The purpose of this study is to investigate the sensitivity and accuracy of non-invasive MRD assessment using liquid biopsy (blood draw) and functional imaging (whole body MRI) in participants with new diagnosed and previously treated multiple myeloma. The long-term goal of this study is to investigate whether non-invasive methods for MRD assessment can replace bone marrow aspiration and biopsy in a substantial percentage of participants with multiple myeloma.

There is an unmet clinical need for an easier, non-invasive, and reliable method to perform MRD assessments that can be used in clinical trials and routine practice. The two non-invasive modalities that are most promising for MRD assessment are liquid biopsy to detect circulating tumor cells (CTCs) and functional imaging to detect focal myeloma lesions. However, there are no prospective data on the sensitivity and specificity of non-invasive MRD assessment with respect to the gold standard of bone marrow sampling.

Inclusion Criteria:

• Adults age ≥18 years
• Patients with newly diagnosed multiple myeloma
• Patients with previously treated multiple myeloma with a maximum of two prior lines of therapy
• Expected life expectancy of greater than one year and intention to start a new line of treatment

Exclusion Criteria:

• Patients without cognitive capacity to give informed consent for participation
• Patients with contraindications to MRI, which include the following:
• Claustrophobia, which, at investigator's discretion, would prohibit patient from undergoing whole body diffusion-weighted magnetic resonance imaging (WB-DWI)
• Pacemaker
• Metallic implants, which would prohibit patient from undergoing MRI All subjects will be screened for any contraindication to MRI as per their guidelines at the time of patient enrollment.
• Patients must not receive granulocyte colony stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) injection within 1 week prior to WB-DWI.
• Patients must not have been initiated on treatment prior to baseline disease assessment by bone marrow aspiration/biopsy and/or WB-DWI Up to 160 mg of dexamethasone (or equivalent) and/or 1 dose of bortezomib (+/- Cyclophosphamide-Dexamethasone) is allowed prior to disease assessment by bone marrow aspiration and WB-DWI.

Patients with newly diagnosed or previously treated myeloma who are initiating a new line of therapy will be recruited.