**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Nicholas S Streicher
MedStar Health
Georgetown University School of Medicine
Washington, DC, USA

**Main Body of the Abstract**
Introduction: Transthyretin amyloidosis (ATTR) manifests as ATTR polyneuropathy (ATTR-PN), ATTR cardiomyopathy (ATTR-CM), or mixed phenotype. Tafamidis meglumine (20 mg) is approved in some markets to delay neurologic progression in ATTR-PN, while high-dose tafamidis (80/61 mg) is approved worldwide to reduce cardiovascular mortality and cardiovascular-related hospitalization in ATTR-CM. This study assessed the real-world benefit of high-dose tafamidis for delaying neurologic progression in mixed-phenotype variant ATTR-CM (ATTRv-CM).
Methods: This exploratory, retrospective, observational cohort study (NCT05139680) evaluated anonymized electronic medical records and included mixed-phenotype ATTRv-CM patients treated with high-dose tafamidis for >6 months. Neurologic assessments included the Medical Research Council (MRC) Scale for Muscle Strength, Neuropathy Impairment Score (NIS) muscle weakness subscale and Polyneuropathy Disability (PND) scale. Modified body mass index (mBMI) was also assessed.
Results: Patients (N = 10) started tafamidis treatment ~ 3.8 months after diagnosis and received treatment for ~ 20.8 months. Seven of 10 patients demonstrated normal muscle strength on MRC throughout the study, and 9 of 10 patients had no decline in muscle strength during the post-treatment period. The NIS muscle weakness subscale score was <60 for all patients at all time points, suggesting normal function to weak impairment. PND measured pre- vs post-assessment showed 6 of 10 patients had no change in walking capacity, while one-third showed improvement. mBMI remained relatively stable throughout the study.
Conclusions: This is the first real-world study demonstrating the value of high-dose tafamidis for delaying neurologic progression in mixed-phenotype ATTRv-CM. The findings underscore the importance of multidisciplinary assessment for ATTR amyloidosis patients.



Real-World Effectiveness of High-Dose Tafamidis on Neurologic Disease Progression in Mixed-Phenotype Variant Transthyretin Amyloid Cardiomyopathy PC94 (#15)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.