Fludarabine, Amsacrine, High-Dose Cytarabine and Total Body Irridation Followed by Allogeneic Stem Cell Transplantation for the Treatment of High Risk or Relapsed Acute Lymphoblastic Leukemia.

In this prospective study we examined the use of an intensified conditioning regimen followed by allogeneic blood-stem-cell transplantation (BSCT) for the treatment of young adults in physically good condition with relapsed or high risk acute lymphoblastic leukaemia (ALL). Eleven patients with ALL received FLAMSA chemotherapy (fludarabine 30mg/m² - cytarabine 2000mg/m² -amsacrine 100 mg/m² on day −10, − 9, − 8and −7), Anti-Thymocyte-Globulin (ATG 20 mg/kg BW on day −6, −5 and −4) and fractionated TBI (2 x 2 Gy on day −3, − 2 and −1) followed by matched unrelated donor (n=10) or matched sibling donor (n=1) SCT. The principle reasons for high risk stratification were refractory disease during first-line induction therapy (6, 55%), relapse (2, 18%), extramedullary disease manifestation (1, 9%), ALL subtype (6, 55%), unfavorable cytogenetics (5, 45%) and white blood count >30000 μL at time of diagnosis (3, 27%). After a median follow-up time of 604 days (range 202 – 1042 days) 8 patients (73%) are alive and 3 patients (27%) died. The median overall survival was not reached. Two patients died after relapse on days +121 and +449, another patient died from treatment related complications (HUS-TTP) on day +87. One patient relapsed on day +200 and is currently alive, the remaining 7 patients are alive and free of desease. Treatment related toxicities were acceptable. With 6 out of 11 patients developing grade III/IV infections during neutropenia, infectious complications remained of major importance. Other non-haematological side effects seen within this group of patients were less frequent and almost exclusively limited to gastrointestinal toxicities. Five patients (45%) had grade III/IV mucositis and 5 patients (45%) had grade III/IV nausea, while 4 patients (36%) showed grade III/IV diarrhoea. There was no case of acute toxicity related to the cardiavascular or central nervous system. The incidence of acute GvHD (aGvHD) was 36% (n = 4) and limited to grades II-III. Eight patients were evaluable for chronic GvHD (cGvHD). Out of those 4 patients (36%) developed cGvHD (3 limited disease, 1 extensive disease). We conclude that allogeneic transplatation after the FLAMSA-ATG-TBI regimen is feasible and provides effective therapy for this group of high-risk patients.