Response rate based on prior treatment. Response rate as demonstrated by ORR and nCR/CR is shown for each treatment arm, PAN-BTZ-Dex and Pbo-BTZ-Dex, and for each prior treatment subgroup analyzed: prior treatment with an IMiD, prior treatment with bortezomib and an IMiD, and patients who received ≥2 prior regimens including bortezomib and an IMiD. Statistical analyses were conducted for comparison of ORR between treatment arms.