Inotersen Treatment for Patients with Hereditary Transthyretin Amyloidosis.

BACKGROUND: Hereditary transthyretin amyloidosis is caused by pathogenic single-nucleotide variants in the gene encoding transthyretin ( TTR) that induce transthyretin misfolding and systemic deposition of amyloid. Progressive amyloid accumulation leads to multiorgan dysfunction and death. Inotersen, a 2'- O-methoxyethyl-modified antisense oligonucleotide, inhibits hepatic production of transthyretin. METHODS: We conducted an international, randomized, double-blind, placebo-controlled, 15-month, phase 3 trial of inotersen in adults with stage 1 (patient is ambulatory) or stage 2 (patient is ambulatory with assistance) hereditary transthyretin amyloidosis with polyneuropathy. Patients were randomly assigned, in a 2:1 ratio, to receive weekly subcutaneous injections of inotersen (300 mg) or placebo. The primary end points were the change in the modified Neuropathy Impairment Score+7 (mNIS+7; range, -22.3 to 346.3, with higher scores indicating poorer function; minimal clinically meaningful change, 2 points) and the change in the score on the patient-reported Norfolk Quality of Life-Diabetic Neuropathy (QOL-DN) questionnaire (range, -4 to 136, with higher scores indicating poorer quality of life). A decrease in scores indicated improvement. RESULTS: A total of 172 patients (112 in the inotersen group and 60 in the placebo group) received at least one dose of a trial regimen, and 139 (81%) completed the intervention period. Both primary efficacy assessments favored inotersen: the difference in the least-squares mean change from baseline to week 66 between the two groups (inotersen minus placebo) was -19.7 points (95% confidence interval [CI], -26.4 to -13.0; P<0.001) for the mNIS+7 and -11.7 points (95% CI, -18.3 to -5.1; P<0.001) for the Norfolk QOL-DN score. These improvements were independent of disease stage, mutation type, or the presence of cardiomyopathy. There were five deaths in the inotersen group and none in the placebo group. The most frequent serious adverse events in the inotersen group were glomerulonephritis (in 3 patients [3%]) and thrombocytopenia (in 3 patients [3%]), with one death associated with one of the cases of grade 4 thrombocytopenia. Thereafter, all patients received enhanced monitoring. CONCLUSIONS: Inotersen improved the course of neurologic disease and quality of life in patients with hereditary transthyretin amyloidosis. Thrombocytopenia and glomerulonephritis were managed with enhanced monitoring. (Funded by Ionis Pharmaceuticals; NEURO-TTR ClinicalTrials.gov number, NCT01737398 .).

Cardiovascular and Metabolic Effects of ANGPTL3 Antisense Oligonucleotides.

BACKGROUND: Epidemiologic and genomewide association studies have linked loss-of-function variants in ANGPTL3, encoding angiopoietin-like 3, with low levels of plasma lipoproteins. METHODS: We evaluated antisense oligonucleotides (ASOs) targeting Angptl3 messenger RNA (mRNA) for effects on plasma lipid levels, triglyceride clearance, liver triglyceride content, insulin sensitivity, and atherosclerosis in mice. Subsequently, 44 human participants (with triglyceride levels of either 90 to 150 mg per deciliter [1.0 to 1.7 mmol per liter] or >150 mg per deciliter, depending on the dose group) were randomly assigned to receive subcutaneous injections of placebo or an antisense oligonucleotide targeting ANGPTL3 mRNA in a single dose (20, 40, or 80 mg) or multiple doses (10, 20, 40, or 60 mg per week for 6 weeks). The main end points were safety, side-effect profile, pharmacokinetic and pharmacodynamic measures, and changes in levels of lipids and lipoproteins. RESULTS: The treated mice had dose-dependent reductions in levels of hepatic Angptl3 mRNA, Angptl3 protein, triglycerides, and low-density lipoprotein (LDL) cholesterol, as well as reductions in liver triglyceride content and atherosclerosis progression and increases in insulin sensitivity. After 6 weeks of treatment, persons in the multiple-dose groups had reductions in levels of ANGPTL3 protein (reductions of 46.6 to 84.5% from baseline, P<0.01 for all doses vs. placebo) and in levels of triglycerides (reductions of 33.2 to 63.1%), LDL cholesterol (1.3 to 32.9%), very-low-density lipoprotein cholesterol (27.9 to 60.0%), non-high-density lipoprotein cholesterol (10.0 to 36.6%), apolipoprotein B (3.4 to 25.7%), and apolipoprotein C-III (18.9 to 58.8%). Three participants who received the antisense oligonucleotide and three who received placebo reported dizziness or headache. There were no serious adverse events. CONCLUSIONS: Oligonucleotides targeting mouse Angptl3 retarded the progression of atherosclerosis and reduced levels of atherogenic lipoproteins in mice. Use of the same strategy to target human ANGPTL3 reduced levels of atherogenic lipoproteins in humans. (Funded by Ionis Pharmaceuticals; ClinicalTrials.gov number, NCT02709850 .).

Missing data in clinical trials for weight management.

In 2014, the US FDA approved liraglutide for weight management. The statistical review of the application presented various challenges related to the handling of missing data. The ability of the drug to cause weight loss was not in question. The challenge centered on obtaining a reliable estimate of the intention-to-treat effect to support the risk-benefit evaluation. Subjects in the trials that stopped treatment prior to the endpoint were encouraged to attend the primary endpoint visit. Data from the subjects that returned for a primary efficacy assessment played a significant role in the statistical review. They were used to illustrate shortcomings of the applicant's primary efficacy analysis and sensitivity analyses. They were also used in the FDA analyses to address missing data. The goal of this article is to illustrate challenges and considerations associated with the handling of missing data in clinical trials.

Bayesian approach for clinical trial safety data using an Ising prior.

In drug safety, development of statistical methods for multiplicity adjustments has exploited potential relationships among adverse events (AEs) according to underlying medical features. Due to the coarseness of the biological features used to group AEs together, which serves as the basis for the adjustment, it is possible that a single adverse event can be simultaneously described by multiple biological features. However, existing methods are limited in that they are not structurally flexible enough to accurately exploit this multi-dimensional characteristic of an adverse event. In order to preserve the complex dependencies present in clinical safety data, a Bayesian approach for modeling the risk differentials of the AEs between the treatment and comparator arms is proposed which provides a more appropriate clinical description of the drug's safety profile. The proposed procedure uses an Ising prior to unite medically related AEs. The proposed method and an existing Bayesian method are applied to a clinical dataset, and the signals from the two methods are presented. Results from a small simulation study are also presented.

Testing a noninferiority hypothesis: what to anticipate when the adverse event is rare.

While randomized controlled trials may not be considered efficient for investigating rare adverse events based on their size, biases associated with other epidemiological designs may justify the additional resources. In certain contexts it may be appropriate, for example, to inflate the noninferiority (NI) margin to decrease the sample size, provided the excess risk that will be ruled out remains clinically relevant. The implication of a reduced sample size on the number of events anticipated from the trial is often not considered at the study design phase but may have important ramifications. To assess the implications of modifying study design parameters, approximations are presented for (a) how likely it is that no events will be observed, (b) how many events should be anticipated, and (c) how likely it is that v or more events will be observed. The approximations presented are intended to serve as tangible a priori expectations from the study. This work is motivated from an FDA Advisory Committee meeting regarding a discussion at the association between long-acting beta-agonists and asthma-related deaths.

The Effects of 2'-O-Methoxyethyl Containing Antisense Oligonucleotides on Platelets in Human Clinical Trials.

A thorough analysis of clinical trial data in the Ionis integrated safety database (ISDB) was performed to determine if there is a class effect on platelet numbers and function in subjects treated with 2'-O-methoxyethyl (2'MOE)-modified antisense oligonucleotides (ASOs). The Ionis ISDB includes over 2,600 human subjects treated with 16 different 2'MOE ASOs in placebo-controlled and open-label clinical trials over a range of doses up to 624 mg/week and treatment durations as long as 4.6 years. This analysis showed that there is no class generic effect on platelet numbers and no incidence of confirmed platelet levels below 50 K/µL in subjects treated with 2'MOE ASOs. Only 7 of 2,638 (0.3%) subjects treated with a 2'MOE ASO experienced a confirmed postbaseline (BSLN) platelet count between 100 and 50 K/µL. Three of sixteen 2'MOE ASOs had >10% incidence of platelet decreases >30% from BSLN, suggesting that certain sequences may associate with clinically insignificant platelet declines. Further to these results, we found no evidence that 2'MOE ASOs alter platelet function, as measured by the lack of clinically relevant bleeding in the presence or absence of other drugs that alter platelet function and/or number and by the results from trials conducted with the factor XI (FXI) ASO.

Age and risks of FDA-approved long-acting ß2-adrenergic receptor agonists.

OBJECTIVE: To determine the risk, by age group, of serious asthma-related events with long-acting ß(2)-adrenergic receptor agonists marketed in the United States for asthma. METHODS: The US Food and Drug Administration performed a meta-analysis of controlled clinical trials comparing the risk of LABA use with no LABA use for patients 4 to 11, 12 to 17, 18 to 64, and older than 64 years old. The effects of age on a composite of asthma-related deaths, intubations, and hospitalizations (asthma composite index) and the effects of concomitant inhaled corticosteroid (ICS) use were analyzed. RESULTS: One hundred ten trials with 60 954 patients were included in the meta-analysis. The composite event incidence difference for all ages was 6.3 events per 1000 patient-years (95% confidence interval [CI]: 2.2-10.3) for using LABAs compared with not using LABAs. The largest incidence difference was observed for the 4- to 11-year age group (30.4 events per 1000 patient-years [95% CI: 5.7-55.1]). Differences according to age were statistically significant (P = .020). Results for the subgroup of patients with concomitant ICS use (n = 36 210) were similar to the overall results; with assigned ICSs (n = 15 192), the incidence difference was 0.4 events per 1000 patient-years (95% CI: -3.8 to 4.6), and there was no statistically significant difference according to age group. CONCLUSIONS: The excess of serious asthma-related events attributable to LABAs was greatest among children. Additional data are needed to assess risks of LABA use for children with simultaneous ICS use.