An adverse event (AE) is any unfavorable and unintended sign (including a clinically significant abnormal laboratory finding, for example), symptom, or disease temporally associated with the study or use of investigational drug product, whether or not the AE is considered related to the investigational drug product. A TEAE is defined as an adverse event with an onset that occurs after receiving study drug. An SAE is any untoward medical occurrence that at any dose that results in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, leads to a congenital anomaly/birth defect, or is an important medical event. TEAEs considered related to the study drug as assessed by the Investigator are reported.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3.

Vital signs included blood pressure, heart rate, respiratory rate, and temperature. Only categories with at least one participant with event are reported.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3.

As prespecified in the protocol, percentage of participants with change from baseline in weight is reported in 2 categories, decrease of ≥7% from Baseline and increase of ≥7% from Baseline.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3. Overall number analyzed are the number of participants available for analyses.

Clinical laboratory tests included the analysis of chemistry, haematology, and urinalysis. Any value outside the normal range will be flagged for the attention of the investigator who will assess whether or not a flagged value is of clinical significance. Only those categories with at least one participant with event are reported. Normal range of creatinine clearance is 110 to 150 mL/min in males and 100 to 130 mL/min in females. Normal urine protein to creatinine (P/C) ratio= <0.2. Normal range for Alanine Aminotransferase (ALT) is 4 to 36 units per liter (U/L). Platelets normal range=140×10^9/L to 400×10^9/L.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3. Number analyzed is the number of participants with data available for analysis for the given category.

Normal QTcF at Baseline is defined as ≤450 milliseconds (ms) for males or ≤470 ms for females. Percentage of participants with QT interval outside of normal range are reported.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3.

A concomitant therapy was any non-protocol-specified drug or substance (including over-the counter medications, herbal medications, and vitamin supplements) administered between signing of informed consent and the final post-treatment visit for treating nervous and cardiovascular system disorders.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3.

SS included all enrolled participants who received at least 1 injection of inotersen in CS3. Overall number analyzed are the number of participants available for analyses. Number analyzed is the number of participants with data available for analysis at the given time point.

The mNIS+7 composite score is a measure of neurologic impairment that evaluates muscle weakness, sensation, reflexes, nerve conduction, and autonomic function. The mNIS+7 Composite Score has a range of -22.32 to 346.32 and a higher mNIS+7 composite score indicates worsening disease. A positive change from Baseline indicates worsening of polyneuropathy impairments. Mixed Effects Model with Repeated Measures (MMRM) was used for the analysis.

Full Analysis Set (FAS) included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk quality of life-diabetic neuropathy (QoL-DN) questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

Heart rate to deep breathing is a quantitative autonomic test using the CASE IV instrument that measures a participant's change in heart rate after deep breathing. The score of this component ranges from 0 to 3.72 points. Higher scores indicate impairment. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

The nerve conduction tests are quantitative tests that measure the conduction attributes of preselected nerves. The score range of this component is 0 to 18.6 points. Higher scores indicate impairment. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

The Heat-Pain Sensory test uses the CASE IV instrument to perform standardized psychophysical measurement to determine pain sensory thresholds in response to heat. The maximum score of this component is 0 to 40 points. Higher scores indicate impairment. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

The Touch-Pressure Sensory test uses the CASE IV instrument to perform standardized psychophysical measurement to determine pressure sensory thresholds in response to touch. The score range of this component is 0 to 40 points. Higher scores indicate impairment. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

The NIS score is a measure of neurologic impairment. The NIS Score has a range of 0 to 244 and a higher NIS score indicates lower function. A positive change from Baseline indicates worsening. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Overall number analyzed are the number of participants available for analyses.Number analyzed is the number of participants with data available for analysis at the given time point.

Cranial Nerve assessment involves testing 3rd and 6th nerves and facial, palate, and tongue weakness. The score range for this component is 0 to 40 points. Higher scores indicate worsening. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Overall number analyzed are the number of participants available for analyses. Number analyzed is the number of participants with data available for analysis at the given time point.

Muscle weakness involves testing 19 movements of muscles. The score range of this component is 0 to 152 points. Higher scores indicate worsening. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Overall number analyzed are the number of participants available for analyses. Number analyzed is the number of participants with data available for analysis at the given time point.

The Reflexes Score involves testing 5 reflexes to stimuli. The score range of this component is 0 to 20 points. Higher scores indicate worsening. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Overall number analyzed are the number of participants available for analyses. Number analyzed is the number of participants with data available for analysis at the given time point.

The Sensory Score is based on testing an index finger and a big toe each to 4 stimuli. The score of this component ranges from 0 to 32 points. Higher scores indicate impairment. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Overall number analyzed are the number of participants available for analyses. Number analyzed is the number of participants with data available for analysis at the given time point.

The Norfolk QoL-DN score is a measure of physical function/large fiber neuropathy, symptoms, activities of daily living, small fiber neuropathy, and autonomic neuropathy. The Norfolk QoL-DN total score has a range of -4 to 136, and a higher Norfolk QoL-DN score indicates poorer QoL. A positive change from Baseline indicates worsening in the QoL. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

The Norfolk QoL-DN physical functioning/large fiber neuropathy domain score is a sub-score of the total Norfolk QoL-DN Questionnaire. The Norfolk QoL-DN physical function/large fiber neuropathy domain score has a range of -4 to 56, and a higher Norfolk QoL-DN domain score indicates poorer quality of life (QoL). A positive change from Baseline indicates worsening in the QoL. MMRM was used for the analysis.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Overall number analyzed are the number of participants available for analyses. Number analyzed is the number of participants with data available for analysis at the given time point.

BMI=weight (kg)/[height (m)^2]. The mBMI is the BMI multiplied by the serum albumin (g/L).

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

BMI=weight (kg)/[height (m)^2].

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

PND score is defined as I = sensory disturbances in limbs without motor impairment; II = difficulty walking without the need of a walking aid; III = one stick or one crutch required for walking; IV = two sticks or two crutches needed. V = wheelchair required or patient confined to bed. The change from Baseline values have been categorized as: improved, not changed, worsened, and unknown. Percentage of participants with changes from Baseline are presented category-wise in this outcome measure. Only categories with at least one participant with event are reported.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point for the specified category.

GLS by ECHO is a measure of cardiac systolic function.

The Cardiomyopathy-echocardiogram (CM-ECHO) Set included the subset of the 420915-CS2 Randomized Set that had a diagnosis of transthyretin (TTR) cardiomyopathy at study entry of the parent study, but were not in the ECHO Subgroup in the parent study, plus participants who qualified to participate in the ECHO Subgroup (whether consented or not). Number analyzed is the number of participants with data available for analysis at the given time point.

GLS by ECHO is a measure of cardiac systolic function.

The Cardiomyopathy-echocardiogram (CM-ECHO) Set included the subset of the 420915-CS2 Randomized Set that had a diagnosis of transthyretin (TTR) cardiomyopathy at study entry of the parent study, but were not in the ECHO Subgroup in the parent study, plus participants who qualified to participate in the ECHO Subgroup (whether consented or not). Number analyzed is the number of participants with data available for analysis at the given time point.

Transthyretin protein concentration in serum was measured.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

RBP4 protein concentration in serum was measured.

FAS included all enrolled participants who received at least 1 injection of inotersen in this study (CS3) and who had at least 1 post-baseline efficacy assessment for the mNIS+7 score or Norfolk QoL-DN questionnaire total score collected after CS3 Study Day 1. Number analyzed is the number of participants with data available for analysis at the given time point.

CS3 Pharmacokinetic (PK) Set included all enrolled participants who received at least 1 dose of inotersen in CS3 and who had at least 1 evaluable PK sample collected and analyzed with reportable result in CS3. Number analyzed is the number of participants with data available for analyses at the given time point.