A Study to Assess the Safety and Efficacy Of Tafamidis In Chinese Participants With Transthyretin Amyloid Cardiomyopathy (ATTR-CM)

An adverse event (AE) was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. All AEs that started after the first dosing but before the last dose plus the lag time (28 days) were TEAEs. A serious adverse event (SAE) was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience; persistent disability/incapacity; congenital anomaly/birth defect. A severe TEAE was an event that prevented normal everyday activities. Severe TEAEs were assessed by the investigator.

An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. All AEs that started after the first dosing but before the last dose plus the lag time (28 days) were TEAEs. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience; persistent disability/incapacity; congenital anomaly/birth defect. A severe TEAE was an event that prevented normal everyday activities. Severe TEAEs and treatment-related TEAEs were assessed by the investigator.

As a measure of functional capacity, the 6MWT measured the distance a participant could walk on a straight course in 6 minutes. 6MWT was conducted in accordance with guidelines established by the American Thoracic Society at Month 6 and Month 12 visits. Baseline was defined as the last measurement prior to first dose of study intervention.

Plasma NT-proBNP is a guideline-mandated biomarker in heart failure. Baseline was defined as the last measurement prior to the first dose of study treatment.

Blood sample of approximate 10 mL was collected at baseline, Months 1, 6, and 12 visits for measurement of TTR and TTR tetramer concentrations. TTR concentration was obtained prior to urea denaturation and TTR tetramer concentration was obtained after urea denaturation. Month 1 visit occurred 1 month post Day 1 +/- 1 week, Month 6 visit occurred 6 months post Day 1 +/- 2 weeks, and Month 12 visit occurred 12 months post Day 1 +/- 2 weeks or within 2 weeks after end of treatment. Responder was the participant who achieved TTR stabilization (ie, who had been TTR stabilized). Declaring a participant to have been (TTR) 'stabilized' was defined as the participant whose percent stabilization was equal to or greater than 32%. Percent stabilization (%) was calculated as ([fraction of initial {FOI} dosed - FOI baseline] / FOI baseline)×100, and FOI was calculated as average TTR tetramer concentration (post-denaturation) / average TTR concentration (pre-denaturation).

One K2EDTA blood sample of approximate 10 mL was collected on Day 1 (baseline), and at Months 1, 6, and 12 visits for measurement of TTR concentration. Month 1 visit occurred 1 month post Day 1 +/- 1 week, Month 6 visit occurred 6 months post Day 1 +/- 2 weeks, and Month 12 visit occurred 12 months post Day 1 +/- 2 weeks or within 2 weeks after end of treatment.

The KCCQ is a self-administered, 23-item questionnaire. KCCQ-OS scores are transformed to a 0 to 100 range, with lower scores denoting poorer quality of life.

The EQ-5D-5L is a brief, self-administered generic health status instrument. The instrument consists of 2 parts. In the first part, respondents are asked to rate their current health state on 5 dimensions (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) with each dimension having 5 levels of function (no problems, slight problems, moderate problems, severe problems, and extreme problems). The second part is a participant's self-rating of current health state on a Visual Analog Scale (EQ-5D VAS) with endpoints labeled 'best imaginable health state' (score of 100) and 'worst imaginable health state' (score of 0). The index values were calculated using the scoring algorithm based on preferences solicited from the Chinese population with 0 representing death and 1 representing full health. Higher EQ-5D-5L index value indicated a better quality of life. Change from baseline for EQ-5D-5L index values are reported for this outcome measure.

The EQ-5D-5L (5 levels version) is a brief, self-administered generic health status instrument. The instrument consists of 2 parts. In the first part, respondents are asked to rate their current health state on 5 dimensions (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) with each dimension having 3 levels of function (no problems, slight problems, moderate problems, severe problems and extreme problems). The second part is a participant's self-rating of current health state on a EQ-5D VAS with endpoints labeled 'best imaginable health state' (score of 100) and 'worst imaginable health state' (score of 0). The scores from the 5 dimensions may be used to calculate a single index value, also known as a utility score. EQ-5D VAS scores are reported for this outcome measure.

SF-12 is developed as a shorter alternative to the SF-36 for use in large-scale studies. It is an instrument with different weights for scoring physical and mental health, and measures health-related quality of life with 12 items categorized in eight areas: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health. This questionnaire was completed by the participant after the KCCQ and EQ-5D-5L, and prior to other required visit assessments. PCS score ranges from 0 to 100, and higher PCS score indicates a better quality of life. Change from baseline for PCS for SF-12 is reported for this outcome measure.

SF-12 is developed as a shorter alternative to the SF-36 for use in large-scale studies. It is an instrument with different weights for scoring physical and mental health, and measures health-related quality of life with 12 items categorized in eight areas: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health. This questionnaire was completed by the participant after the KCCQ and EQ-5D-5L, and prior to other required visit assessments. MCS score ranges from 0 to 100, and higher MCS score indicates a better quality of life. Change from baseline for MCS for SF-12 is reported for this outcome measure.

Blood samples of approximately 3 mL, to provide an approximately 1 mL plasma, were collected for measurement of plasma concentrations of tafamidis at Months 1, 6, and 12 visits. Month 1 visit occurred 1 month post Day 1 +/- 1 week, Month 6 visit occurred 6 months post Day 1 +/- 2 weeks, and Month 12 visit occurred 12 months post Day 1 +/- 2 weeks or within 2 weeks after end of treatment.