The primary objective is to analyze and compare the efficacy, the response rate, the CR and the response rate duration of both induction treatments and both maintenance treatments

A total of up to 260 patients > 65 years old diagnosed of Multiple Myeloma with symptomatic disease and that have not received previous chemotherapy for MM will be included.

Patients will be evaluated at scheduled visits in up to three study periods: Pre-treatment, Treatment and Follow up.

The Pre-treatment includes Screening and baseline visits. After providing informed consent, patients will be evaluated for study eligibility and then Patients will be randomized one to one to receive Melphalan+Prednisone+Velcade (Group A) or Thalidomide+Prednisone+Velcade (Group B). All of them will received the induction treatment up to 30 weeks. After 4 weeks, without progression and unacceptable toxicity, Patients will be again randomized one to one to receive maintenance treatment: Thalidomide+Velcade (Group M1) or Prednisone+Velcade (Group M2) during three years.

Once the treatment period has finished a follow up will be carry out. During this period we will evaluated response, progression-free survival and global survival every three months.

Inclusion Criteria:

• Must be able to comply with the protocol requirements.
• Must voluntary sign the informed consent before performance of any study-related procedure not part of normal medical care, with the understanding it can be withdrawn at any time without prejudice to future medical care.
• Age > 65 years.
• Patient recently diagnosed with symptomatic Multiple Myeloma based on standard criteria28 and that has not received any previous chemotherapy treatment for Multiple Myeloma Some steroid doses or bisphosphonates are allowed for emergencies before starting induction treatment.
• Patient has measurable disease, defined as follows:

For secretory multiple myeloma, measurable disease is defined as any quantifiable serum monoclonal protein value and, where applicable, urine light-chain excretion of ≥ 200 mg/24 hours.

• Patient has a ECOG performance status < 2
• Patient has a life-expectancy >3 months.
• Patient has the following laboratory values before beginning induction treatment:

Platelet count ≥ 50000/mm3, hemoglobin ≥ 8 g/dl and absolute neutrophil count ≥ 1000/mm3. Lower values are allowed if they are due to marrow infiltration.

Corrected serum calcium <14mg/dl. Aspartate transaminase (AST): ≤ 2.5 x the upper limit of normal. Alanine transaminase (ALT): ): ≤ 2.5 x the upper limit of normal. Total bilirubin: ≤1.5 x the upper limit of normal. Serum creatinine ≤ 2 mg/dl.

Exclusion Criteria:

• Patients previously received treatment to Multiple Myeloma, except steroids doses for urgency or bisphosphonates.
• Non-secretor Myeloma
• Patients with < Grade 2 peripheral neuropathy within 14 days before enrolment.
• Patient had major surgery within 4 weeks before enrolment.
• Patient has hypersensitivity to bortezomib, boron or mannitol.
• Patient has received other investigational drugs within 30 days before enrolment.
• Patient is known to be seropositive for the human immunodeficiency virus (HIV), Hepatitis B surface antigen-positive or active hepatitis C infection.
• Patient had a myocardial infarction within 6 months of enrollment or has New York Heart Association (NYHA) Class III or IV heart failure, uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or active conduction system abnormalities.
• Patient is enrolled in another clinical research study and/or is receiving an investigational agent for any reason.