Melphalan, Peripheral Stem Cell Transplantation, and Interleukin-2 Followed by Interferon Alfa in Treating Patients With Advanced Multiple Myeloma

Inclusion Criteria: * Patient must be less than 70 years old * Patients with advanced Multiple Myeloma that meet the eligibility requirements for mobilization/debulking with Cytoxan/VP-16/G-CSF, Cytoxan/Taxol/G-CSF, or Cytoxan/G-CSF (according to protocol 506.03); if clinically indicated a lower dose of cytoxan than 4g/m2 may be used for mobilization based on the attending's discretion; also, if the patients had previously collected PBSC of sufficient number in the past and meet the other eligibility requirements, they may be entered on this study after approval by the PI * Patients with advanced Multiple Myeloma that have an identical syngeneic twin for donation of PBSCs * Patients have advanced Multiple Myeloma if they were diagnosed initially with stage II or III disease or had stage I disease that progressed after initial therapy or failed to respond to therapy * Syngeneic Donor Inclusion: * Donor and patient have adequate documentation that donor and recipient are syngeneic; including ABO typing, HLA typing and VNTR studies * Donor \> 20 kg * Donor meets eligibility to donate according to Standard Practice Guidelines Exclusion Criteria: * Patient's age \>= 70 * Karnofsky score less than 80 * A left ventricular ejection fraction less than 50%; Patients with congestive heart disease, history of myocardial infarction (MI), coronary artery disease or any arrhythmia history * Total bilirubin \> 1.5 mg/ml (unless history of Gilbert's disease) * Serum glutamic oxaloacetic transaminase (SGOT) or serum glutamic pyruvic transaminase (SGPT) \> 2 x upper limit of normal * Estimated creatinine clearance \< 60 ml/min or creatinine serum \> 2.0 mg/dl * Pregnancy * Seropositivity for human immunodeficiency virus * Patients who cannot give informed consent * Secondary malignancies other than basal cell carcinoma of the skin or carcinoma in situ within the last five years * History of seizures or requirement for medicines, such as haldol, for controlling mental disorders * Concurrent need for corticosteroid therapy * Active connective tissue disease * Pleural effusion, pericardial effusion or ascites * Patients allergic to gentamicin * Patients with positive PCR for hepatitis C or hepatitis B * Patients with hypersensitivity to E. coli - derived preparations * Patients with systemic infection at time of IL2 therapy * Patients who previously have had more than 50% of their pelvic area irradiated * Patients with pulmonary function tests that show diffusion capacity (corrected) \< 60%, and/or forced expiratory volume in 1 second (FEV1) \< 65% of predicted