Bortezomib and Dexamethasone Followed by High-Dose Melphalan and Stem Cell Transplantation for Primary (AL) Amyloidosis

Inclusion Criteria: * Histological diagnosis of primary systemic (AL) amyloidosis based on: 1. Deposition of amyloid material by congo red stain showing characteristic green birefringence, and 2. monoclonal light chain protein in the serum or urine or immunohistochemical studies or serum free light chain assay and 3. evidence of tissue involvement other than carpal tunnel syndrome, i.e. positive immunohistochemical staining of bone marrow demonstrating clonal plasma cells; or tissue amyloid deposits with anti-kappa or anti-lambda anti-serum; evidence for a plasma cell dyscrasia (PCD) by serum/urine or bone marrow; or overwhelmingly convincing clinical features e.g. macroglossia, associated with other systemic manifestations. Note: Patients with senile, secondary, localized, dialysis-related or familial amyloidosis are not eligible. Confirmation of tissue diagnosis at all sites of organ dysfunction is encouraged, but not required. * Must be at least 18 years of age. * Must have a performance status of 0-2 by Southwest Oncology Group criteria * Must have left ventricular ejection fraction (LVEF) at least 45% by echocardiogram within 60 days of enrollment * Prior chemotherapy with alkylating agent allowed only if no evidence of Myelodysplastic Dysplastic Syndrome (MDS) morphologically or cytogenetically. Total cumulative dose of oral melphalan must be less than 300 mg. Patients should not have received any cytotoxic therapy less than 4 weeks prior to registration and should have fully recovered from the effects of such therapy. * Pulmonary Function Tests must show Diffusing capacity of the lungs for carbon monoxide (DLCO) at least 50%. * Voluntary written informed consent before performance of any study-related procedure not part of normal medical care, with the understanding that consent may be withdrawn by the subject at any time without prejudice to future medical care. * Female subject is either post-menopausal or surgically sterilized or willing to use an acceptable method of birth control (i.e., a hormonal contraceptive, intra-uterine device, diaphragm with spermicide, condom with spermicide, or abstinence) for the duration of the study. * Male subject agrees to use an acceptable method for contraception for the duration of the study. Exclusion Criteria: * No overt multiple myeloma (over 30% bone marrow plasmacytosis, extensive (great than 2) lytic lesions, hypercalcemia). * No other prior malignancy is allowed except for the following: adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, adequately treated Stage I or II cancer from which the patient is currently in complete remission, or any other cancer from which the patient has been disease-free for 3 years. * No known to be HIV positive. * No platelet count of less than or equal to 70,000 within 14 days before enrollment. * No absolute neutrophil count of less than or equal to 1000 within 14 days before enrollment. * No greater than or equal to Grade 2 peripheral neuropathy within 14 days before enrollment. * No myocardial infarction within 6 months prior to enrollment or has New York Heart Association (NYHA) Class III or IV heart failure (see section 8.4), uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or active conduction system abnormalities. Prior to study entry, any ECG abnormality at Screening has to be documented by the investigator as not medically relevant. * No hypersensitivity to bortezomib, boron or mannitol. * No pregnant or breast-feeding females. Confirmation that the subject is not pregnant must be established by a negative serum beta-human chorionic gonadotropin (beta-hCG) pregnancy test result obtained during screening. Pregnancy testing is not required for post-menopausal or surgically sterilized women. * Must not have received other investigational drugs with 14 days before enrollment * No serious medical or psychiatric illness likely to interfere with participation in this clinical study.