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.