NCT05139680

A Study to Examine the Clinical Effectiveness of Tafamidis in Patients With Mixed Phenotype Hereditary Transthyretin Amyloidosis

Completed Results posted Last updated 19 September 2024

What this trial tests

trial testing tafamidis in Hereditary Transthyretin Amyloidosis (ATTRv) Cardiomyopathy (CM), Mixed Phenotype in 10 participants. Completed in 19 May 2023.

Timeline

8 March 2023

Primary endpoint
19 May 2023

19 May 2023

Quick facts

Lead sponsor	Pfizer
Status	Completed
Study type	OBSERVATIONAL
Enrollment	10
Start date	8 March 2023
Primary completion	19 May 2023
Estimated completion	19 May 2023
Sites	1 location across United States

Drugs / interventions tested

• tafamidis (Tafamidis) — full drug profile →

Conditions studied

• Hereditary Transthyretin Amyloidosis (ATTRv) Cardiomyopathy (CM), Mixed Phenotype — all drugs for Hereditary Transthyretin Amyloidosis (ATTRv) Cardiomyopathy (CM), Mixed Phenotype →

Sponsor

Pfizer — full company profile →

Who can join

18 and older, any sex, with Hereditary Transthyretin Amyloidosis (ATTRv) Cardiomyopathy (CM), Mixed Phenotype. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Neurologic Disease Progression: Number of Participants According to Muscle Weakness Assessment by Neuropathy Impairment Score (NIS) Subscale Score Primary · Pre-treatment baseline period to post-treatment period (data for specified duration was extracted from medical records and observed retrospectively in this study from 08-Mar-2023 to 19-May-2023)

Neurologic disease progression meant worsening of neurologic function over the time, is assessed by NIS subscale score in this outcome measure. NIS is a composite neurologic impairment score that assesses muscle weakness, sensation, and reflexes by physical exam. NIS subscale for muscle weakness assessment has a score range from 0 (minimum value) to 192 (maximum value). Lower scores indicates normal to mild impairment. Participants were classified as: no change, increase or decrease in NIS subscale scores from pre-treatment baseline period to post-treatment period. Pre-treatment baseline perio

Group	Value	95% CI
Tafamidis	2
Tafamidis	2
Tafamidis	3

Neurologic Disease Progression: Number of Participants According to Walking Capacity Assessment by Polyneuropathy Disability (PND) Score Primary · Pre-treatment baseline period to post-treatment period (data for specified duration was extracted from medical records and observed retrospectively in this study from 08-Mar-2023 to 19-May-2023)

Neurologic disease progression meant worsening of neurologic function over the time, is assessed by PND score in this outcome measure. PND is a scoring system to assess participants' walking capacity. It consists of four stages from stage 0 (no impairment) to stage IV (confined to a wheelchair or bedridden). Lower scores indicates normal to mild impairment. Participants were classified as: no change, increase or decrease in PND scores from pre-treatment to post -treatment period. Pre-treatment baseline period: at least 6 months and up to 12 months before treatment initiation. Post-treatment pe

Group	Value	95% CI
Tafamidis	6
Tafamidis	1
Tafamidis	3

Neurologic Disease Progression: Number of Participants According to Muscle Strength Assessment by Medical Research Council (MRC) Scale Primary · Pre-treatment baseline period to post-treatment period (data for specified duration was extracted from medical records and observed retrospectively in this study from 08-Mar-2023 to 19-May-2023)

Neurologic disease progression meant worsening of neurologic function over the time, is assessed by MRC scale in this outcome measure. MRC assessed muscle strength using a score of 0 (no contraction) to 5 (normal power), to grade the power of a particular muscle group in relation to the movement of a single joint. The higher scores mean a better outcome. Participants were classified as: no change, increase or decrease in MRC scale score from pre-treatment to post-treatment period. Pre-treatment baseline period: at least 6 months and up to 12 months before treatment initiation. Post-treatment p

Group	Value	95% CI
Tafamidis	8
Tafamidis	1
Tafamidis	1

Modified Body Mass Index (mBMI) Secondary · Pre-treatment baseline period, post-treatment period (data for specified duration was extracted from medical records and observed retrospectively in this study from 08-Mar-2023 to 19-May-2023)

mBMI was calculated as the product of BMI in kilogram per meter square (kg/m\^2) and serum albumin in gram per litre (g/L) to compensate for peripheral edema. Pre-treatment baseline period: at least 6 months and up to 12 months before treatment initiation. Post-treatment period: at least 6 months after treatment initiation with a +/- 3 months window.

Pre-Treatment

Group	Value	95% CI
Tafamidis	1001.06	± 269.52

Post-Treatment

Group	Value	95% CI
Tafamidis	1070.92	± 232.58

Sponsor's own description

This study will examine the clinical effectiveness of Tafamidis in patients with Mixed Phenotype Hereditary Transthyretin Amyloidosis using data that already exist in patients' medical records.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Real-World Effectiveness of High-Dose Tafamidis on Neurologic Disease Progression in Mixed-Phenotype Variant Transthyretin Amyloid Cardiomyopathy.
   Streicher N, Amass L, Wang R, Stephens JM, et al · · 2024 · cited 2× · PMID 38521883 · DOI 10.1007/s40119-024-00362-9