A 20 yrs adult presents with severe hypoplastic anemia. Which of the following represent the most effective treatment?

Bone marrow transplantation from matched siblings after a preparative regimen of high dose cyclophosphamide and antithymocyte globulin can cure up to 90% of patients aged less than 40 years with severe aplastic anemia. Ref: Current Medical Diagnosis and Treatment, 2012, Chapter 13; Harrison's Principle of Internal Medicine, 18th Edition, Chapter 114