Selinexor (KPT-330) in Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma (DLBCL)

This is a multicenter, open label, Phase 2b study of the selective inhibitor of nuclear export (SINE) selinexor (40 or 60 milligrams \[mg\]) given orally (PO) to participants with R/R DLBCL). The study is being conducted in 2 parts (Part 1 and Part 2). For Part 1, a fixed 60 mg dose of selinexor is given orally to 130 participants with R/R DLBCL who have no therapeutic options of demonstrated clinical benefit and who meet eligibility criteria and have none of the exclusion criteria will be enrolled to receive selinexor until either disease progression or intolerance has occurred. For Part 2, approximately 110 participants (55 in each arm) are planned to be enrolled. Participants will be randomized (open label) in a 1:1 ratio to either Arm A (40 mg) or Arm B (60 mg) and will be stratified based on history of prior autologous stem cell transplantation (ASCT) versus no prior ASCT. All the participants will be followed until disease progression and/or death.