The ORR of the ICd group in ISS stages III, II, and I was 70.0%, 87.5%, and 100.0%, respectively, whereas the corresponding ORR of the Id group was 60.0%, 80.0%, and 100.0%. Meanwhile, patients in ISS stage III (65.0%) had lower ORR than those in stage II (84.6%) and I (100.0%) in both groups. Comparing the ORR of different stages in the two groups, it was not statistically significant (Table The mean age of the ICd group is 73.7 years, while that of the Id group was 76.2 years, and the median age of ICd group was 74 years, while that of the Id group was 77 years. There were 10 (52.6%) patients in the ICd group who were aged <75 years and only 6 (35.3%) patients in Id the group who were aged <75 years. Overall, patients in ICd seemed to be younger than those in the Id group, and the percentage of patients aged ≥75 years was higher in the Id group than in the ICd group. Age is quite an important prognostic factor of MM, so we analyzed whether the difference in efficacy of ICd and Id might be attributed to the younger population in the ICd group. It seemed that the ORR was higher in the ICd group (77.8%) than in the Id group (60%) when patients were ≥75 years old, and slightly lower in the ICd group (80%) than in the Id group (85.7%) when they were <75 years old. However, there was no significant difference (