Patients undergo blood and bone marrow collection periodically for pharmacokinetic, pharmacodynamic, and immunological studies. Samples are analyzed for the presence of antibodies and proteins via ELISA; CD3, CD4, and CD8 T cell counts, CD127, Ki-67, and Bcl-2 expression in CD4+ and CD8+ T cells, and CD19 B cell counts via flow cytometry; and clonal B cell proliferation via PCR and flow cytometry.