Elranatamab in Relapsed/Refractory Multiple Myeloma

Inclusion Criteria:

1. Provision of signed and dated informed consent form

2. Stated willingness to comply with all study procedures and availability for theduration of the study

3. Prior diagnosis of relapsed/refractory MM and have received 1 to 3 prior lines oftherapy as defined by the IMWG criteria (Rajkumar et al., 2014) including anti-CD38monoclonal antibody, proteosome inhibitor (PI), and immunomodulatory drug (IMiD),and BCMA-directed chimeric antigen receptor T-cell (CAR T-cell) therapy

4. Refractory is defined as having disease progression while on therapy or within 60 days of last dose in any line, regardless of response.

5. If participant has not received BCMA-directed CAR T-cell therapy, must beineligible for CAR T-cell therapy or deferred such treatment by participant

6. Aged greater or equal to 18 years

7. Measurable disease as defined by any of the following:

8. Serum M-protein level ≥ 0.5 g/dL by serum protein electrophoresis (SPEP), or

9. Urine M-protein ≥ 200mg/24 hours by urine protein electrophoresis (UPEP), or

10. Involved serum free light chain ≥ 10 mg/dL (≥100mg/L) AND an abnormal serumfree light chain ratio in patients without measurable disease in the serum orurine

11. Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2

12. Adequate hematological function defined as

13. Absolute neutrophil count (ANC) ≥1,000/mm3 (G-CSF not permitted for at least 1week prior to the first dose of elranatamab)

14. Hemoglobin ≥8.0 g/dL (transfusion support is permitted if completed at least 1week prior to planned start of dosing)

15. Platelet count ≥75,000/mm3 or ≥50,000/mm3 if >50% involvement with plasma cellsin the screening bone marrow (transfusion support is permitted if completed atleast 1 week prior to planned start of dosing)

16. Adequate renal function with estimated creatinine clearance (CrCl) ≥30 mL/min ascalculated using Cockcroft-Gault equation.

17. Adequate liver function defined as

18. Aspartate and alanine aminotransferase (AST and ALT) ≤2.5 x upper limit ofnormal (ULN); ≤5.0 x ULN if there is liver involvement by the tumor.

19. Alkaline phosphatase ≤2.5 x ULN (≤5 x ULN in case of bone metastasis).

20. Total bilirubin ≤2.0 mg/dL, except in patients with Gilbert Syndrome who musthave a total bilirubin less than 3.0 mg/dL.

21. Able to receive outpatient treatment of elranatamab by meeting the followingcriteria:

22. Lives within 30minutes from the site of medication administration

23. Reliable caregiver present, who is able to watch participant continuously forat least until 48 hours after administration of first full treatment dose

24. No history of grade 3-4 CRS or grade 3-4 ICANS from other immune effector cellor bispecific antibody therapies

25. Resolved acute effects of any prior therapy to baseline severity or CTCAE Grade ≤1

26. Serum pregnancy test (for females of childbearing potential) negative at screening. a. Female patients of non-childbearing potential must meet at least 1 of thefollowing criteria: i. Achieved postmenopausal status, defined as follows: cessationof regular menses for at least 12 consecutive months with no alternativepathological or physiological cause; status may be confirmed with a serum folliclestimulating hormone (FSH) level confirming the postmenopausal state. ii. Have undergone a documented hysterectomy and/or bilateral oophorectomy. iii.Have medically confirmed ovarian failure. b. All other female patients (includingfemale patients with tubal ligations) are considered to be of childbearingpotential.

27. Agreement to adhere to Lifestyle Considerations (see section 5.3 and Appendix 2)throughout study duration

Exclusion Criteria:

1. Subjects with smoldering multiple myeloma, IgM multiple myeloma, Waldenstrom'smacroglobulinemia, amyloidosis, POEMS syndrome, and primary and secondary plasmacell leukemia, defined as circulating plasma cells ≥ 5%

2. Extramedullary relapse who does not meet criteria for measurable disease as above

3. Active malignancy other than Multiple Myeloma requiring treatment in the past 3years, with the exception of successfully treated non-metastatic squamous or basalskin carcinoma

4. Known CNS involvement by multiple myeloma

5. Active, uncontrolled autoimmune disorders

6. Active uncontrolled infection. Active infections must be resolved and/or controlledat least 14 days prior to enrollment.

7. Radiation therapy within 2 weeks prior to study entry (bone lesions requiringradiation may be treated with limited [ie, ≤25% of bone marrow in field] radiationtherapy during this period).

8. Last systemic treatment within 2 weeks or 5 half lives, whichever is shorter.Subjects can receive a maximum of 160mg of dexamethasone or equivalent duringscreening, but at least 7 days prior to start of therapy.

9. Last radiation treatment to multiple sites within 2 weeks and single site within 1week

10. History of autologous stem cell transplant within 100 days prior to studyenrollment.

11. History of allogeneic transplant within 1 year prior to study enrollment or activegraft versus host disease.

12. On immunosuppressive therapy for concurrent comorbid conditions

13. Other major uncontrolled medical comorbidities that may put patients at risk ofserious adverse event with treatment with study medication.

14. Clinically significant, uncontrolled cardiac disease

15. Grade ≥2 peripheral sensory or motor neuropathy

16. History of Guillan-Barre syndrome

17. Other surgical (including major surgery within 14 days prior to enrollment) orpsychiatric conditions including recent (within the past year) or active suicidalideation/behavior or laboratory abnormality that may increase the risk of studyparticipation or, in the investigator's judgment, make the participant inappropriatefor the study.

18. Previous administration with an investigational drug within 30 days (or asdetermined by the local requirement) or 5 half-lives preceding the first dose ofstudy intervention used in this study (whichever is longer).

19. Pregnancy or lactation

20. Known or suspected hypersensitivity to the study intervention or any of itsexcipients.