Sequence 2'-O-Methoxyethyl-Modified Antisense Drugs: Results from an Integrated Assessment of Phase 1 Clinical Trial Data.

The triantennary N-acetylgalactosamine (GalNAc3) cluster has demonstrated the utility of receptor-mediated uptake of ligand-conjugated antisense drugs targeting RNA expressed by hepatocytes. GalNAc3-conjugated 2'-O-methoxyethyl (2'MOE) modified antisense oligonucleotides (ASOs) have demonstrated a higher potency than the unconjugated form to support lower doses for an equivalent pharmacological effect. We utilized the Ionis integrated safety database to compare four GalNAc3-conjugated and four same-sequence unconjugated 2'MOE ASOs. This assessment evaluated data from eight randomized placebo-controlled dose-ranging phase 1 studies involving 195 healthy volunteers (79 GalNAc3 ASO, 24 placebo; 71 ASO, 21 placebo). No safety signals were identified by the incidence of abnormal threshold values in clinical laboratory tests for either ASO group. However, there was a significant increase in mean alanine transaminase levels compared with placebo in the upper dose range of the unconjugated 2'MOE ASO group. The mean percentage of subcutaneous injections leading to local cutaneous reaction was 30-fold lower in the GalNAc3-conjugated ASO group compared with the unconjugated ASO group (0.9% vs. 28.6%), with no incidence of flu-like reactions (0.0% vs. 0.7%). Three subjects (4.2%) in the unconjugated ASO group discontinued dosing. An improvement in the overall safety and tolerability profile of GalNAc3-conjugated 2'MOE ASOs is evident in this comparison of short-term clinical data in healthy volunteers.

ISIS 449884 Injection Add-On to Metformin in Patients with Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled, Phase II Clinical Study.

INTRODUCTION: ISIS 449884, a 2'-O-methoxyethyl antisense oligonucleotide that targets the glucagon receptor (GCGR), has demonstrated an ability to reduce hepatic glucose output and lower the blood glucose level. The primary objective of this study was to investigate the safety and efficacy of ISIS 449884 as an add-on to metformin in a population of Chinese patients with type 2 diabetes mellitus (T2DM). METHOD: This was a multicenter, placebo-controlled (2:1), randomized, double-blind, parallel-enrollment, multiple-dose phase II study in Chinese patients with T2DM. A total of 90 patients who were uncontrolled by stable metformin monotherapy were randomized into three cohorts. Thirty subjects were enrolled in each cohort and received injections of ISIS 449884 (50 mg or 60 mg weekly or 100 mg every other week) or a corresponding volume of placebo (0.25 mL and 0.3 mL weekly or 0.5 mL every other week) subcutaneously in a 2:1 ratio for 16 weeks. RESULTS: The primary efficacy endpoint was analyzed in 88 subjects (ISIS 449884, n = 59; placebo, n = 29). The corrected LS mean change from baseline in glycated hemoglobin (HbA1c) at week 17 in the pooled ISIS 449884 treatment group was - 1.31% (95% CI - 1.66%, - 0.96%), and that in the pooled placebo group was 0.15% (95% CI - 0.37%, 0.66%). The LS mean difference between the two groups was - 1.46% (95% CI - 1.92%, - 1.00%, P < 0.001). Treatment-emergent adverse events (TEAEs) occurred in 53/60 subjects (88.3%) and 25/30 subjects (83.3%) in the pooled ISIS 449884 treatment group and the pooled placebo group, respectively, with similar incidences. Drug-related TEAEs occurred in 41/60 subjects (68.3%) and 9/30 subjects (30.0%), respectively. TEAEs of grade 3 or higher occurred in 5/60 (8.3%) subjects and 2/30 (6.7%) subjects, respectively, and none of them were drug related. CONCLUSIONS: The ISIS 449884 injection add-on to metformin significantly reduced HbA1c in patients with T2DM uncontrolled by stable metformin monotherapy and showed an acceptable benefit/risk profile. CLINICAL TRIAL REGISTRATION: www.chinadrugtrials.org.cn , CTR20191096.