The real-world SPARTA Japan study confirmed the effectiveness and safety of the fixed-ratio combination of insulin glargine 100U/mL plus lixisenatide (iGlarLixi) once daily over 6months in Japanese people with type2 diabetes (T2D). This post hoc analysis examined the impact of participant characteristics on the achievement of age-defined glycaemic targets with iGlarLixi therapy. The retrospective, observational SPARTA Japan study included adults with T2D who initiated iGlarLixi. In this analysis, data from insulin-naïve and insulin-experienced participants were separately assessed to compare glycated haemoglobin (HbA1c), body weight and safety outcomes between those who achieved ('achieved' group) and those who did not achieve ('not-achieved' group) age-defined glycaemic targets after 6months of iGlarLixi. The not-achieved group was further stratified by whether or not their iGlarLixi dose was increased during treatment. In total, 418 participants were included in this analysis (138 insulin naïve and 280 insulin experienced). Among both insulin-naïve and insulin-experienced participants, those in the achieved group were older and had lower baseline HbA1c than those in the not-achieved group. Compared with the not-achieved group, the achieved group showed significantly greater HbA1c reductions from baseline (in both insulin-naïve and insulin-experienced participants) and significantly greater body weight reductions (in insulin-naïve participants), despite some participants in the not-achieved group receiving significantly higher insulin glargine doses than those in the achieved group. In both insulin-naïve and insulin-experienced participants, the incidence of hypoglycaemia and gastrointestinal-related adverse events was similar in the achieved and not-achieved groups. In a multivariate analysis, glycaemic target achievement was significantly more likely in older individuals and those who lost weight during iGlarLixi treatment. Achievement of age-defined glycaemic targets with iGlarLixi treatment for 6months was significantly affected by increased age and body weight loss, regardless of prior insulin exposure. UMIN-CTR Trials Registry, UMIN000044126; registered 10 May2021.