• Voluntary consent must be given before performance of any study related procedure.

• Male or female subjects ≥18 years.

• Multiple myeloma subjects with at least 2 prior therapies that included lenalidomide and proteasome inhibitor combined or in different regimens, and refractory to most recent line of therapy.

• Measurable disease as defined by any of the following:

‣ Serum M-protein level ≥0.5 g/dL OR

⁃ Urine M-protein level ≥200 mg/24 hours; OR

⁃ Light chain multiple myeloma without measurable disease in the urine: serum Ig free light chains (FLC) ≥10 mg/dL and abnormal serum Ig kappa/lambda FLC ratio.

• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.

• Female subjects who:

∙ Are postmenopausal (see Appendix 4 for definition) for at least one year before the screening visit, OR

‣ Are surgically sterile, OR

‣ Females of childbearing potential or male subjects with female partners of childbearing potential shall be required to use effective contraceptive methods (double barrier method, intrauterine device, oral contraception or abstinence) starting two weeks before first study drug(s) administration, while on therapy and for 16 weeks following the last dose of study drug(s). A woman is considered of childbearing potential, i.e., fertile, following menarche and until becoming postmenopausal unless permanently sterile. Any of the following highly effective methods of contraception are accepted:

⁃ Established use of oral, intravaginal, or transdermal combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation.

• Established use of oral, injectable, or implantable progestogen-only hormonal contraception associated with inhibition of ovulation.

• Placement of an intrauterine device or intrauterine hormone-releasing system.

• Barrier methods of contraception: male condom with either cap, diaphragm or sponge with spermicide (double-barrier methods). The use of double-barrier methods should always be supplemented with the use of a spermicide. Female condom and male condom should not be used together.

• Male sterilization (provided that the partner is the sole sexual partner of the subject and that the sterilized partner has received medical assessment of the surgical success).

• Sexual abstinence.

• Female subjects must agree not to donate eggs (ova, oocytes) for the purposes of assisted reproduction starting two weeks before first study drug(s) administration, while on therapy and for 16 weeks following the last dose of study drug(s).

‣ Females of childbearing potential must have a negative serum or urine pregnancy test prior to enrollment.

• Male subjects, even if surgically sterilized (i.e., status post vasectomy), who:

∙ Agree to practice effective barrier contraception during the entire study treatment period from the time of signing the informed consent through and through four months after the last dose of study drug(s) (female and male condoms should not be used together), or

‣ Agree to practice true abstinence during the entire study treatment period from the time of signing the informed consent through four months after the last dose of study drug(s), when this is in line with the preferred and usual lifestyle of the subject. (Periodic abstinence \[e.g., calendar, ovulation, symptothermal, post ovulation methods for the female partner\] withdrawal, spermicides only, and lactational amenorrhea are not acceptable methods of contraception.)

• Due to the teratogenicity of pomalidomide and the lack of adequate reproductive toxicity data for isatuximab and/or elotuzumab, in addition to the user independent highly effective method of contraception, a male or female condom with or without spermicide, diaphragm, or cervical cap is required. Male condom and female condom should not be used together (due to risk of failure with friction).