The combination of purine analogs and alemtuzumab have been administered simultaneously safely with promising additive activity in other relapsed and refractory lymphocytic leukemias. A recent case series reported patients with relapsed and/or refractory ALL who failed several induction chemotherapies to achieve complete responses to fludarabine and alemtuzumab combination regimens. All patients were able to proceed to allogeneic SCT with refractory ALL patient relapsing at 8 months while relapsed patients remain in remission at 6 and 24 months.