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.
Martha Grogan
Mayo Clinic, Rochester, MN, USA

Main Body of the Abstract
Background
Recent evidence has shown that many patients with ATTR amyloidosis develop a mixed phenotype of both polyneuropathy and cardiomyopathy, with polyneuropathy and musculoskeletal symptoms manifesting first, well before a confirmed diagnosis of cardiomyopathy. The objective of this study was to evaluate the occurrence of polyneuropathy and musculoskeletal manifestations prior to a confirmed diagnosis of ATTR amyloidosis with cardiomyopathy (ATTR-CM) in patients enrolled in APOLLO-B (NCT03997383).
Methods
Baseline disease characteristics and medical history, coded using Medical Dictionary for Regulatory Activities (MedDRA version 23.0), collected during the screening period from APOLLO-B were analyzed in the overall study population and in patients by ATTR amyloidosis type (hATTR, wtATTR) across both treatment arms. The event prevalence and time from event onset to diagnosis of ATTR amyloidosis with cardiomyopathy were summarized descriptively. Additional analyses of polyneuropathy and musculoskeletal manifestations in a matched cohort of patients, as a comparator group, are ongoing.
Results
Overall, medical histories of 359 ATTR-CM patients were analyzed, of which there were 71 hATTR and 288 wtATTR patients. Polyneuropathy and musculoskeletal manifestations were found in >20% and >60% of all patients, respectively, with these extra-cardiac events occurring at least 3 years prior to a confirmed diagnosis of ATTR-CM.
Conclusion
This analysis demonstrates that polyneuropathy and musculoskeletal manifestations may be early signs that are potentially overlooked in patients with ATTR-CM. Multisystem clinical assessment and early identification of non-cardiac manifestations are therefore crucial for management of this debilitating condition.

**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.**
Martha Grogan
Mayo Clinic, Rochester, MN, USA

**Main Body of the Abstract**
**Background**
Recent evidence has shown that many patients with ATTR amyloidosis develop a mixed phenotype of both polyneuropathy and cardiomyopathy, with polyneuropathy and musculoskeletal symptoms manifesting first, well before a confirmed diagnosis of cardiomyopathy. The objective of this study was to evaluate the occurrence of polyneuropathy and musculoskeletal manifestations prior to a confirmed diagnosis of ATTR amyloidosis with cardiomyopathy (ATTR-CM) in patients enrolled in APOLLO-B (NCT03997383).
**Methods**
Baseline disease characteristics and medical history, coded using Medical Dictionary for Regulatory Activities (MedDRA version 23.0), collected during the screening period from APOLLO-B were analyzed in the overall study population and in patients by ATTR amyloidosis type (hATTR, wtATTR) across both treatment arms. The event prevalence and time from event onset to diagnosis of ATTR amyloidosis with cardiomyopathy were summarized descriptively. Additional analyses of polyneuropathy and musculoskeletal manifestations in a matched cohort of patients, as a comparator group, are ongoing.
**Results**
Overall, medical histories of 359 ATTR-CM patients were analyzed, of which there were 71 hATTR and 288 wtATTR patients. Polyneuropathy and musculoskeletal manifestations were found in >20% and >60% of all patients, respectively, with these extra-cardiac events occurring at least 3 years prior to a confirmed diagnosis of ATTR-CM.
**Conclusion**
This analysis demonstrates that polyneuropathy and musculoskeletal manifestations may be early signs that are potentially overlooked in patients with ATTR-CM. Multisystem clinical assessment and early identification of non-cardiac manifestations are therefore crucial for management of this debilitating condition.

History of Polyneuropathy and Musculoskeletal Manifestations in Patients with Transthyretin-Mediated Amyloidosis with Cardiomyopathy in APOLLO-B PC108 (#176)

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.