Combination Plerixafor (AMD3100)and Bortezomib in Relapsed or Relapsed/Refractory Multiple Myeloma

Inclusion Criteria:

* 18 years of age or older
* Must have received prior 1-5 therapies for their myeloma and have relapsed or refractory multiple myeloma. Prior therapy with bortezomib is allowed as long as they were not refractory to bortezomib
* Monoclonal protein serum of 1gm/dL or greater or monoclonal light chain in the urine protein electrophoresis of 200 mg/24 hours or greater, or measurable light chains by free light chain assay of 10 mg/dL or greater, or measurable plasmacytoma
* ECOG Performance Status 0, 1, or 2
* Laboratory values as outlined in the protocol

Exclusion Criteria:

* Uncontrolled infection
* Cytotoxic chemotherapy \< 3 weeks, or biologic or targeted novel therapy \< 2 weeks, or corticosteroids \< 2 weeks prior to registration. Patients may be receiving chronic corticosteroids if they are being given for disorders other than myeloma
* Pregnant women
* Nursing women
* Men or women of child-bearing potential who are unwilling to employ adequate contraception
* Other concurrent chemotherapy, immunotherapy, radiotherapy, or any ancillary therapy considered investigational
* Known to be HIV positive
* Radiation therapy \< 2 weeks prior to registration