Study to Evaluate Safety and Efficacy of Dapagliflozin and Saxagliptin in Patients With Type 2 Diabetes Mellitus Aged 10 to Below 18 Years Old

The purpose of this research study is to evaluate the efficacy and safety of the drugs dapagliflozin and saxagliptin in patients with Type 2 Diabetes who are aged 10 to below 18 years old and are currently taking metformin, insulin, or both drugs. Dapagliflozin and saxagliptin are both approved for use in patients with Type 2 Diabetes aged 18 years or older. Dapagliflozin (alone or in combination with other antidiabetic drugs) is available for use in adults in approximately 115 countries worldwide including the USA and Europe. Saxagliptin (alone or in combination with other antidiabetic drugs) is available for use in adults in approximately 100 countries worldwide. This study will assess how well dapagliflozin and saxagliptin work by finding out how these treatments affect blood glucose (sugar) levels compared to placebo (a pill that contains no active drug), in children and adolescents. Dapagliflozin and saxagliptin are considered investigational products in this study since while they have been approved for use in adults (patients 18 years or older), they haven't been approved for children and adolescents due to lack of clinical studies in this specific population. Patients with Type 2 Diabetes have higher levels of blood glucose (sugar) than patients who do not have this disease.The high level of sugar in the blood can lead to serious short-term and long-term medical problems. The main goal of treating diabetic patients is to lower blood glucose to a normal level. Lowering and controlling blood glucose help prevent or delay complications of diabetes, such as heart disease, kidney, eye and nerve diseases, and the possibility of amputation. Dapagliflozin is a drug that helps to reduce blood glucose levels by helping the kidneys to remove excess glucose from the blood and excrete it in the urine. It prevents the kidneys from returning glucose from the urine back into the bloodstream. Saxagliptin increases insulin production when blood glucose levels are high. Saxagliptin helps to improve blood sugar levels in response to a meal and between meals if blood glucose levels are not lowered effectively. Saxagliptin does not work when the blood glucose is low. Saxagliptin also helps to decrease the amount of sugar made by the body. Together, these processes reduce blood glucose levels and help to control Type 2 Diabetes. The subject will either receive one of the active study drugs or a placebo (a pill that looks identical but contains inactive drug). This study will be double blind; this means that neither the subject, nor the study doctor will know which treatment the subject will receive. Which treatment the subject receives is decided by a computer, purely by chance; this is called a "random assignment". For this study, there will first be a screening phase of up to 6 months if Investigator thinks that some of the screening tests can be repeated, followed by a 2 week lead in phase.Thereafter there will be a 26W short-term treatment phase (W1-26), and a 26 W long-term treatment phase (W27-52). Following this there will be a follow-up telephone call on week 56 and a post study visit at W104. At day1 visit after the lead in phase the subject will be randomly assigned to receive one of 3 treatments: dapagliflozin 5mg, saxagliptin 2.5mg or placebo in a blinded manner.This treatment will continue up to week 14. After week 14, the subject will be assigned to receive one of the following 5 treatments: dapagliflozin 5mg,dapagliflozin 10mg,saxagliptin 2.5 mg, saxagliptin 5 mg compared with placebo in a blinded manner. The drugs assigned after week 14 will be the same drugs as at Day 1, but some of the groups will receive them at a higher dose.Starting at W32 or W40, i.e., after the end of the primary endpoints, patients with background medication of metformin only, and an HbA1c value < 7.5% at W26 or W32, will undergo a third randomization. Eligible subjects from the treatment arms will undergo the randomized withdrawal of background medication, while eligible patients from the placebo arm will undergo, in addition to rand withdrawal of background medication a randomized switch to active treatment. Short/ long-term period study visits can be delayed by a maximum of 11 months in total. If the duration of IP administration is longer than 52(+1)weeks, the safety follow-up period should be shortened such that the complete study duration does not exceed 104 weeks(+7 days). A window period of -28 days to +7 days from the original scheduled date will be allowed for the Week-104 visit.If more than 12 weeks elapse between the HbA1c collection at W26 and the third rand at W32, or the HbA1c collection at W32 and the third rand at W40, the subject should not go through this rand as the HbA1c value would no longer be reliable to ascertain eligibility for the third rand