Vacc-4x + Lenalidomide vs. Vacc-4x +Placebo in HIV-1-infected Subjects on Antiretroviral Therapy (ART)

Inclusion Criteria: 1. Men, age ≥ 18 and ≤ 55 years at the time of screening. 2. Women, age ≥ 50 and ≤ 55 years at the time of screening, who are not of childbearing potential (see Exclusion criteria, point 9). Childbearing status must be documented. 3. Clinically stable on ART for the last 18 months (changes in therapy are allowed as long as the viral load is stable). 4. Well controlled with no treatment failure due to ART resistance in the past 5. Screening plasma viral load (HIV-1 RNA) less than 50 copies/mL for the last six months. If screening value is between 50-500 copies/mL rescreening is allowed. Single blips (up to 500 copies/mL) are allowed. 6. Screening CD4 cell count ≥ 200x10\^6 cells/L and ≤500x10\^6 cells/L. (Rescreening is allowed) 7. Laboratory test results within these ranges: Absolute neutrophil count (ANC) \>1.0x10\^9 /L, Platelet count \>75x10\^9 /L and eGRF (MDRD) \>60 mL/min 8. Signed informed consent 9. Willingness to adhere to Global Pregnancy Prevention Risk Management Plan Lenalidomide Exclusion Criteria: 1. Reported pre-study AIDS-defining illness within the previous year 2. Malignant disease. 3. On chronic treatment with immunosuppressive therapy. 4. Autoimmune disorders, present or in the past if there is an increased risk of disease exacerbation. 5. Unacceptable values of the hematologic and clinical chemistry parameters (including those associated with hemophilia), as judged by the Investigator or the Sponsor (or designee), including creatinine values \>1.5x upper limit of normal (ULN), and AST (SGOT), ALT (SGPT), and alkaline phosphatase values \>2.5x ULN. 6. Concurrent chronic active infection such as viral hepatitis B or C or tuberculosis. 7. Previous thromboembolic events or patient is currently immobilized 8. Sexually active subjects who do not adhere to Global Pregnancy Prevention Risk Management Plan Lenalidomide 9. Current participation in other clinical therapeutic studies. 10. Females of childbearing potential will be excluded from this trial. A female of childbearing potential (FCBP) is a sexually mature female who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal (amenorrhea following cancer therapy does not rule out childbearing potential) for at least 24 consecutive months (i.e. has had menses at any time in the preceding 24 consecutive months). 11. The development of erythema nodosum if characterized by a desquamating rash while previously 12. Incapability of compliance to the treatment protocol, in the opinion of the Investigator.