Nivolumab in Multiple Myeloma Patients After Idecabtagene Vicleucel

Inclusion Criteria:

1. Written informed consent and HIPAA authorization for release of personal healthinformation signed by the participant or his/her legally authorized representative

2. Age ≥ 18 years at the time of consent

3. ECOG Performance Status (PS) of ≤ 1 at the time of enrollment. PS must be evaluatedwithin 14 days prior to enrollment.

4. Measurable disease according to IMWG 2016 criteria present within 28 days prior toide-cel infusion. Note that patients will NOT be required to have measurable diseaseat time of enrollment. Measurable disease is defined as:

5. Serum M-protein ≥1 g/dL (> 0.5 g/dL for IgA or IgM) OR

6. Urine M-protein ≥200 mg/24 h OR

7. Involved free light chain (FLC) level ≥10 mg/dL provided serum FLC ratio isabnormal

8. Previous treatment with idecabtagene vicleucel according to the FDA approved USprescribing information with a response of CR/sCR, VGPR or PR by IMWG 2016 criteriaevaluated no sooner than 3 weeks after idecabtagene vicleucel infusion when comparedto baseline disease evaluations collected no earlier than 28 days prior to ide-celinfusion. Note: The 28-day window applies to all assessments, even if assessmentswere performed on different days. Note: Participants who received non-conforming idecabtagene vicleucel who wereoriginally prescribed idecabtagene vicleucel according to the FDA approved label maybe considered for inclusion per the investigator's discretion.

9. Participants must be enrolled no sooner than 3 weeks and no later than 6 weeks fromthe date of the idecabtagene vicleucel infusion.

10. Recovered from all non-hematologic reversible acute toxic effects of prior therapy (other than alopecia) to ≤ grade 1 or baseline. Participants with grade ≤ 2treatment induced peripheral neuropathy are eligible. Participants with hematologicreversible acute toxic effects are allowed to participate if laboratory values meeteligibility parameters.

11. Demonstrate adequate organ function as defined in the table below; all screeninglabs to be obtained within 28 days prior to enrollment. The most recent labs priorto enrollment will be used to evaluate for eligibility if labs drawn more than onceduring screening.

12. Females of childbearing potential (FCBP) must have a negative serum pregnancy testwithin 72 hours prior to enrollment. NOTE: Females are considered of childbearingpotential unless they are surgically sterile (have undergone a hysterectomy,bilateral tubal ligation, or bilateral oophorectomy) or are postmenopausal (at least 12 consecutive months with no menses without an alternative medical cause). FCBP must be willing to use a highly effective contraceptive method (i.e., achievesa failure rate of <1% per year when used consistently and correctly) from the timeof informed consent until 5 months after last dose of nivolumab. Contraceptivemethods with low user dependency are preferable but not required (see table, adaptedfrom: 2020_09_HMA_CTFG_Contraception_guidance_Version_1.1_updated.pdf)

13. Ability of the participant to understand and comply with study procedures for theentire length of the study, as determined by the enrolling investigator

Exclusion Criteria:

1. Diagnosis of Waldenstrom macroglobulinemia, POEMS syndrome, or amyloidosis

2. History of/or active infection listed below:

3. Active infection requiring systemic therapy (NOTE: at discretion ofinvestigator, participants receiving treatment for an uncomplicated urinarytract infection or localized cellulitis may be eligible.)

4. Uncontrolled Human Immunodeficiency Virus (HIV) or hepatitis B infection. Wellcontrolled HIV infection (as defined by an undetectable viral load) and chronichepatitis B infection on appropriate prophylaxis can be considered perenrolling investigator discretion

5. Active hepatitis C infection. Participants with previously treated hepatitis Cinfection with documented eradication of their infection will be allowed toenroll.

6. Known history of active TB (Bacillus Tuberculosis)

7. Pregnant or breastfeeding (Note: breast milk cannot be stored for future use whilethe mother is being treated on study.)

8. Current evidence of active cytokine release syndrome or neurotoxicity (any grade)

9. Participants previously diagnosed with an additional malignancy must be disease-freefor at least 2 years prior to enrollment. Exceptions include basal cell or squamouscell skin cancer and in situ cervical or bladder cancer.

10. Treatment with any anti-myeloma therapy or investigational drug within 30 days priorto cycle 1 day 1 of nivolumab other than ide-cel with the exception oflymphodepleting chemotherapy or steroids for ide-cel therapy. Investigationalincludes drugs approved for human use but not approved for the indication.

11. Uncontrolled intercurrent illness including, but not limited to, ongoing or activeinfection, symptomatic congestive heart failure, unstable angina pectoris, cardiacarrhythmia, or psychiatric illness/social situations that would limit compliancewith study requirements as determined by the investigator

12. History of transplant:

13. Autologous stem cell transplant within 12 weeks of C1D1

14. Allogeneic stem cell transplant

15. Solid organ transplant

16. Active known or suspected autoimmune disease. Participants with Type 1 diabetesmellitus, hypothyroidism only requiring hormone replacement, skin disorders (such asvitiligo, psoriasis or alopecia) not requiring systemic treatment, or conditions notexpected to recur in the absence of an external trigger are permitted to enroll.

17. Known history of interstitial lung disease or known history of non-infectiouspneumonitis

18. Inability to take Pneumocystis jirovecii (PJP) prophylaxis (eithertrimethoprim-sulfamethoxazole, dapsone, or pentamidine)

19. A condition requiring systemic treatment with either corticosteroids (>10 mg dailyprednisone equivalent) or other immunosuppressive medications within 14 days of C1D1 (Note: Inhaled or topical steroids, and adrenal replacement steroid doses > 10 mgdaily prednisone equivalent, are permitted in the absence of active autoimmunedisease)

20. Prisoners or participants who are involuntarily incarcerated

21. Known history of myocarditis, regardless of etiology

22. Known history of allergy or hypersensitivity to study drug components

23. History of serious side effects to nivolumab or ipilimumab, as defined by theenrolling investigator