Objectives: We performed a post-hoc analysis of clinical trial data with the goal of investigating whether diabetic subgroups identified by data-driven clustering respond differently to imeglimin. Methods: Data from randomized, double-blind clinical trials of imeglimin as monotherapy or add-on to insulin therapy were included in the analysis. For monotherapy, 1) duration of type 2 diabetes, 2) baseline BMI, 3) baseline HbA1c, and 4) baseline HOMA-β, and for add-on to insulin therapy, the first three and 4) insulin total daily dose were applied as coordinates to form clusters by the non-hierarchical k-means method. The efficacy of imeglimin were examined for each cluster. Results: We identified four clusters of patients with diabetes, which had significantly different patient characteristics. Cluster 1 was a group with lower values of all four indices compared to the total patient population before cluster segregation, cluster 2 was a group with longer duration of diabetes, cluster 3 was a group with higher baseline BMI and higher HOMA-β (for monotherapy) or higher insulin total daily dose (for add-on to insulin therapy), and cluster 4 was a group with higher baseline HbA1c. The improvement in HbA1c with imeglimin differed significantly among the four clusters. The mean change differences versus placebo for imeglimin in monotherapy ranged from -0.64% to -1.27%, and add-on to insulin therapy ranged from -0.31% to -0.82%. In all clusters except for cluster 3 in the add-on to insulin therapy, imeglimin showed statistically significant HbA1c improvement compared to placebo. Conclusion: Data-driven clustering of patients with type 2 diabetes allowed us to identify subgroups that respond differently to imeglimin in improving HbA1c. This new stratification might help to tailor and target the imeglimin treatment to patients who would benefit most. Disclosure K.Hagi: Employee; Sumitomo Pharma. K.Kochi: Employee; Sumitomo Dainippon Pharma Co., Ltd., Sumitomo Pharma Co., Ltd. H.Watada: Research Support; Boehringer Ingelheim Japan, Inc., Mitsubishi Tanabe Pharma Corporation, LifeScan Diabetes Institute, Eli Lilly Japan K.K., Sun Pharmaceutical Industries Ltd., Teijin Pharma Limited, Taisho Pharmaceutical Holdings Co., Ltd., Ono Pharmaceutical Co., Ltd., Kowa Company, Ltd., Merck Sharp & Dohme Corp., Sanwa Kagaku Kenkyusho, Speaker's Bureau; Mitsubishi Tanabe Pharma Corporation, Taiho Pharmaceutical Co. Ltd., Novo Nordisk, Abbott Japan Co., Ltd., Astellas Pharma Inc., Merck Sharp & Dohme Corp., Kissei Pharmaceutical Co., Ltd., AstraZeneca, Ono Pharmaceutical Co., Ltd., Boehringer Ingelheim Japan, Inc., Sanofi, Sun Pharmaceutical Industries Ltd., Eli Lilly Japan K.K. K.Kaku: Advisory Panel; Novo Nordisk, Consultant; Sanwa Kagaku Kenkyusho, Speaker's Bureau; Astellas Pharma Inc., Daiichi Sankyo, Eli Lilly Japan K.K., Boehringer Ingelheim Japan, Inc., Kowa Company, Ltd., Mitsubishi Tanabe Pharma Corporation, Taiho Pharmaceutical Co. Ltd., Takeda Pharmaceutical Co., Ltd. K.Ueki: Advisory Panel; Abbott Japan Co., Ltd., Research Support; Abbott Japan Co., Ltd., Boehringer Ingelheim Japan, Inc., Eli Lilly Japan K.K., Sumitomo Dainippon Pharma Co., Ltd., Novo Nordisk, Sanofi K.K., MSD Life Science Foundation, Takeda Pharmaceutical Co., Ltd., Speaker's Bureau; Boehringer Ingelheim Japan, Inc., Eli Lilly Japan K.K., Astellas Pharma Inc., AstraZeneca, Sumitomo Dainippon Pharma Co., Ltd., Novo Nordisk, Taiho Pharmaceutical Co. Ltd., Kowa Company, Ltd., Mitsubishi Tanabe Pharma Corporation, Ono Pharmaceutical Co., Ltd.