A Study of Insulin Efsitora Alfa (LY3209590) Compared With Insulin Degludec in Participants With Type 2 Diabetes Currently Treated With Basal Insulin

Change From Baseline in Hemoglobin A1c (HbA1c) [Noninferiority]

Timeframe: Baseline, Week 26

HbA1c is the glycosylated fraction of hemoglobin A. HbA1c is measured to identify average plasma glucose concentration over prolonged periods of time. Least Squares (LS) Mean was determined using ANCOVA model with Baseline + Country + Type of Basal Insulin used at Baseline + Treatment (Type III sum of squares) as variables. Missing data at Week 26 were imputed by return-to-baseline multiple imputation approach.

Change From Baseline in Hemoglobin A1c (HbA1c) [Superiority]

Timeframe: Baseline, Week 26

HbA1c is the glycosylated fraction of hemoglobin A. HbA1c is measured to identify average plasma glucose concentration over prolonged periods of time. Least Squares (LS) Mean was determined using ANCOVA model with Baseline + Country + Type of Basal Insulin used at Baseline + Treatment (Type III sum of squares) as variables. Missing data at Week 26 were imputed by return-to-baseline multiple imputation approach.

Nocturnal Hypoglycemia Event Rate

Timeframe: Baseline up to Week 78

The event rate of participant-reported clinically significant glucose \<54 mg/dL (3.0 mmol/L) or severe nocturnal hypoglycemia that occurs at night and presumably during sleep between midnight and 6:00 AM), measured during treatment period up to week 78. Group mean is reported here. Group mean is determined by Negative Binomial Model using Number of episodes = Hemoglobin A1c at Baseline (%) + Treatment, with log (exposure in days/365.25) as an offset variable.

Percentage of Time in Glucose Range Between 70 and 180 mg/dL (3.9 and 10.0 mmol/L)

Timeframe: Week 22 to Week 26

Percentage of time in glucose range between 70 and 180 mg/dL (3.9 and 10.0 millimoles per liter (mmol/L)) inclusive measured by continued glucose monitoring (CGM) during CGM session prior to week 26. LS Mean was calculated using ANCOVA model with Baseline + Country + Hemoglobin A1c Stratum at Baseline + Type of Basal Insulin used at Baseline + Treatment (Type III sum of squares) as variables. Missing data during CGM session prior to Week 26 were imputed by return-to-baseline multiple imputation approach.

Change From Baseline in Fasting Glucose

Timeframe: Baseline, Week 26

Fasting glucose measured by Self-Monitoring of Blood Glucose (SMBG). LS Mean was determined using ANCOVA model with Baseline + Country + Type of Basal Insulin at Baseline + Baseline HbA1C Stratum (%) + Treatment (Type III sum of squares) as variables. Missing data at baseline are imputed with multiple imputation under assumption of missing at random. Missing data at Week 26 are imputed by return-to-baseline multiple imputation approach.

Weekly Insulin Dose at Week 26

Timeframe: Week 26

The average weekly insulin dose at Week 26 was reported. LS Mean was determined by mixed model repeated measures (MMRM) model using BASELINE + Country + Type of Basal Insulin at Baseline + Baseline HbA1C Stratum (%) + Treatment + Time + Treatment\*Time (Type III sum of squares) as variables. Variance-covariance structure was set as compound symmetry.

Hypoglycemia Event Rate

Timeframe: Baseline up to Week 78

Patient reported events of hypoglycemia - Hypoglycemia with glucose \<54 mg/dL (Level 2) or Severe Hypoglycemia (Level 3) was reported. A severe hypoglycemic event is characterized by altered mental or physical status requiring assistance of another person to actively administer carbohydrate, glucagon, or other resuscitative actions for the treatment of hypoglycemia. Group mean was reported and determined by Negative binomial method using Hemoglobin A1c at Baseline (%) + Treatment, with log (exposure in days/365.25) as variables.

Change From Baseline in Body Weight

Timeframe: Baseline, Week 78

Change from baseline in body weight was reported. LS Mean was determined by MMRM model using BASELINE + Treatment + Time + Treatment\*Time (Type III sum of squares) as variables.

Percentage of Time in Hypoglycemia Range

Timeframe: Week 22 to Week 26

Percentage of time in hypoglycemia range with glucose \<54 mg/dL (3.0 mmol/L) measured during CGM from 22-26 weeks. LS Mean was determined using ANCOVA model using Baseline + Country + Hemoglobin A1c Stratum at Baseline + Type of Basal Insulin used at Baseline + Treatment (Type III sum of squares) as variables. Missing data at baseline were imputed with multiple imputation under assumption of missing at random. Missing data at Week 22-26 were imputed by return-to-baseline multiple imputation approach.

Percentage of Time in Hyperglycemia Range

Timeframe: Week 22 to Week 26

Percentage of time in hyperglycemia range with glucose \>180 mg/dL (10.0 mmol/L) measured during the CGM session from 22-26 weeks. LS Mean was determined using ANCOVA model using Baseline + Country + Hemoglobin A1c Stratum at Baseline + Type of Basal Insulin used at Baseline + Treatment (Type III sum of squares) as variables. Missing data at baseline were imputed with multiple imputation under assumption of missing at random. Missing data at Week 22-26 were imputed by return-to-baseline multiple imputation approach.

Change From Baseline in Treatment-Related Impact Measure - Diabetes (TRIM-D)

Timeframe: Baseline, Week 26, Week 52, Week 78

The TRIM-D is a self-administered instrument, which assesses the impact of diabetes treatment on participants' functioning and well-being across available diabetes treatments. The TRIM-D consists of 28 items each assessed on a 5-point scale. TRIM-D items assess 5 domains of impact: * Treatment Burden (6 items) * Daily Life (5 items) * Diabetes Management (5 items) * Compliance (4 items), and * Psychological Health (8 items) Items within each domain are summed to obtain a raw domain score, which is then transformed to a 0-100 scale, where higher scores indicate a greater impact on participant's functioning and well-being. LS mean was determined using MMRM model with BASELINE + Country + Type of Basal Insulin at Baseline + Baseline HbA1C Stratum (%) + Treatment + Time + Treatment\*Time (Type III sum of squares) as variables.

Diabetes Treatment Satisfaction Questionnaire-Change Version (DTSQc) - Treatment Satisfaction Score: Week 26

Timeframe: Week 26

DTSQc treatment satisfaction score is a 6-item questionnaire which assesses relative change in overall treatment satisfaction. The treatment satisfaction score ranges from -18 to 18, where higher the score the greater the improvement in satisfaction with treatment. The lower the score the greater the deterioration in satisfaction with treatment.

Diabetes Treatment Satisfaction Questionnaire-Change Version (DTSQc) - Treatment Satisfaction Score: Week 52

Timeframe: Week 52

DTSQc treatment satisfaction score is a 6-item questionnaire which assesses relative change in overall treatment satisfaction. The treatment satisfaction score ranges from -18 to 18, where higher the score the greater the improvement in satisfaction with treatment. The lower the score the greater the deterioration in satisfaction with treatment.

Diabetes Treatment Satisfaction Questionnaire-Change Version (DTSQc) - Treatment Satisfaction Score: Week 78

Timeframe: Week 78

DTSQc treatment satisfaction score is a 6-item questionnaire which assesses relative change in overall treatment satisfaction. The treatment satisfaction score ranges from -18 to 18, where higher the score the greater the improvement in satisfaction with treatment. The lower the score the greater the deterioration in satisfaction with treatment.