**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.**
Prefontaine, Amiee1, Mahe, Etienne1, McCulloch, Sylvia1, Tay, Jason1,2, Duggan, Peter1,2,  and Jimenez-Zepeda,Victor1,2,
1Tom Baker Cancer Center/University of Calgary
2Arnie Charbonneau Cancer Research Institute

**Main Body of the Abstract**
Background: The existence of patients with multiple myeloma (MM) and light-chain (AL) amyloidosis who present with a monoclonal gammopathy of undetermined significance (MGUS)-like phenotype has been recently reported with the aim of identifying a subgroup of patients with a better prognosis due to a more indolent course Methods: An algorithm to identify patients having MGUS-like phenotype was used as reported recently on the basis of the percentages of total bone marrow (BM) plasma cells (PC) and of clonal PC within the BM PC compartment, determined at diagnosis using flow cytometry in 120 patients with AL amyloidosis treated with bortezomib containing regimens (BCR) from  01/2012 to 01/2023. Results: Patients with AL amyloidosis and a MGUS-like phenotype had a better overall survival compared to patients with intermediate or Multiple Myeloma-like phenotype (Estimated of 119 months vs NR and 22 months, respectively, p=0.001) (Figure 1a). Further, Progression-Free survival was longer in the MGUS like phenotype group of patients compared to the intermediate and MM-like groups (NR versus 34 and 13 months, respectively, p=0.001) (Figure 1b). In a multivariate analysis, MGUS like phenotype, depth of response and less advanced staging correlated with better survival. Summary & Conclusion: We report here the role of MGUS-like phenotype for patients with AL amyloidosis treated with BCR at the Amyloidosis Program of Calgary. Our data validates the effect of MGUS like phenotype on survival in a consecutive treated group of AL amyloidosis cases.



**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.**
Prefontaine, Amiee_1_, Mahe, Etienne_1_, McCulloch, Sylvia_1_, Tay, Jason_1,2,_ Duggan, Peter_1,2,_  and Jimenez-Zepeda,Victor1,2,
**1**Tom Baker Cancer Center/University of Calgary
2Arnie Charbonneau Cancer Research Institute

**Main Body of the Abstract**
**Background**: The existence of patients with multiple myeloma (MM) and light-chain (AL) amyloidosis who present with a monoclonal gammopathy of undetermined significance (MGUS)-like phenotype has been recently reported with the aim of identifying a subgroup of patients with a better prognosis due to a more indolent course **Methods:** An algorithm to identify patients having MGUS-like phenotype was used as reported recently on the basis of the percentages of total bone marrow (BM) plasma cells (PC) and of clonal PC within the BM PC compartment, determined at diagnosis using flow cytometry in 120 patients with AL amyloidosis treated with bortezomib containing regimens (BCR) from  01/2012 to 01/2023. **Results:** Patients with AL amyloidosis and a MGUS-like phenotype had a better overall survival compared to patients with intermediate or Multiple Myeloma-like phenotype (Estimated of 119 months vs NR and 22 months, respectively, p=0.001) (**Figure 1a**). Further, Progression-Free survival was longer in the MGUS like phenotype group of patients compared to the intermediate and MM-like groups (NR versus 34 and 13 months, respectively, p=0.001) (**Figure 1b**). In a multivariate analysis, MGUS like phenotype, depth of response and less advanced staging correlated with better survival. **Summary & Conclusion**: We report here the role of MGUS-like phenotype for patients with AL amyloidosis treated with BCR at the Amyloidosis Program of Calgary. Our data validates the effect of MGUS like phenotype on survival in a consecutive treated group of AL amyloidosis cases.



Clinical significance of the Monoclonal Gammopathy of Undetermined Significance (MGUS) -like phenotype in patients with AL amyloidosis treated with Bortezomib-Containing Regimens (BCR) at the Amyloidosis Program of Calgary (APC) PA65 (#311)

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.