Background: Elderly frail MM patients often lack evidence-based basis due to many comorbidities and poor treatment tolerance, and are often excluded by new drug clinical trials. There are many unsolved problems in clinical practice.There is still variation in the prognosis of frail patients identied using current frailty assessment tools. A potential treatment approach to improve outcomes in this heterogeneous population could involve starting with a well-tolerated low-intensity regimen and adjusting treatment based on ongoing dynamic frailty assessments.Therefore, our center conducted a retrospective study to explore the efcacy and safety of real-world isazomib-based two-drug regimen in the treatment of newly diagnosed elderly frail MM patients by adjusting treatment intensity based on dynamic frailty assessment. Methods: Patients with NDMM who received 2 or more courses of ixazomib-based regimens at the Department of Hematology, Afliated Hospital of Hebei University from January 1, 2018 to April 1, 2023.