Inclusion Criteria:

Disease state:

- Age > 70 years newly diagnosed AML (including de novo, s-AML, t-AML)considered
ineligible for intensive treatment. Ineligibility for intensive treatment has to be
documented within the case report forms (Medical/Oncologic History).

- Age > 60 years relapsed/refractory AML in medically fit patients and newly diagnosed
AML (including de novo, s- AML,t-AML) in medically unfit patients

- Age 18-60 years: second or higher relapse of AML, not eligible for intensive therapy

- WBC <20x109/l, pretreatment with hydroxyurea is allowed to lower WBC

- Prior chemo-immunotherapy and other study-medications must have been completed 2
weeks before study treatment start. Treatment with hydroxyureas should be
discontinued 1 day before initiating dosing with lenalidomide

- Willingness and ability to comply with scheduled visits,treatment plan, laboratory
tests and other study procedures

- Females of childbearing potential (FCBP)† must agree to use two reliable forms of
contraception simultaneously or to practice complete abstinence from - FCBP must
have two negative pregnancy tests (sensitivity of at least 50 mIU/mL) prior to
starting study drug.

- Male subjects must agree to use a latex condom during sexual contact with females of
childbearing potential while participating in the study and for at least 28 days
following discontinuation from the study even if he has undergone a successful
vasectomy.

Exclusion Criteria:

- Acute promyelocytic leukemia [t(15;17)]

- bleeding disorder independent of the AML

- uncontrolled infection

- insufficiency of the kidneys (creatinin >1.5x upper normal serum level), of the liver
(bilirubin, AST or AP > 2x upper normal serum level)

- severe obstructive or restrictive ventilation disorder

- heart failure NYHA III/IV

- severe neurological or psychiatric disorder interfering with ability of giving an
informed consent

- no consent for registration, storage and processing of the individual
disease-characteristics and course

- peripheral neuropathy

- Performance status WHO > 2

- Presence of any medical/psychiatric condition or laboratory abnormalities which may
limit full compliance with the study, increase the risk associated with study
participation or study drug administration, or may interfere with the interpretation
of study results and, in the judgment of the Investigator, would make the patient
inappropriate for entry into this study

- Pregnancy or breast-feeding

- Known positive for HIV or infectious hepatitis, type A, B or C

- Known hypersensitivity to thalidomide

- Any prior use of lenalidomide

- Drug or alcohol abuse within the last 6 months

- Participating in other studies within the last 2 weeks