Terminated this trial and added a Lenalidomide arm to KCP-330-017

This is an open-label, randomized clinical study with two stages to assess the maximum tolerated dose (MTD), efficacy, and safety of selinexor, lenalidomide, and dexamethasone (SLd) in patients with relapsed/refractory (RR) multiple myeloma (MM). The stages are dose escalation (Phase 1) and expansion (Phase 2).

In Phase 1 (Dose Escalation), patients will be randomized to either once-weekly (Arm A) or twice- weekly (Arm B) dosing with selinexor. Dose escalation will be performed within each arm for both lenalidomide and selinexor to determine the selinexor MTD for that arm. Each arm will be expanded until approximately 17 patients have been treated at the MTD in each arm. The Sponsor and Investigator will review the MTD, efficacy, and safety data from Phase 1 to determine which dose schedule (Arm A or B) to be used as the RP2D dose in the Expansion Phase.

In Phase 2 (Expansion), patients who had received the MTD dose that was nominated for RP2D will continue at the same dose. Patients who did not receive the RP2D for that arm will stay on their Phase 1 dose. Additional patients will be accrued, as needed, to achieve the target population size of approximately 34 patients at the RP2D.

Inclusion Criteria:

• Histologically confirmed diagnosis, measurable disease and evidence of disease progression of MM.
• Relapsed or refractory to the most recently received therapy. Relapsed is defined as documented evidence of PD after achieving at least SD for ≥ 1 cycle. Refractory disease is defined as ≤ 25% response (i.e., patients never achieved minimal response or better) or progression during therapy or within 60 days after completion of therapy.
• Symptomatic MM, based on IMWG guidelines. Patients must have measurable disease.

Exclusion Criteria:

• Smoldering MM.
• Multiple myeloma that does not express M-protein or FLC (i.e., non-secretory MM is excluded), and quantitative immunoglobulin levels cannot be used instead.
• Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome
• Active MM involving the central nervous system (CNS).