Patients received cladribine at 5 mg/m2 intravenously each day on days 1–5. Those treated with vorinostat were given 400 mg orally each day on days 1–5 as well. Patients received alemtuzumab 30 mg intravenously once a day on days 1, 3, 5, 8, 12, 15, 17, 19, 22, 24 and 26. One treatment cycle was 28 days. All patients were treated with alemtuzumab and cladribine. Those whose white blood cell counts did not respond well after relapse were also treated with vorinostat. Status of clinical and molecular remissions was evaluated after 2–3 cycles.