A Research Study to Look Into How Semaglutide, Together With a Lower Dose of Insulin Glargine, Compares to a Higher Dose of Insulin Glargine Alone in People With Type 2 Diabetes (SUSTAIN OPTIMIZE)

Overview

This study compares semaglutide, together with a lower dose of insulin glargine, to a higher dose of insulin glargine in participants with type 2 diabetes. The study looks at how well the study medicines control blood glucose levels. Participants will either get semaglutide together with a lower dose of insulin glargine or a higher dose of insulin glargine. The study will last for about 47 weeks (approximately 11 months). Participants will have 9 clinic visits, 15 phone/video calls and 1 home visit. Participants will be asked to wear a sensor that measures their blood sugar all the time in 2 periods of 10 days during the study.

Eligibility

Inclusion Criteria:

• Diagnosed with Type 2 Diabetes Mellitus (T2D) mellitus greater than or equal to (>=) 180 days before screening.
• Glycated haemoglobin (HbA1c) of 7-10 percentage [(53-86 millimoles per mole (mmol/mol)] (both inclusive) as assessed by central laboratory on the day of screening.
• Body mass index (BMI) greater than or equal to (>=) 25 kilograms per meter square (kg/m^2) on the day of screening.
• Stable daily dose(s) greater than or equal to (>=) 90 days before screening of any of the following anti-diabetic drugs or combination regimens:
• Any metformin formulations greater than or equal to (>=) 1500 milligrams (mg) or maximum tolerated or effective dose.
• Any metformin combination formulation greater than or equal to (>=) 1500 mg or maximum tolerated or effective dose.

The treatment can be with or without sodium glucose cotransporter 2 (SGLT-2) inhibitors.

        • Treated with a once daily basal insulin (e.g. insulin glargine Unit 100 or U300, neutral
        protamine hagedorn (NPH) insulin, insulin detemir, insulin degludec) less than or equal to
        (<=) 40 units/day (U/day) for greater than or equal to (>=) 90 days before screening.
        Short-term bolus insulin treatment for a maximum of 14 days before screening is allowed.
        Exclusion Criteria:
          -  Uncontrolled and potentially unstable diabetic retinopathy or maculopathy. Verified by
             a fundus examination performed within the past 90 days before screening or in the
             period between screening and randomisation. Pharmacological pupil-dilation is a
             requirement unless using a digital fundus photography camera specified for non-dilated
             examination.
          -  Potentially missed diagnosis of Type 1 diabetes (T1D) or latent autoimmune diabetes in
             adults (LADA) verified by C-peptide less than 0.26 nanomoles per litre (nmol/L) (or
             260 picomoles per liter [pmol/L] [0.78 nanograms per millilitre {ng/mL}]) or
             antibodies to glutamic acid decarboxylase (anti-GAD) greater than 5 units/millilitre,
             as measured by the central laboratory at screening.
          -  Presence or history of pancreatitis (acute or chronic).
          -  Renal impairment measured as estimated Glomerular Filtration Rate (eGFR) value of less
             than 30 millilitre per minute per 1.73 meter square at screening as defined by Kidney
             Disease: Improving Global Outcomes (KDIGO) 2012 classification.
          -  Any episodes of diabetic ketoacidosis within 90 days before screening.
          -  Known hypoglycaemic unawareness as indicated by the investigator according to Clarke's
             questionnaire question 8.