Abstract: Objective  To investigate the predictive value of Frailty score for adverse reactions of ixazomib citrate in the treatment of multiple myeloma(MM). 
Methods  A total of 72 patients with MM were selected and treated with ixazomib citrate combined with thalidomide and dexamethasone (TD) regimen. The therapeutic effect and adverse reactions were observed. According to the degree of adverse reactions of patients, they were divided into grade Ⅰ-Ⅱ group and grade Ⅲ-Ⅳ group.The Frailty score was compared between two groups. Cox regression model was used to analyze the influencing factors of chemotherapy-related grade Ⅲ-Ⅳ adverse reactions. Receiver operating characteristic (ROC) curve model was used to analyze the predictive value of Frailty score for chemotherapy-related grade Ⅲ-Ⅳ adverse reactions. 
Results  All 72 MM patients were treated with ixazomib citrate, with a total effective rate of 80.55%; adverse reactions occurred in 70 cases, and fatigue accounted for the highest proportion, with an incidence rate of 72.22%, followed by lymphocyte reduction of 25.00% and anemia of 18.06%, and no adverse reactions occurred in 2 cases. The Frailty score of grade Ⅲ-Ⅳ group was higher than that of grade Ⅰ-Ⅱ group(P＜0.05). The 70 patients with adverse reactions were followed up for 12 months, and their average survival time was (22.30±2.28) months. Cox regression analysis showed that Frailty score ≥ 2 was the influencing factor of grade Ⅲ-Ⅳ adverse reactions in MM patients.ROC curve analysis showed that the Frailty score predicted chemotherapy-related grade Ⅲ-Ⅳ adverse reactions with an AUC value of 0.925(95%CI: 0.816-1.000, P＜0.001), a sensitivity of 88.90% and a specificity of 100.00%. 
Conclusion  Common adverse reactions during the treatment of MM patients with ixazomib citrate are fatigue, anemia, and thrombocytopenia. During treatment, the Frailty scoring system is used to evaluate adverse reactions, which is helpful for timely detection of those with high risk of adverse reactions and provides guidance for the adjustment of treatment plans.

Key words: multiple myeloma, ixazomib citrate, Frailty score