Zoledronic Acid for the Prevention of Bone Loss Post-bone Marrow Transplantation for Thalassemia Major Patients

Inclusion Criteria: * Signed written informed consent. * Patients must be 18 years old and over. * Diagnosed with beta-thalassemia major * Scheduled for allogenic bone marrow transplantation * The date of randomization must be no more than 1 week after BMT. * Patients must be accessible for follow-up. * Life expectancy of at least 12 months from randomization. Exclusion Criteria: * Patients with any clinical or radiological evidence of existing fracture in the lumbar spine and/or total hip. * Patients with a history of fracture with low-density or no associated trauma. * Osteoporotic patients with T-score \<= -2.5 * Previous treatment with a bisphosphonate. * Patients with abnormal renal function as evidenced by either a serum creatinine determination 1.5 x or greater above the upper limit of normal or by a calculated creatinine clearance of 30 ml/minute or less. * Pregnancy and lactation. * Women of childbearing potential not on a medically recognized form of contraception. * Subjects who, in the opinion of the investigator, are unlikely to cooperate fully during the study. * Subjects participating simultaneously in studies with unapproved drugs, indications or treatment regimens. * Known hypersensitivity to zoledronic acid or bisphosphonates. * Patients with prior exposure to anabolic steroids, growth hormone, Parathyroid Hormone (PTH) or other drugs known to affect the skeleton (e.g., calcitonin, mithramycin, or gallium nitrate). * Serious intercurrent illness * History of metabolic bone diseases * History of corticosteroid treatment for other causes * History of antiepileptic drug treatment * History or surgery at the lumbosacral spine, with or without implantable devices. * Any disease of the spine that would preclude the proper acquisition of a lumbar spine DXA. * Mental illness that precludes the patient from giving informed consent. * Current active dental problems including infection of the teeth or jawbone (maxilla or mandibular); dental or fixture trauma, or a current or prior diagnosis of osteonecrosis of the jaw (ONJ), of exposed bone in the mouth, or of slow healing after dental procedures. * Recent (within 6 weeks) or planned dental or jaw surgery (e.g.. extraction, implants)