Study Duration: The study period for each subject is expected to be 21 months. Subjects will receive up-to 4 cycles of IV infusion of Rituximab and Glucocorticoid. Maximum duration of treatment is expected to be 6 months. Subjects will complete scheduled visits not later than Study Month 21, thereafter they will enter into the long-term follow-up period. Subjects will be followed every 3 months for disease progression, initiation of subsequent leukemia treatment or survival.