Inclusion Criteria:

Phase I: For the first 10 patients:

- Patients with any haematological malignancy in > CR1 (first complete remission)

- Suitable related donor human leukocyte antigen (HLA)identical

- Age > 18 and < 70 years

For the 10 subsequent patients:

- Patients with any haematological malignancy candidates to receive an allogeneic
transplant

- Suitable related or unrelated donor (a maximum of 1 mismatched is allowed)

- Age > 18 and < 70 years phase II trial:

- High-risk multiple myeloma patients at first relapse / second complete remission
candidates to receive an allogeneic transplantation

- Age:> 18 < 70 years.

- Suitable donor, related or unrelated (a maximum of 1 mismatched is allowed)

- Measurable disease

- High risk first relapse is defined as:

- First early relapse after Autologous Stem Cell Transplant (ASCT)< 24 months

- First late relapses in case the patient does not achieve CR after second ASCT

- First relapse in patients with poor cytogenetic features

- All subjects must be able to comply with the Lenalidomide Pregnancy Prevention Risk
Management Plan.

Exclusion Criteria:

Any of the following:

- Prior severe comorbidity such as:

- Heart failure or previous infarction

- Uncontrolled Hypertension

- Arrhythmia

- Cirrhosis

- Peripheral neuropathy >Grade 2, 14 days prior to inclusion

- Psychiatric disease

- Prior history of other neoplasia except for carcinoma in situ in the last 10 years

- Hypersensitivity to Bz, Boric acid mannitol.

- Patients unable to use appropriate contraceptive methods

- Patients who have received an investigational drug 30 days prior to inclusion

- Positive human immunodeficiency virus (HIV) or active viral hepatitis

- Patients with pericardial disease

- Patients with acute diffuse infiltrative pulmonary disease

- Patients not willing to comply with the Lenalidomide Pregnancy Prevention Risk
Management Plan

- Patients not willing to receive thromboprophylaxis during the consolidation phase
will not be eligible.