Hereditary transthyretin amyloidosis: baseline characteristics of patients in the NEURO-TTR trial

Background: Hereditary transthyretin (ATTRm) amyloidosis is a rare, progressive and fatal disease with a range of clinical manifestations.Objective: This study comprehensively evaluates disease characteristics in a large, diverse cohort of patients with ATTRm amyloidosis.Methods: Adult patients (N = 172) with Stage 1 or Stage 2 ATTRm amyloidosis who had polyneuropathy were screened and enrolled across 24 investigative sites and 10 countries in the NEURO-TTR trial (www.clinicaltrials.gov, NCT01737398). Medical and disease history, quality of life, laboratory data, and clinical assessments were analyzed.Results: The NEURO-TTR patient population was diverse in age, disease severity, TTR mutation, and organ involvement. Twenty-seven different TTR mutations were present, with Val30Met being the most common (52%). One third of patients reported early onset disease (before age 50) and the average duration of neuropathy symptoms was 5.3 years. Symptoms affected multiple organs and systems, with nearly 70% of patients exhibiting broad involvement of weakness, sensory loss, and autonomic disturbance. Over 60% of patients had cardiomyopathy, with highest prevalence in the United States (72%) and lowest in South America/Australasia (33%). Cardiac biomarker NT-proBNP correlated with left ventricular wall thickness (p<.001). Quality of life, measured by Norfolk QoL-DN and SF-36 patient-reported questionnaires, was significantly impaired and correlated with disease severity.Conclusions: Baseline data from the NEURO-TTR trial demonstrates ATTRm amyloidosis as a systemic disease with deficits in multiple organs and body systems, leading to decreased quality of life. We report concomitant presentation of polyneuropathy and cardiomyopathy in most patients, and early involvement of multiple body systems

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 .)

The Effects of 2′-O-Methoxyethyl Oligonucleotides on Renal Function in Humans

Systemically administered 2'-O-methoxyethyl (2'MOE) antisense oligonucleotides (ASOs) accumulate in the kidney and metabolites are cleared in urine. The effects of eleven 2'MOE ASOs on renal function were assessed in 2,435 patients from 32 phase 2 and phase 3 trials. The principle analysis was on data from 28 randomized placebo-controlled trials. Mean levels of renal parameters remained within normal ranges over time across dose groups. Patient-level meta-analyses demonstrated a significant difference between placebo-treated and 2'MOE ASO-treated patients at doses &gt;175 mg/week in the percentage and absolute change from baseline for serum creatinine and estimated glomerular filtration rate. However, these changes were not clinically significant or progressive. No dose-related effects were observed in the incidence of abnormal renal test results in the total population of patients, or subpopulation of diabetic patients or patients with renal dysfunction at baseline. The incidence of acute kidney injury [serum creatinine ≥0.3 mg/dL (26.5 μM) increases from baseline or ≥1.5 × baseline] in 2'MOE ASO-treated patients (2.4%) was not statistically different from placebo (1.7%, P = 0.411). In conclusion, in this database, encompassing 32 clinical trials and 11 different 2'MOE ASOs, we found no evidence of clinically significant renal dysfunction up to 52 weeks of randomized-controlled treatment

Suppressing transthyretin production in mice, monkeys and humans using 2nd-Generation antisense oligonucleotides

<p>Transthyretin amyloidosis (ATTR amyloidosis) is a rare disease that results from the deposition of misfolded transthyretin (TTR) protein from the plasma into tissues as amyloid fibrils, leading to polyneuropathy and cardiomyopathy. IONIS-TTR_Rx (ISIS 420915) is a 2nd-Generation 2′-<i>O</i>-(2-methoxyethyl) modified “2′-MOE” antisense oligonucleotide (ASO) that targets the TTR RNA transcript and reduces the levels of the TTR transcript through an RNaseH1 mechanism of action, leading to reductions in both mutant and wild-type TTR protein. The activity of IONIS-TTR_Rx to decrease TTR protein levels was studied in transgenic mice bearing the Ile84Ser human TTR mutant, in cynomolgus monkeys and in healthy human volunteers. Robust (>80%) reductions of plasma TTR protein were obtained in all three species treated with IONIS-TTR_Rx, which in mice and monkeys was associated with substantial reductions in hepatic TTR RNA levels. These effects were dose-dependent and lasted for weeks post-dosing. In a Phase 1 healthy volunteer study, treatment with IONIS-TTR_Rx for four weeks was well tolerated without any remarkable safety issues. TTR protein reductions up to 96% in plasma were observed. These nonclinical and clinical results support the ongoing Phase 3 development of IONIS-TTR_Rx in patients with ATTR amyloidosis.</p