KappaMab: This phase II trial is evaluating an investigational antibody therapy (KappaMab) in combination with lenalidomide (a chemotherapy drug) and dexamethasone (a steroid) for the treatment of relapsed Multiple MyelomaA Phase IIb, open label, sequential cohort study comparing KappaMab alone to KappaMab in combination with lenalidomide and low dose dexamethasone (MRd) in Relapsed Refractory Multiple Myeloma

Inclusion

Age 18 years and above.

2. Confirmed diagnosis of MM as per IMWG criteria,

3. ECOG performance status 0-2

4. Relapsed and/or refractory kappa restricted MM

5. Received 1-3 prior lines of therapy
a. Induction + ASCT + maintenance = 1 line of therapy
b. (No prior lenalidomide therapy)

6. Adequate liver and kidney function (<2 x institutional upper limit of normal)

7. Platelet count > 75 x 10^9/L, absolute neutrophil count > 1.0 x 109/L

8. No contraindication to the use of KappaMab, lenalidomide or dexamethasone

9. Patient has voluntarily agreed and has given written informed consent.

10. Life expectancy of > 8 weeks

11. Patient must be > 2 weeks from prior chemotherapy, radiotherapy, biological therapy, immunotherapy, major surgery or any other investigational anti-cancer therapy prior to the first dose of study drug

12. All females of childbearing potential (FOCBP)** must agree to have two medically supervised negative pregnancy tests : one at screening, patient undertaking contraceptive controls and one 24 hours prior to dosing of study drug. Patient must use two reliable methods of contraception simultaneously or to practice complete abstinence from any sexual contact during the following time periods related to this study: 1) for at least 28 days before starting study; 2) while participating in the study; 3) dose interruptions; and 4) for at least 28 days after study treatment discontinuation. The two methods of reliable contraception must include one highly effective method and one additional effective method to prevent pregnancy, not plan on conceiving children during or within 6 months following lenalidomide

13. All male participants must practice complete abstinence or agree to use a condom during sexual contact with a pregnant female or a female of childbearing potential while participating in the study, during dose interruptions and for at least 28 days following study drug discontinuation, even if he has undergone a successful vasectomy.