Treatment of relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma with everolimus (RAD001) and alemtuzumab: a Phase I/II study

Patients with relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL), and especially those with purine analogue refractory disease or TP53 deletion/mutation, had a poor prognosis prior to the introduction of therapy targeting B cell receptor signaling. The mammalian target of rapamycin (mTOR) inhibitor everolimus has biological activity in CLL and can mobilize CLL cells from the lymphoid tissues into the circulation. In this clinical trial we determined the maximum tolerated dose (MTD) of everolimus together with eight weeks of standard dose subcutaneous alemtuzumab (Phase I) and then evaluated the tolerability and efficacy of therapy of relapsed/refractory CLL with the combination of everolimus and alemtuzumab (Phase II). The maximum tolerated dose of oral everolimus was 2.5 mg three times/week. Therapy with everolimus and alemtuzumab was tolerable, but not sufficiently efficacious (33% partial responses, no complete responses) to recommend further development of the regimen.