Haploidentical Stem Cell Transplantation (SCT) Using Flamsa Regimen As Salvage Chemotherapy

Abstract

Haploidentical donors are alternative stem cell sources for the patients without matched related and unrelated donors. Finding a full match unrelated donor takes at least 6 months. Most of the patients who have advanced acute leukemia die during this period. Unfortunately, they also loose the chance of haploidentical stem cell transplantation (SCT).Aim: To report the outcome of six patients whom underwent haploidentical stem cell transplantation using FLAMSA regimen as initial reduction of leukemic burden.Patients and Treatment: There were six patients (F/M: 3/3) who admitted to transplantation unit between November 2012 and December 2013. Table 1 shows the characteristics of patients. Patients received fludarabine 30mg/m2, ARA-C 2gm/m2, Amsacrine 100 mg/m2 (FLAMSA) consequently 4 days before the intiation of conditioning protocol. According to the conditioning protocol number of the rest days changed (Table 2). For transplantation G-CSF mobilized peripheral blood stem cells were used. No graft manipulation was performed, 5x10e6 CD34+ cells/kg were requested. Graft versus host disease (GVHD) prophylaxis: Cyclophosphamide 50mg/kg/day (+3,+4), Tacrolimus 0.03 mg/kg/day +5 and MMF 3x15mg/kg +6 was started. In the absence of GVHD, MMF was discontinued by day +30, tacrolimus was tapered from day +60 to +100.Results: All of the patients had active diseases. Three of the six patients died during conditioning. Transplantation related mortality (TRM) was 50%. The other three patients were alive on the day 100. Overall survive (OS) on day 100 was %50. Two patients (22%) lived beyond 6 months. Of these two, one of them has completed the first year (16%) and is still alive without GVHD or disease relaps. Outcome of the patients are shown in Table 2.Discussion: The patient number is so restricted to draw any conclusions from this report but we know that Allogeneic SCT is the most effective treatment for a variety of hematologic malignancies. The current data suggest that the chosen sequential strategy of intensive chemotherapy followed after a few days of rest by allogeneic SCT has encourging results. Combining this modality with haploidentical transplantation may represent a step forward in the treatment of refractory hematologic malignancies.Table1:Patients’ and donors’ characteristicsPatient noGenderPatient AgeDiagnosisTx noPRADonorDonor age1M37ALL1stNegBrother442F47ALL1stNegSon233F44AML1stNegSon224M41AML3rd(2MSD)NegMother655F26AML2nd(1MUD)NegMother546F46ALL2nd(1MSD)NegSister53 MMale F: Female ALL: Acute lymphoblastic leukemia, AML: Acute myeloblastic leukemia, Tx no: Number of transplantation, PRA: Panel Reactive Antibody, Neg: Negative MSMatch Sibling Donor, MUD Match Unrelated Donor)Abstract 5925 Table 2:Patients’ outcomePatient noConditioning regimenRest day (s) after FLAMSAEngraftment PLT 20/ NEU0.5Chimerism on day 30Engraftment failureReinfusion of peripheral blood CD34+GVHD Grade 3-4Comorbid conditionStatus after SCT1MEL50mg/m2/day (-5,-4) TBI Gy (-3,-2,-1)-6YesFullYes+105.dayYesNoExitus +210 day GVHD2MEL50mg/m2/day (-5,-4) TBI 4Gy(-3,-2,-1)-6YesFullNoNoNoNoAlive +390day3MEL 200mg/m2 (-1)-3,-2No----IPAExitus+14day Gram negative septicemia4BU 3.2mg/kg/day (-5,-4,-3,-2) MEL 140mg/m2/day (-1)-9,-8,-7,-6No----IPAExitus+12day Candidemi 5MEL 200mg/m2 (-1)-3,-2YesFullYes+125dayNoIPAAlive +240 day6BU 3.2mg/kg/day (-5,-4,-3,-2) MEL 140mg/m2/day (-1)-9,-8,-7,-6No--NAPanniculitis IPAExitus day 0 BUBusulfan, Mel: Melfelan, TBI: Total Body Irradiation, PLT 20: Platelet > 20.000 NEU 0.5: Neutrophil>500, GVHD: Graft versus Host Disease, IPA: Invasive Pulmonary Aspergillozis, DisclosuresNo relevant conflicts of interest to declare.