The Latin American experience of allografting patients with severe aplastic anaemia: real-world data on the impact of stem cell source and ATG administration in HLA-identical sibling transplants.

We studied 298 patients with severe aplastic anaemia (SAA) allografted in four Latin American countries. The source of cells was bone marrow (BM) in 94 patients and PBSCs in 204 patients. Engraftment failed in 8.1% of recipients with no difference between BM and PBSCs (P=0.08). Incidence of acute GvHD (aGvHD) for BM and PBSCs was 30% vs 32% (P=0.18), and for grades III-IV was 2.6% vs 11.6% (P=0.01). Chronic GvHD (cGvHD) between BM and PBSCs was 37% vs 59% (P=0.002) and extensive 5% vs 23.6% (P=0.01). OS was 74% vs 76% for BM vs PBSCs (P=0.95). Event-free survival was superior in patients conditioned with anti-thymocyte globulin (ATG)-based regimens compared with other regimens (79% vs 61%, P=0.001) as excessive secondary graft failure was seen with other regimens (10% vs 26%, P=0.005) respectively. In multivariate analysis, aGvHD II-IV (hazard ratio (HR) 2.50, confidence interval (CI) 1.1-5.6, P=0.02) and aGvHD III-IV (HR 8.3 CI 3.4-20.2, P<0.001) proved to be independent negative predictors of survival. In conclusion, BM as a source of cells and ATG-based regimens should be standard because of higher GvHD incidence with PBSCs, although the latter combining with ATG in the conditioning regimen could be an option in selected high-risk patients.

Therapeutic choices in patients with Ph-positive CML living in Mexico in the tyrosine kinase inhibitor era: SCT or TKIs?

A total of 72 patients with Ph-positive CML in first chronic phase were followed during a 6-year period in two different institutions in México. Among them, 22 were given a reduced-intensity allogeneic SCT, whereas 50 were given a tyrosine kinase inhibitor (TKI), mainly imatinib mesylate. The 6-year overall survival (OS) after the therapeutic intervention for patients allografted or given a TKI was 77 and 84%, respectively (P, NS); the median OS for both groups has not been reached, being above 90 and 71 months, respectively (P, NS). The freedom from progression to blast or accelerated phases was also similar for both groups, as well as the overall OS after diagnosis. Most patients allografted (91%) chose this treatment because they were unable to afford continuing treatment with the TKI, whereas most treated with the TKI (84%) were given the treatment without charge, through institutions able to pay for their treatment. The median cost of each nonmyeloablative allograft was US$18,000, an amount that is enough to cover 180 days of treatment with imatinib (400 mg per day) in México. Cost considerations favor allogeneic SCT as a 'once only' procedure whereas lifelong treatment with an expensive drug represents an excessive burden on resources.

Non-myeloablative stem cell transplantation in patients with relapsed acute lymphoblastic leukemia: results of a multicenter study.

Using non-myeloablative conditioning, allogeneic hematopoietic stem cell transplantation (HSCT) was conducted in 43 ALL patients in a CR2. The median age of the patients was 19 years. Patients received oral busulfan 4 mg/kg/day for 2 days; i.v. cyclophosphamide 350 mg/m(2)/day for 3 days; and i.v. fludarabine 30 mg/m(2)/day for 3 days. Oral cyclosporin A 4 mg/kg was started and methotrexate 5 mg/m(2) was delivered on days 1, 3, 5 and 11. The median CD34+ cell dose received was 5.0 x 10(6)/kg. The medium time to achieve a granulocyte count above 0.5 x 10(9)/l was 14 days. Thirteen patients were alive 30-1050 days after the HSCT. The 3-year overall survival rate was 30%. Ten patients (23%) developed acute GVHD, whereas eight patients (18.6%) developed chronic GVHD. Thirty patients died between days 47 and 1050 after the HSCT, most of them (70%) because of an ALL relapse. One hundred-day mortality was 15%, whereas transplant-related mortality was 21%. These results are inferior to those obtained using the same allografting method in other leukemias, probably as a consequence of poor susceptibility to the graft-versus-leukemia effect of the ALL cells beyond first remission as compared with other hematological malignancies.

Non-myeloablative hematopoietic stem cell transplantation is of limited value in advanced or refractory acute myeloblastic leukemia. The Mexican experience.

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective strategy for preventing relapse of acute myelogenous leukemia (AML). We analyzed the outcome of 31 primary AML patients who received a reduced-intensity conditioning regimen for allogeneic HSCT in first or second remission. Thirty-one AML patients, 20 in first complete remission (FCR), 8 in second complete remission (SCR) and 3 in a partial remission (SPR) were included. All received busulfan 4 mg/kg/d/2 days, fludarabine 30 mg/m(2)/d/3 days and cyclophosphamide 350 mg/m(2)/d/3 days as conditioning regimen. The median number of CD34+ cells infused was 5.6 x 10(6)/kg and 5.2 x 10(6) in FCR and SCR group, respectively. All patients received cyclosporine-A (CsA) and methotrexate as graft vs. host disease (GvHD) prophylaxis. All patients showed myeloid engraftment (neutrophils >0.5 x 10(9)/l) after a median of 13 days in FCR group and 15 days in SCR group. Platelet recovery >20 x 10(9)/l was achieved after a median of 13 days in both groups. Relapse for 20 patients in FCR was 35% compared to 91% for 11 in SCR/SPR (p < 0.05). Conclusions. Reduced-intensity conditioning followed by allogeneic HSCT can induce stable remission in primary AML patients transplanted in FCR. A high relapse rate was documented in patients with refractory or relapsed AML.

Outpatient allografting using non-myeloablative conditioning: the Mexican experience.

A group of 132 patients with both malignant and nonmalignant conditions was allografted using the 'Mexican' method of non-ablative conditioning. The conditioning was delivered on an outpatient basis and the procedure was planned to be conducted on outpatients in all cases. While 103 patients (78%) were able to complete the procedure totally as outpatients, 29 (22%) were hospitalized because of fever, mucositis or acute graft-versus-host disease. In a multivariate analysis, although differences were not statistically significant, it was found that the patients who were allografted as outpatients had higher levels of hemoglobin (12 versus 11.8 g/dl), higher platelet counts (248 versus 191 x 10(9)/l), lower white blood cell counts (11.7 versus 12.4 x 10(9)/l), higher Karnofsky scale scores (100 versus 90%) and lower creatinine levels (0.9 versus 0.93 mg/dl). A total of 86% of the patients with normal values for these variables could be allografted as outpatients, whereas only 67% of those with abnormal values completed the entire procedure as outpatients. It is concluded that allografting can be accomplished totally on an outpatient basis using the 'Mexican' reduced intensity-conditioning regimen.

Autologous peripheral blood stem cell transplantation in multiple myeloma using oral versus I.V. melphalan.

Autologous peripheral blood stem cell transplantation is the therapy of choice for the treatment of multiple myeloma (MM) patients younger than 70 years old. Between August 1993 and November 2004, 54 patients with MM were autografted after conditioning with high-dose oral melphalan 140 mg/m(2) in combination with etoposide and carmustine (28 patients) or with high-dose melphalan 200 mg/m(2) I.V. (26 patients). The oral and IV melphalan groups were comparable. There were no significant differences in disease-free survival (DFS) and overall survival (OS) between the groups; however, in patients transplanted in remission, OS and DFS were better in the I.V. melphalan group. Four good-prognostic factors were identified: interval between diagnosis and transplant <18 months, number of prior chemotherapy lines < or =2, remission status (complete or partial), and the use of I.V. melphalan. In conclusion, I.V. melphalan is the therapy of choice for conditioning patients with MM who are in remission.

The early referral for reduced-intensity stem cell transplantation in patients with Ph1 (+) chronic myelogenous leukemia in chronic phase in the imatinib era: results of the Latin American Cooperative Oncohematology Group (LACOHG) prospective, multicenter study.

Using a reduced-intensity stem cell transplantation (RIST) schedule, 24 patients with Philadelphia (Ph1) (+) chronic myelogenous leukemia (CML) in first chronic phase (CP) were prospectively allografted in four Latin American countries: México, Brazil, Colombia and Venezuela, using HLA-identical siblings as donors. The median age of the patients was 41 years (range 10-71 years); there were eight females. Patients received a median of 4.4 x 10(6)/kg CD34 cells. The median time to achieve above 0.5 x 10(9)/l granulocytes was 12 days, range 0-41 days, and the median time to achieve above 20 x 10(9)/l platelets was also 12 days, range 0-45 days. In all, 22 patients are alive 81-830 (median 497) days after RIST. The 830-day probability of survival is 92%, and the median survival has not been reached, being beyond 830 days. A total of 11 patients (46%) developed acute graft-versus-host disease (GVHD), and seven of 23 (30%) developed chronic GVHD. Two patients died 43 and 210 days after RIST, one as a result of sepsis and the other of chronic GVHD. The 100-day mortality was 4.4%, and transplant-related mortality was 8%. RIST for patients with CML in CP appears to be an adequate therapeutic option.