- 1) Failed to meet National Cancer Institute (NCI) Working Group criteria for complete or partial response after therapy with a regimen containing FLU (fludarabine phosphate) (or another nucleoside analog, e.g. 2-chlorodeoxyadenosine [2-CDA], pentostatin) or experience disease relapse within 12 months after completing therapy with a regimen containing FLU (or another nucleoside analog)