Study of Carfilzomib, Lenalidomide, Dexamethasone and Belantamab Mafodotin in Multiple Myeloma

INCLUSION CRITERIA for all subjects: 1. Written informed consent and HIPAA authorization for release of personal health information signed by the subject or his/her legally authorized representative. NOTE: HIPAA authorization may be included in the informed consent or obtained separately. 2. Age greater than or equal to 18 years at the time of consent. Because no dosing or adverse event data are currently available on the use of belantamab mafodotin as a single agent or in combination with KRd in subjects less than 18 years of age, children are excluded from this study. 3. ECOG Performance Status of less than or equal to 2 4. Demonstrate adequate organ function 5. Adequate cardiac function as defined by a greater than 40% left ventricular ejection fraction (LVEF) by ECHO, cardiac MRI or MUGA a. Note for subjects in phase II: if a cycle of pre-study induction therapy containing a PI or anthracycline was administered, assessment of the LVEF must be repeated. 6. For those with symptomatic pulmonary disease with Grade 2 or higher symptoms (e.g. COPD, asthma) or other signs / symptoms of pulmonary disease, adequate pulmonary function as defined by a FEV1 greater than or equal to 50% of predicted and DLCO/VA greater than or equal to 50% of predicted 7. Females of childbearing potential (FCBP) must have two negative serum pregnancy tests during screening: the first within 10-14 days prior to first dose of study treatment and the second within 24 hours prior to first dose of study treatment. NOTE: Females are considered of childbearing potential unless they are surgically sterile (have undergone a hysterectomy, bilateral tubal ligation, or bilateral oophorectomy), are amenorrhoeic for less than 2 years without history of a hysterectomy and oophorectomy must have a follicle stimulating hormone value in the postmenopausal range upon screening evaluation; or are postmenopausal (at least 12 consecutive months with no menses without an alternative medical cause). 8. FCBP must be willing to use 2 effective contraceptive methods (at least one that is highly effective) or abstinence starting from the time of informed consent, while on belantamab mafodotin and lenalidomide. If either drug is discontinued, 2 effective forms of contraception should be continued until at least 4 weeks after the last dose of lenalidomide, and 1 form of effective contraception should be continued until 4 months post last dose of belantamab mafodotin. FCBP should use effective contraception or abstinence from consent until 30 days after last treatment with carfilzomib, and males with a partner of childbearing potential must use effective contraception or abstinence for at least 90 days post last dose of carfilzomib. 9. Male subjects must agree to the following from the first dose of study treatment until 6 months after the last dose of belantamab mafodotin, to allow for clearance of altered sperm: 1. Refrain from donating sperm PLUS either: b. Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent. OR c. Must agree to use effective contraception/barrier as detailed below: Agree to use a male condom, even if they have undergone a successful vasectomy, and female partner of reproductive potential to use an additional highly effective contraceptive method with a failure rate of less than 1% per year 10. FCBP must agree not to donate eggs (ova, oocytes) for the purpose of reproduction during the intervention period and for at least 4 months after the last dose of study intervention belantamab mafodotin, at least 30 days after the last dose of carfilzomib, and at least 4 weeks after the last dose of lenalidomide. 11. As determined by the enrolling physician, ability of the subject to understand and adhere with study procedures for the entire length of the study 12. Ability to swallow oral medications 13. Willing to refrain from using contact lenses while participating in this study INCLUSION CRITERIA - Phase I treatment for Relapsed or Relapsed/Refractory MM: 1. Subjects with Relapsed or Relapsed/Refractory MM who have had at least 1 line of prior therapy. a. Refractory is defined as less than 25% reduction in M-protein or progression of disease during treatment or within 60 days after cessation of treatment b. A line of therapy is defined as one or more cycles of a planned treatment program. This may consist of one or more planned cycles of single-agent therapy or combination therapy, as well as a sequence of treatments administered in a planned manner. A new line of therapy starts when a planned course of therapy is modified to include other treatment agents (alone or in combination) as a result of disease progression, relapse, or toxicity. A new line of therapy also starts when a planned period of observation off therapy is interrupted by a need for additional treatment for the disease. 2. Subjects must have measurable disease, as defined by at least one of the following: a. Serum monoclonal protein level greater than or equal to 0.5 g/dL b. 24-hour urinary M-protein greater than or equal to 200 mg c. Involved free light chain level greater than or equal to 10 mg/dL, along with an abnormal free light chain ratio (defined as less than 0.26 or greater than 1.65). 3. Subject must have not progressed on full dose lenalidomide previously (25 mg on days 1-21 of a 28-day cycle or its dosing equivalent based on renal function at the time of progression) 4. Prior to enrollment: 1. There should be a washout period of ≥14 days from any prior chemotherapy AND 2. The subject must have adequate recovery from toxicity of prior chemotherapy as defined by the following: i. Hematologic lab results within parameters noted in Table 3.2.1 ii. Non-hematologic toxicity resolved to grade 1 or baseline with the following exceptions: <!-- --> 1. Subjects who have started a course of antibiotic therapy for infect