Cyclophosphamide With Biochemical Progression During Lenalidomide-Dexamethasone Treatment for Relapsed/Refractory Multiple Myeloma (MM)

This protocol is a phase II multicenter, open label study designed to determine whether the addition of Cyclophosphamide to Rd (CRd) treatment significantly increases response rates and prolonged the outcome (PFS, OS) in patients who experienced a biochemical relapse, without CRAB under Rd treatment. The treatment period includes: administration of the combination CRd for 9 cycles. In order to assess the efficacy and safety of treatment, patients will attend the study center visits at least every 2 weeks. The response will be assessed after each cycle. During the LTFU period, after development of confirmed PD, all patients are to be followed for survival every 1-3 months via telephone or office visit.