1 Year Open-label Extension to CZOL446H2337 Safety and Efficacy Trial of Zoledronic Acid Twice Yearly in Osteoporotic Children Treated With Glucocorticoids

Key Inclusion criteria

Written informed consent before any study-related procedure.

Group 1:

• Children and adolescents, male or female, 6-19 years old, who met the inclusion criteria for entry into the Core study and who took at least one dose of study drug and have completed Visit 8 of the CZOL446H2337 Core study.
• Patient must be enrolled into the extension at Visit 9 up to 10 months after Visit 5 (month 6) of the Core study.
• Patients who followed the regimen of calcium and vitamin D intake as required in the Core study through diet or supplementation.

Group 2:

• Children and adolescents, male or female, 5 - 17 years old who met the inclusion criteria for entry into the Core study but were not enrolled because of clinically significant back pain from vertebral fracture and the preexisting clinical care at the Investigator site is to treat this type of patient with a bisphosphonate.
• Confirmed diagnosis of non-malignant conditions (including but not limited to rheumatic conditions, inflammatory bowel disease, Duchenne muscular dystrophy, nephrotic syndrome), treated with systemic glucocorticoids (i.v. or oral) within the 12 months preceding enrollment in the study (any duration)
• LS-BMD Z-score of -0.5 or worse confirmed by the central imaging vendor
• Evidence of at least 1 vertebral compression fracture (at least Genant Grade 1 vertebral compression or radiographic signs of vertebral compression) confirmed by central reading OR At least one lower OR 2 upper extremity long-bone, low-trauma, fracture which occurred sometime within the 2 years or preceding enrollment in the study, confirmed by radiological report. (*Low trauma fracture is defined as falling from standing height or less).

Key Exclusion criteria

• Major protocol violation in the Core Study (Group 1 only).
• Prior use of bisphosphonates (Group 2 only) or sodium fluoride (doses for osteoporosis not for dental hygiene).
• Hypocalcemia and hypophosphatemia: any value (age-matched) below the normal range at Visit 8 or 8A.
• Vitamin D deficiency (serum 25-hydroxy vitamin D concentrations of < 20 ng/mL or < 50 nmol/L) at Visit 8 (Group 1) or Visit 8A (Group 2).
• Renal impairment defined as an estimated glomerular filtration rate (GFR) < 60 mL/min/1.73 m2 at screening based on the Schwartz formula at Visit 8 or 8 A; a serum creatinine above the normal range at Visit 9 (Group 1) or an increase between Visit 8A and Visit 9 greater than 0.5 mg/dL (44.2 μmol/L) for Group 2.
• Female patients of child bearing potential are eligible only if they are not pregnant/non-lactating. Females of child bearing potential must be practicing a medically acceptable form of birth control for greater than 2 months prior to screening visit and consent to pregnancy tests during the study.