Mass Accumulation Rate (MAR) as a Predictive Biomarker in Multiple Myeloma

Inclusion Criteria: 1. Written Informed Consent provided by patient 2. MM, with the following conditions: (CLOSED) \*For patients in the Vanguard cohort\* 1\. Treatment naïve disease with BM clinically indicated \*For patients in the RRMM cohort\* 1. Relapsed/refractory disease with BM samples clinically indicated 2. Within 4-weeks prior to initiation of 2nd-line or later therapy 3. Patient's oncologist must be planning to change the patient's next line of treatment to a monotherapy or combination therapy composed exclusively of drugs from the following list: Bortezomib (Velcade), Carfilzomib (Kyprolis), Lenalidomide (Revlimid), Pomalidomide (Pomalyst), Cyclophosphamide (Cytoxan), Dexamethasone, Ixazomib (Ninlaro), Venetoclax (Venclexta), Selinexor (Xpovio) Exclusion Criteria: 1. Unable or unwilling to provide informed consent 2. Daratumumab/Elotuzumab or other antibody-based therapeutic regimens as immediately planned treatment (as prior therapy is acceptable) 3. Patient enrolled/enrolling in a clinical trial where data or specimen sharing provisions preclude use in this study 4. Prior exposure to CAR-T therapy 5. Prior allogeneic stem cell transplant 6. Has received any systemic chemotherapy or RT, including palliative, within 7 days prior to BM biopsy 7. Has received any Ab therapy within 4 weeks prior to BM biopsy