**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.**
Authors: Fontana, Marianna1; Gillmore,     Julian1; Selvanayagam, Joseph2; Korczyk, Darius3;     Motorna, Olga4; Hillis, Graham5; Hare, James6;     Hanna, Mazen7; Drachman, Brian8; Masri, Ahmad9;     Sperry, Brett10; Singh, Vasvi11; Vaishnav, Joban12;     Sherman, Claire13; Bell, Gregory13; Meldorf, Matthew13
1University College of London, Royal Free Hospital;     2Flinders Medical Centre;3Princess Alexandra Hospital;     4Box Hill Hospital; 5Royal Perth Hospital; 6Alfred     Health; 7Cleveland Clinic,
8Univ of Pennsylvania, 9Oregon Health     Science University, 10St Luke’s Hospital, 11Midwest     Heart and Vascular, 12Johns Hopkins, 13Attralus, Inc

**Main Body of the Abstract**
Introduction:
Systemic amyloidosis (SA) is a progressive, debilitating and often fatal disease with a median life expectancy of two to five years in patients with cardiac involvement. Current therapies target the precursor protein leading slowing disease progression, but do not address the underlying amyloid deposits or improve cardiac function.  AT-02 is a humanized IgG1 monoclonal antibody with an amyloid binding peptide genetically fused to the light chain, mediating pan-amyloid binding to trigger macrophage-mediated phagocytosis. AT-02 is an investigational agent designed to remove amyloid deposits and improve cardiac function.
Trial Design:
The Phase 2 extension study will enroll SA patients who have completed the Phase 1 study. Participants may enter from the single ascending dose (SAD) or multiple dose (MD) portion of the Phase 1 study.  Patients from the MD portion of the phase 1 study must have AL or ATTR amyloidosis, with evidence of cardiac amyloid by cardiac magnetic resonance (CMR) and elevated NT-proBNP levels. Participants will be dosed every 4 weeks via IV infusion, at three dose levels, for up to two years. The primary objective of the study is to assess the safety and tolerability of  AT-02 in patients with SA. The secondary objectives are to assess 1) pharmacokinetics, 2) immunogenicity and 3) clinical activity of AT-02. The latter will be assessed by change from baseline in extracellular volume by CMR, structure and function using CMR and Echocardiography, NT-proBNP and troponin levels, NYHA functional classification, Kansas City Cardiomyopathy Questionnaire (KCCQ-23), and Six Minute Walk Test Distance (6MWT).



**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.**
**Authors:** Fontana, Marianna1; Gillmore,     Julian1; Selvanayagam, Joseph2; Korczyk, Darius3;     Motorna, Olga4; Hillis, Graham5; Hare, James6;     Hanna, Mazen7; Drachman, Brian8; Masri, Ahmad9;     Sperry, Brett10; Singh, Vasvi11; Vaishnav, Joban12;     Sherman, Claire13; Bell, Gregory13; Meldorf, Matthew13
1University College of London, Royal Free Hospital;     2Flinders Medical Centre;3Princess Alexandra Hospital;     4Box Hill Hospital; 5Royal Perth Hospital; 6Alfred     Health; 7Cleveland Clinic,
8Univ of Pennsylvania, 9Oregon Health     Science University, 10St Luke’s Hospital, 11Midwest     Heart and Vascular, 12Johns Hopkins, 13Attralus, Inc

**Main Body of the Abstract**
**Introduction**:
Systemic amyloidosis (SA) is a progressive, debilitating and often fatal disease with a median life expectancy of two to five years in patients with cardiac involvement. Current therapies target the precursor protein leading slowing disease progression, but do not address the underlying amyloid deposits or improve cardiac function.  AT-02 is a humanized IgG1 monoclonal antibody with an amyloid binding peptide genetically fused to the light chain, mediating pan-amyloid binding to trigger macrophage-mediated phagocytosis. AT-02 is an investigational agent designed to remove amyloid deposits and improve cardiac function.
**Trial Design:**
The Phase 2 extension study will enroll SA patients who have completed the Phase 1 study. Participants may enter from the single ascending dose (SAD) or multiple dose (MD) portion of the Phase 1 study.  Patients from the MD portion of the phase 1 study must have AL or ATTR amyloidosis, with evidence of cardiac amyloid by cardiac magnetic resonance (CMR) and elevated NT-proBNP levels. Participants will be dosed every 4 weeks via IV infusion, at three dose levels, for up to two years. The primary objective of the study is to assess the safety and tolerability of  AT-02 in patients with SA. The secondary objectives are to assess 1) pharmacokinetics, 2) immunogenicity and 3) clinical activity of AT-02. The latter will be assessed by change from baseline in extracellular volume by CMR, structure and function using CMR and Echocardiography, NT-proBNP and troponin levels, NYHA functional classification, Kansas City Cardiomyopathy Questionnaire (KCCQ-23), and Six Minute Walk Test Distance (6MWT).



Clinical Trial Design of AT-02 Phase 2 Open Label Extension Study in Systemic Amyloidosis PC143 (#519)

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.