Survival after post-blinatumomab mAb1 relapse. (A) EFS as stratified according to the CD19 expression post-blinatumomab relapse. (B) OS as stratified according to the status of CD19 expression post-blinatumomab relapse. (C) OS as stratified according to receipt of interim salvage therapy between mAb1 and mAb2.