**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.**
Dr Matthew James Rees
Division of Hematology, Mayo Clinic
Rochester, MN, USA

**Main Body of the Abstract**
Introduction: Halting amyloid production, measured by hematological response (HR), and the degree of pre-existing renal damage, assessed by renal stage, are crucial to renal responses (RenRs) in AL amyloidosis. However, substantial variability in RenRs is unexplained by HR or renal stage. We investigated factors associated with deep and timely RenRs.
Method: Retrospective study of newly-diagnosed AL amyloidosis patients eligible for RenR between 2010-2022. RenRs were recorded at 6, 12, 24-months and the best RenR achieved. Multivariable logistic regression models for any RenR (≥RenPR) at 6-months and deep RenR (≥RenVGPR)at 12, 24-months and best response were created using best subset selection.
Results: 356 patients were included with a median age of 63-years (IQR:57-68) and median follow-up of 5.4-years. On univariate analysis, high dFLCs, kappa isotype, deep HR within 6-months and frontline stem-cell transplantation (ASCT) were significantly associated with an increased likelihood of any RenR at 6-months. High dFLCs, kappa isotype, ASCT, deep HR within 6-months and low renal stage were significantly associated with an increased likelihood of a deep RenR at 12 or 24-months. ASCT, a deep HR within 6-months and low renal stage were significantly associated with an increased likelihood of a deep RenR at best response. The multivariable model is shown, Table 1.
Discussion: HR and less advanced organ involvement are reliable indicators of timely and deep RenRs. In addition, transplantation, kappa isotype and high dFLCs predict RenR. The association between dFLCs and light-chain isotype with RenR implicates light-chain toxicity in organ damage and repair in AL amyloidosis.



**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.**
Dr Matthew James Rees
Division of Hematology, Mayo Clinic
Rochester, MN, USA

**Main Body of the Abstract**
**Introduction:** Halting amyloid production, measured by hematological response (HR), and the degree of pre-existing renal damage, assessed by renal stage, are crucial to renal responses (RenRs) in AL amyloidosis. However, substantial variability in RenRs is unexplained by HR or renal stage. We investigated factors associated with deep and timely RenRs.
**Method:** Retrospective study of newly-diagnosed AL amyloidosis patients eligible for RenR between 2010-2022. RenRs were recorded at 6, 12, 24-months and the best RenR achieved. Multivariable logistic regression models for any RenR (≥RenPR) at 6-months and deep RenR (≥RenVGPR)at 12, 24-months and best response were created using best subset selection.
**Results:** 356 patients were included with a median age of 63-years (IQR:57-68) and median follow-up of 5.4-years. On univariate analysis, high dFLCs, kappa isotype, deep HR within 6-months and frontline stem-cell transplantation (ASCT) were significantly associated with an increased likelihood of any RenR at 6-months. High dFLCs, kappa isotype, ASCT, deep HR within 6-months and low renal stage were significantly associated with an increased likelihood of a deep RenR at 12 or 24-months. ASCT, a deep HR within 6-months and low renal stage were significantly associated with an increased likelihood of a deep RenR at best response. The multivariable model is shown, Table 1.
**Discussion:** HR and less advanced organ involvement are reliable indicators of timely and deep RenRs. In addition, transplantation, kappa isotype and high dFLCs predict RenR. The association between dFLCs and light-chain isotype with RenR implicates light-chain toxicity in organ damage and repair in AL amyloidosis.



Predictors of timely and deep renal responses in AL amyloidosis PA124 (#361)

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.