The primary objective is to evaluate when Revlimid and Dexamethasone treatment extend the time to progression to symptomatic MM in patients with smoldering MM. The second one is to evaluate the efficacy of the treatment in response rate terms. Otherwise this study wants to evaluate the safety and tolerability of the treatment

A total of up to 120 patients diagnosed of smoldering Multiple Myeloma with high risk of progression to symptomatic MM will be included.

Patients will be stratified according its diagnosis date and randomized 1 to 1 to receive Revlimid and Dexamethasone (Group A) in 9 treatment cycles and maintenance with lower doses until progression or No treatment and observation until progression (Group B).

The 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 stratified and randomized (1:1) to Group A or Group B.

During Treatment Period patients will be evaluated once a month. Once the treatment period has finished a maintenance treatment with low doses of Revlimid and Dexamethasone will be carry out in Group A. During this period we will evaluate response, progression-free survival and global survival every two 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

• Age ≥ 18 years

• Patient recently diagnosed with smoldering Multiple Myeloma with high risk of progression to symptomatic Multiple Myeloma defined as follows:

  • Bone Marrow infiltration ≥ 10% CPs and M component Ig G ≥ 3 g/dl or Ig A ≥ 2 g/dl or Bence Jones Protein > 1 g/dl and absence of: hollowed out areas of bone, Hypercalcemia (Calcium-serum < 11.5 mg/dl), Renal Failure (creatinine < 2 mg/dl) and anaemia (Hb > 10 g/dl or at least 2g/dl under normal value.

  • Alternatively, patients with Bone Marrow infiltration with CPs ≥ 10 %, or Ig G ≥ 3 g/dl or Ig A ≥ 2 g/dl or Bence Jones Protein > 1 g/24h (but not the two of them together) and always without: lytic lesions, Hypercalcaemia, Renal Failure and Anaemia could be admitted with the following additional criteria:

    • % CPs abnormal (CPa/CpcMO) ≥ 95 % with immunodeficiency, defined as diminution of levels of one or two Immunoglobulins of more than 25% respect normal values.

• ECOG >= 2.

• The patient has to be able to complain with the protocol visits.

• Women of childbearing age must have a negative pregnancy test during the 14 days before first dose. And they must accept to use anticonceptive methods beginning during all the study until 4 weeks after the last one.

Exclusion Criteria:

• Any other organic or mental illness that could make impossible to sign the Inform consent.

• Patients previously received treatment to smoldering Multiple Myeloma.

• Pregnancy or breast-feed women

• Hollowed out areas of bone, anaemia, renal failure and Hypercalcemia

• The following laboratory data:

  • Absolute neutrophil count ≥ 1000/mm3
  • Platelet count ≥ 75000/mm3
  • Aspartate transaminase (AST) or Alanine transaminase (ALT ) ≤ 3 x the upper limit of normal.
  • Total bilirubin: ≤ 2 x the upper limit of normal.

• Patients with >= Grade 2 peripheral neuropathy within 14 days before enrolment.

• Patient with a previous clinical history of another malignant illness except for squamous cell carcinoma or skin cancer or cervical cancer except the patient could be free of symptoms during ≥ 5 years.

• Patient has hypersensitivity or adverse events previous to lenalidomide or Dexamethasone.

• Patient who has major surgery during the 4th weeks previous inclusion.

• Patient has received other investigational drugs within 30 days before enrolment.