Allo Transplant Followed by Lenalidomide and Sirolimus Maintenance in High-Risk Multiple Myeloma (MM)

Recipient Inclusion Criteria:

* 1\. Understand and voluntarily sign an informed consent form.
* 2\. Age 18-70 years at the time of signing the informed consent form.
* 3\. Able to adhere to the study visit schedule and other protocol requirements.
* 4\. Previously documented multiple myeloma (MM) with measurable monoclonal protein by either serum/urine protein electrophoresis or serum free light chains, or measurable plasmacytomas.
* 5\. ECOG performance status of 0-2 at study entry (see Appendix 2).
* 6\. Acceptable organ function as outlined in the protocol.
* 7\. Otherwise fitting institutional criteria for allogeneic stem cell transplantation.
* 8\. Presence of an HLA-matched (5/6 or 6/6 matched for HLA-A, B, and DR) sibling donor, or a HLA-matched (matched for at least HLA-A, B, C, and DRB1) unrelated donor by high-resolution testing.
* 9\. Disease free of prior malignancies for \>/= 5 years with exception of currently treated basal cell, squamous cell carcinoma of the skin, or carcinoma "insitu" of the cervix or breast.
* 10\. All study participants must be registered into the mandatory RevAssist® program, and be willing and able to comply with the requirements of RevAssist®.
* 11\. Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test

Recipient Exclusion Criteria:

* 1\. Any serious medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from signing the informed consent form.
* 2\. Pregnant or breast feeding females.
* 3\. Any condition, including the presence of laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study or confounds the ability to interpret data from the study.
* 4\. Known hypersensitivity to thalidomide or Lenalidomide.
* 5\. The development of erythema nodosum if characterized by a desquamating rash while taking thalidomide or similar drugs.
* 6\. Known seropositive for or active viral infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV). Patients who are seropositive because of hepatitis B virus vaccine or prior infection to which they are now immune (i.e., not carriers) are eligible.

Donor Inclusion Criteria:

The following categories of donor will be acceptable:

* 1\. HLA-matched related donor (5/6 or 6/6 match): Minimal typing necessary is serologic typing for class I (A, B) and molecular typing for class II (DRB1).
* 2\. HLA-matched Unrelated Donor (MUD): Molecular identity at least at HLA A, B, C, and DRB1 and DQB1 (8/10 match) by high resolution typing is required.
* 3\. Syngeneic donors are not eligible.
* 4\. The donor must be healthy and must be an acceptable donor as per institutional standards for marrow or stem cell donation.
* 5\. Age ≥ 18 years