Denosumab for Type 1 Diabetes

Main Inclusion Criteria * Age: Females 18-50 years; males 21-50 years (minimum age based on skeletal maturity) * Diagnosis of type 1 diabetes (T1D) based on ADA Criteria: * Hyperglycemia (glycosylated hemoglobin (HbA1c) ≥ 6.5%; OR * fasting plasma glucose ≥ 126 mg/dl (7.0 mmol/L); OR * 2-hour plasma glucose ≥ 200 mg/dL (11.1 mmol/L) during an oral glucose tolerance test; OR * In a patient with classic symptoms of hyperglycemia or hyperglycemic crisis, a random plasma glucose ≥ 200 mg/dl (11.1 mmol/L) * Documented history of at least one type 1 diabetes associated autoantibody * GAD specific autoantibodies (GADA); * Islet-antigen 2 specific autoantibody (IA-2A); and/or * Zinc Transporter 8 specific autoantibody (ZNT8A) * Time from T1D diagnosis to screening MMTT must be ≥ 12 months but ≤ 5 years * Non-fasting C-peptide concentrations of at least 0.2 nmol/L (0.6 ng/ml) at pre-screening and confirmed during a MMTT done at screening visit. * Serum calcium (corrected for albumin)\* within normal limits per site's local lab * Agreement by women of childbearing potential (WOCBP) and males of childbearing potential to use a highly effective method of birth control for the course of the study through at least 5 months from the last dose of protocol therapy Main Exclusion Criteria * History of delayed puberty unless there is radiologic evidence of skeletal maturity * Use of other investigational agents within 3 months of enrollment * Vitamin D3 deficiency (\< 30 ng/ml) * History of anorexia and/or eating disorder * BMI \> 32 kg/m2 * HbA1c \> 9.5% * Severe hypoglycemia or diabetic ketoacidosis (DKA) within 3 months prior to screening. Subjects who had such episodes within 3-6 months prior to screening, must have written clearance from their treating physician. * Use of any of the diabetes medications other than insulin within 3 months of enrollment (e.g., metformin, sulfonylurea, GLP-1 agonists, DPP4 inhibitors, Symlin, SGLT2-inhibitors, amylin) * Treatment with any of the following drugs in past year: immunosuppressants, anticonvulsant therapy, adrenal or anabolic steroids, calcitonin, selective estrogen receptor modulator, sodium fluoride (other than dental treatment), teriparatide, abaloparatide, strontium or aromatase inhibitors; any history of bisphosphonate treatment. * Bone fractures (excluding skull, facial bones, metacarpals, fingers, toes and spontaneous fractures associated with severe trauma) within the past 12 months * Disorders associated with altered skeletal structure or function (Paget's disease, chronic liver disease (liver enzymes \> twice the upper limit of normal), malignancy, hypoparathyroidism or hyperparathyroidism, acromegaly, Cushing's syndrome, hypopituitarism, chronic obstructive pulmonary disease, alcohol intake \> 3 units/day) * Significant dental/oral disease, including prior history or current evidence of osteonecrosis/osteomyelitis of the jaw, active dental or jaw condition requiring oral surgery, non-healed dental/oral surgery, or planned invasive dental procedures for the course of the study * Pregnancy or actively breastfeeding (within 6 months prior to screening), or planning to become pregnant with 5 months after last dose of protocol therapy