This study will test whether stopping maintenance therapy in people with multiple myeloma in MRD-negative remission has the same effect on disease control as continuing this therapy. The study will look at whether people currently on maintenance therapy can safely stop this treatment and continue with active surveillance instead while keeping their MRD-negative remission status for at least 1 year.

Inclusion Criteria:

• Patients with plasma cell myeloma treated with any number of prior lines of therapy, who at the time of study enrollment have had sustained MRD-negativity at a given timepoint and a subsequent time point with an interval of 3 or more years while on continuous maintenance therapy. MRD-negativity is defined per the International Myeloma Working Group Consensus Panel.
• MRD positivity will be defined by detection of 1 or more neoplastic plasma cells in 10^5 nucleated cells by flow cytometry as per IMWG criteria (i.e., sensitivity of 10-5)
• Age >/= 18 years with ECOG performance status \

This study will be conducted at MSKCC. Efforts will be made to ensure that women and minority groups are adequately represented in this trial. All patients will be seen by MSKCC myeloma physicians and associated MSKCC co-investigators, enrolled and registered at MSKCC.

Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.