Personalized Selinexor-based Therapy for Relapsed/Refractory Multiple Myeloma

This study is a single institution, open-label phase II study to evaluate the overall response rate achieved with selinexor and dexamethasone based three drug combination therapy, selected by physician's choice, in patients with relapsed/refractory multiple myeloma. Patients with RRMM will be eligible for enrollment. During screening, in addition to standard of care disease assessments, participant's bone marrow aspirate will be evaluated using a novel ex vivo Myeloma Drug Sensitivity Testing platform (My-DST). The following agents will be eligible for physician's choice, and in parallel evaluated for sample sensitivity in MyDST: pomalidomide, carfilzomib and daratumumab. Agents will be tested individually, in combination with selinexor and in combination with selinexor and dexamethasone. Results from MyDST will be not be available to investigators at time of treatment assignment, but will be evaluated to better characterize test performance and relationship with treatment outcomes. Investigators will assign patients to one of the following treatment combinations: Selinexor/Pomalidomide/Dexamethsone (SPd), Selinexor/Daratumumab/Dexamethasone (SDd) or Selinexor/Carfilzomib/Dexamethasone (SKd). Investigators will use patient specific considerations such as prior therapeutic exposures, response to / tolerance of prior therapies and comorbid conditions which may increase risk for toxicity with specific agents to guide expert judgement in selecting partner agent for selinexor and dexamethasone. Treatment will continue until progression of disease, unacceptable toxicity or death. This study will evaluate if physician's choice partner drug selection for selinexor based combination therapy in RRMM will lead to an overall response rate of 75% or higher.