Low incidence of transplantation-related acute complications in patients with chronic myeloid leukemia undergoing allogeneic stem cell transplantation with a low-dose (550 cGy) total body irradiation conditioning regimen

Management of advanced-phase chronic myeloid leukemia

The management of chronic myeloid leukemia (CML) in accelerated or blast phase (advanced phase) remains a significant challenge despite the introduction of very effective tyrosine kinase inhibitors (TKIs). The biology of advanced-phase CML is complex and engages several pathways that are not optimally targeted by TKIs. Allogeneic stem cell transplantation remains the only potentially curative therapy, but the effectiveness of this conventional approach is limited. New strategies are required to improve the outlook for these patients.

The Incidence and Severity of Oral Mucositis among Allogeneic Hematopoietic Stem Cell Transplantation Patients: A Systematic Review

Oral mucositis (OM) is a debilitating early adverse effect of allogeneic hematopoietic stem cell transplantation (HSCT). The intensity of the conditioning regimen correlates with the incidence and severity of OM, but no studies have analyzed this relationship among various conditioning regimens. We performed a systematic review on the incidence and outcomes of OM in allogeneic HSCT patients and analyzed this association. A comprehensive search of several databases (Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Cochrane CRCT, Cochrane DSR, Scopus) from 1990 to 2014 for studies of OM in allogeneic HSCT patients was conducted. Professional societies' meeting abstracts were also searched. Grade of OM was analyzed based on the World Health Organization (WHO) or National Cancer Institutes (NCI) Common Terminology Criteria for Adverse Events scales. Severe mucositis was defined as either grades 2 to 4 or grades 3 and 4, depending on the studies' definition of severity. Cohorts were analyzed based on regimen intensity; ie, reduced-intensity conditioning (RIC) (including nonmyeloablative) and myeloablative (MA). Random effect (RE) and standard logistic models weighted by the number of patients in each cohort were used for comparisons. A total of 624 studies were generated from the search. Of the 395 patients in 8 eligible MA regimen studies, 73.2% experienced any OM, whereas in 245 patients in the 6 eligible RIC regimen studies, 86.5% experienced any OM (chi-square P < .0001; RE, P = .05). Severe (grades 2 to 4) OM occurred among 79.7% of the WHO/NCI-graded MA patients and 71.5% of RIC patients (chi-square, P = .0421; RE, P < .01). In comparing graft-versus-host disease (GVHD) prophylaxis, only 55.4% of patients receiving nonmethotrexate regimens experienced OM; this was lower (chi-square, P < .0001; RE, P = .06) than that found among patients who received methotrexate (83.4%), either standard or reduced dose. Besides NCI and WHO grading scales, other scales included in the studies were Oral Mucositis Index, the Southwest Oncology Group Criteria, and Eastern Cooperative Oncology Group scale. To our knowledge, this is the first analysis on OM in allogeneic HSCT patients with respect to conditioning regimens, and we observed that RIC regimens led to a high incidence of OM similar to that of MA regimens. Clinical trials on treatment of OM are lacking, emphasizing the essential need for prospective studies in this arena. A significant variance in the criteria for grading OM underscores the importance of establishing a standard grading system for OM measurement in future allogeneic HSCT clinical trials.

Low incidence and severity of graft-versus-host disease after outpatient allogeneic peripheral blood stem cell transplantation employing a reduced-intensity conditioning

BACKGROUND

The prevalence and features of graft-versus-host disease (GVHD) in patients receiving allografts using peripheral blood stem cells (PBSCs) after a reduced-intensity conditioning (RIC) regimen are not well known. Several features of GVHD in patients at two institutions using RIC were assessed.

METHODS

We analysed the overall survival (OS) and prevalence of GVHD in patients who underwent outpatient allogeneic PBSC transplantation after RIC between October 1998 and July 2008.

RESULTS

We included 301 patients with a median age of 30 yrs (range, 1-71 yrs). In 37 cases, allogeneic peripheral blood stem cell transplantation was indicated for non-malignant disease, and in 264 for malignant disease. The median OS was 35 months. The estimated 3-yr OS was 48%. A total of 154 patients developed GVHD: there were 64 acute, 50 chronic and 40 cases that progressed from acute to chronic. Of the 104 patients with acute GVHD (aGVHD), 40% had grade I and 60% had grades II-IV. Of the 90 patients with chronic GVHD (cGVHD), 67% had limited and 33% had extensive forms. A total of 160 patients died, 40 as a result of GVHD (24 from aGVHD and 16 from cGVHD), 50 as a result of progressive disease and 70 from diverse causes.

CONCLUSIONS

The incidence of GVHD was lower than in other series using conventional myeloablative preparative regimens. Most importantly, the severity of GVHD did not significantly affect the long-term survival.

Total body irradiation before an allogeneic stem cell transplantation: is there a magic dose?

PURPOSE OF REVIEW

To review the outcomes of allogeneic transplantation with regimens of varying total body irradiation (TBI) doses (0-1575 cGy), with an emphasis on reduced-intensity conditioning (RIC) regimens.

RECENT FINDINGS

RIC regimens with a broad range of TBI doses (0, 200, 400, 550, and 800 cGy) have been studied. Durable donor stem cell engraftment occurred in most patients, with a low rate of toxicity and nonrelapse mortality. Patients excluded from myeloablative regimens were able to tolerate RIC regimens. Retrospective comparisons of patients treated with RIC and myeloablative regimens showed lower nonrelapse mortality but higher relapse risk with RIC; however, overall survivals were similar though a larger fraction of RIC patients had high-risk pretransplant features. Study design weaknesses limit the ability to generalize and apply these results. RIC and myeloablative TBI-based regimens result in durable engraftment of donor stem cells, tolerable toxicity, and acceptable rates of relapse risk and overall survival. Determination of the optimal dose of TBI for allogeneic transplantation is complex and depends on several variables and may vary based on a specific permutation of these variables.

SUMMARY

A broad range of TBI doses for RIC regimens are effective; however, all conclusions are limited by the lack of prospective, randomized trials comparing RIC and myeloablative regimens.

Early outcomes after allogeneic hematopoietic SCT in pediatric patients with hematologic malignancies following single fraction TBI

Fractionated TBI (FTBI) followed by allogeneic hematopoietic SCT results in donor engraftment and improves survival in children with high-risk hematologic malignancies. However, acute toxicities (skin, lung and mucosa) are common after FTBI. Late complications include cataracts, endocrine dysfunction, sterility and impaired neurodevelopment. Instead of FTBI, we used low-dose single fraction TBI (550 cGy) with CY as transplant conditioning for pediatric hematologic malignancies. GVHD prophylaxis included CYA and short-course MTX; methylprednisolone was added for unrelated donor transplants. A total of 55 children in first (40%) or second remission and beyond (60%) underwent transplantation from BM (65%) or peripheral blood; 62% from unrelated donors; 22% were mismatched. Median follow-up was 18.5 months (1-68). Overall survival and disease-free survival at 1 year were 60 and 47%, respectively. Acute toxicities included grade 3-4 mucositis (18%), invasive infections (11%), multiorgan failure/shock (11%), hemolytic anemia (7%), veno-occlusive disease (4%) and renal failure (4%). TRM was 11% at 100 days. Non-relapse mortality was 6% thereafter. Graft rejection occurred in 2%. Three patients (5%) died of GVHD. The regimen was well tolerated even in heavily pretreated children and supported donor cell engraftment; long-term follow up is in progress.

A randomized double-blind trial of hydroxychloroquine for the prevention of chronic graft-versus-host disease after allogeneic peripheral blood stem cell transplantation

Hydroxychloroquine (HCQ) is an immunosuppressive lysosomotropic amine that has activity against graft-versus-host disease (GVHD). In a single-institution phase III trial, 95 recipients of allogeneic peripheral blood stem cell (PBSC) transplantation were randomized to receive, in a double-blind fashion, and in addition to prophylactic cyclosporine A (CSA), HCQ, or placebo starting 21 days pretransplant and continued until day +365. HCQ was very well tolerated and not associated with side effects. Overall, the incidence of acute GVHD (aGVHD) was 59% in both arms, and severe aGVHD occurred in 11% (HCQ) and 14% (placebo) (P = .76). Sixty percent and 78% of patients developed chronic GVHD (cGVHD) in the HCQ and the placebo arms, respectively (P = .15). With a median follow-up of 18 months, relapse-free and overall survivals (OS) were comparable in both groups. In summary, in this randomized trial, the addition of HCQ to single-agent CSA had no effects on aGVHD or cGVHD or survival.

Relapse risk in patients with malignant diseases given allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning

Allogeneic hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning for hematologic malignancies depends on graft-versus-tumor effects for eradication of cancer. Here, we estimated relapse risks according to disease characteristics. Between 1997 and 2006, 834 consecutive patients (median age, 55 years; range, 5-74 years) received related (n = 498) or unrelated (n = 336) HCT after 2 Gy total body irradiation alone (n = 171) or combined with fludarabine (90 mg/m(2); n = 663). Relapse rates per patient year (PY) at risk, corrected for follow-up and competing nonrelapse mortality, were calculated for 29 different diseases and stages. The overall relapse rate per PY was 0.36. Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) in remission (CR), low-grade or mantle cell non-Hodgkin lymphoma (NHL) (CR + partial remission [PR]), and high-grade NHL-CR had the lowest rates (0.00-0.24; low risk). In contrast, patients with advanced myeloid and lymphoid malignancies had rates of more than 0.52 (high risk). Patients with lymphoproliferative diseases not in CR (except Hodgkin lymphoma and high-grade NHL) and myeloid malignancies in CR had rates of 0.26-0.37 (standard risk). In conclusion, patients with low-grade lymphoproliferative disorders experienced the lowest relapse rates, whereas patients with advanced myeloid and lymphoid malignancies had high relapse rates after nonmyeloablative HCT. The latter might benefit from cytoreductive treatment before HCT.

Reduced intensity allogeneic umbilical cord blood transplantation in children and adolescent recipients with malignant and non-malignant diseases

There is a significant amount of morbidity and mortality following myeloablative umbilical cord blood transplantation (UCBT). Reduced intensity (RI) conditioning offers an alternative to myeloablative conditioning before UCBT. We investigated RI-UCBT in 21 children and adolescents with malignant (n=14), and non-malignant diseases (n=7). RI conditioning consisted of fludarabine (150-180 mg/m2) with either busulfan (< or = 8 mg/kg)+rabbit antithymocyte globulin (R-ATG; n=16) or cyclophosphamide+R-ATG+/-etoposide (n=5). Human leukocyte antigen match: 4/6 (n=13), 5/6 (n=5) and 6/6 (n=3). The median total nucleated cell and CD34+ cell dose per kilogram were 3.58 x 10(7) and 2.54 x 10(5), respectively. The median time for neutrophil and platelet engraftment was 17.5 and 52 days, respectively. There were six primary graft failures (chronic myelogenous leukemia (CML), beta-thalassemia, hemophagocytic lymphohistiocytosis (HLH) and myelodysplastic syndrome (MDS)). The probability of developing grade II to grade IV acute graft-versus-host disease (GVHD) and chronic GVHD was 28.6 and 16.7%, respectively. Incidence of transplant-related mortality (TRM) was 14%. The 5 years overall survival (OS) in all patients was 59.8%. The 5 years OS for patients with average versus poor-risk malignancy was 77.8 versus 22.2% (P=0.03). RI-UCBT may result in graft failure in specific high-risk chemo-naïve patients (CML, beta-thalassemia, HLH and MDS), but in more heavily pretreated pediatric and adolescent recipients results in rapid engraftment and may be associated with decreased severe GVHD and TRM.

Long-term follow-up of allogeneic bone marrow transplantation for patients with chronic phase chronic myeloid leukemia prepared with a regimen consisting of cyclophosphamide, cytarabine and single-dose total body irradiation conditioning

We evaluated long-term toxicities and outcomes in 96 patients with chronic phase chronic myeloid leukemia treated with a single bone marrow allograft regimen. Conditioning was cytosine arabinoside, cyclophosphamide (120 mg/kg) and single fraction total body irradiation (500 cGy). Median follow-up was 12.8 years (0.4-19.9 years). Graft failure occurred in one patient, nonfatal veno-occlusive disease in 13 patients (14%). Overall incidences of acute (a) and chronic (c) graft-vs-host disease (GVHD) were 77 and 63%. The 100-day and 1-year transplant-related mortality (TRM) were 1 and 9.2%, respectively, with no change through 5 years. Five- and 10-year event-free survival rates were 56 and 49%, overall survival (OS) rates 72 and 70%, respectively. Forty patients have relapsed: 8 cytogenetic (20%), 10 hematologic (25%) and 22 molecular (55%). Most have been salvaged with donor-leukocyte infusion, second transplants and/or imatinib therapy. Survival was worse for patients transplanted >2 years from diagnosis (10-year OS 56 vs 78%, P=0.01), for patients over 50 years old (10-year OS 44 vs 75%, P=0.05) and for patients without cGVHD (10-year OS 53 vs 86%, P<0.001). This regimen resulted in successful engraftment, low risk of TRM and long-term survival. In an era when imatinib is first line therapy, this regimen offers a potentially low-toxicity, highly successful alternative in the event of poor imatinib response.

Long-term remissions in patients with myelodysplastic syndrome and secondary acute myelogenous leukemia undergoing allogeneic transplantation following a reduced intensity conditioning regimen of 550 cGy total body irradiation and cyclophosphamide

We analyzed outcomes of patients with myelodysplastic syndrome (MDS) or secondary acute myelogenous leukemia (sAML) that were treated at our institution with a reduced intensity conditioning (RIC) regimen of 550-cGy total body irradiation and cyclophosphamide followed by related donor (RD) or unrelated donor (URD) transplantation. Fifty-one consecutive patients with MDS or sAML received this RIC regimen and URD (n = 30) or RD (n = 21) stem cells. Graft-versus-host disease prophylaxis consisted of cyclosporine alone (RD) or with corticosteroids and methotrexate (URD). Median patient age was 44 years. With a median follow-up of 3.7 years after transplantation in the 19 surviving patients (37%), Kaplan-Meier estimates of overall survival were 88%, 46%, 33%, and 11% for patients transplanted with sAML in remission, refractory anemia, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, or sAML refractory/untreated, respectively. Kaplan-Meier estimates of relapse-free survival were 75%, 46%, 33%, and 11%, respectively. Overall, the cumulative incidences of relapse and transplant-related mortality were 27% and 37%, respectively. In patients with MDS, this is an effective RIC regimen for allogeneic transplantation that can be used as an alternative to other RIC or conventional conditioning regimens.

Stem cell transplantation with reduced-intensity conditioning regimens: a review of ten years experience with new transplant concepts and new therapeutic agents

The realization in the 1990s that allogeneic stem cell transplants (SCT) have a potentially curative graft-versus-leukemia (GVL) effect in addition to the antileukemic action of myeloablative conditioning regimens was a major stimulus for the development of reduced-intensity conditioning (RIC) regimens, aimed primarily at securing engraftment to provide the GVL effect, while minimizing regimen-related toxicity. It is now over 10 years since RIC regimens were heralded as a new direction in the field of SCT. Over the last decade much has been learned about the ways in which the conditioning regimen can be tailored to provide adequate immunosuppression, and modulated to deliver a chosen degree of antimalignant treatment. The huge literature of clinical data with RIC transplantation now permits us to more clearly define the success and limitations of the approach. This review examines the origins of RIC SCT, explores the degree to which the initial expectations and purpose of the approach have been realized, and outlines some ways forward for the field.

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.

Evidence for predictive validity of blood assays to evaluate individual radiosensitivity

PURPOSE

An escalation in standard irradiation dose ensuring improved local tumor control is estimated, but this strategy would require the exclusion of the most sensitive individuals from treatment. Therefore, fast and reliable assays for prediction of the individual radiosensitivity are urgently required.

METHODS AND MATERIALS

Seven parameters in lymphocytes of 40 patients with leukemia were analyzed before, during, and after total body irradiation (TBI) and in vitro X-ray irradiation. These were: cell proliferation, nuclear damage, activation of cytokines, and numbers of total leukocytes of CD34+ hematopoietic blood stem cells and of CD4+ and CD8+ lymphocytes. Additionally, antioxidative capacity of blood plasma, uric acid, and hemoglobin levels were measured. Blood samples of 67 healthy donors were used as controls.

RESULTS

In vivo and in vitro irradiations showed comparable results. A dose-response relationship was found for most parameters. Three parameters were associated with severe acute oral mucositis (Grade 3 or 4 vs. Grade 0 to 2): leukocytes fewer than 6200/microL after 4 Gy TBI, a rate of >19% lymphocytes with reduced DNA and protein content ("necroses") after 4 Gy in vitro irradiation, and a small antioxidative capacity in blood plasma (<0.68 mMol) after 8 Gy TBI.

CONCLUSION

Three simple blood assays were associated with oral mucositis that are posed here hypothetically as an early symptom of enhanced radiosensitivity in leukemic patients: leukocyte count, damaged lymphocyte score, and the antioxidative capacity after exposure.

Dose response and factors related to interstitial pneumonitis after bone marrow transplant

PURPOSE

Total body irradiation (TBI) and chemotherapy are common components of conditioning regimens for bone marrow transplantation. Interstitial pneumonitis (IP) is a known regimen-related complication. Using published data of IP in a multivariate logistic regression, this study sought to identify the parameters in the bone marrow transplantation conditioning regimen that were significantly associated with IP and to establish a radiation dose-response function.

METHODS AND MATERIALS

A retrospective review was conducted of articles that reported IP incidence along with lung dose, fractionation, dose rate, and chemotherapy regimen. In the final analysis, 20 articles (n = 1090 patients), consisting of 26 distinct TBI/chemotherapy regimens, were included in the analysis. Multivariate logistic regression was performed to determine dosimetric and chemotherapeutic factors that influenced the incidence of IP.

RESULTS

A logistic model was generated from patients receiving daily fractions of radiation. In this model, lung dose, cyclophosphamide dose, and the addition of busulfan were significantly associated with IP. An incidence of 3%-4% with chemotherapy-only conditioning regimens is estimated from the models. The alpha/beta value of the linear-quadratic model was estimated to be 2.8 Gy. The dose eliciting a 50% incidence, D50, for IP after 120 mg/kg of cyclophosphamide was 8.8 Gy; in the absence of chemotherapy, the estimated D50 is 10.6 Gy. No dose rate effect was observed. The use of busulfan as a substitute for radiation is equivalent to treating with 14.8 Gy in 4 fractions with 50% transmission blocks shielding the lung. The logistic regression failed to find a model that adequately fit the multiple-fraction-per-day data.

CONCLUSIONS

Dose responses for both lung radiation dose and cyclophosphamide dose were identified. A conditioning regimen of 12 Gy TBI in 6 daily fractions induces an IP incidence of about 11% in the absence of lung shielding. Shielding the lung to receive 50% of this dose lowers the estimated incidence to about 2.3%. Because the lungs can be adequately shielded, we recommend against using busulfan as a substitute for fractionated TBI with cyclophosphamide.

Reduced-intensity allogeneic stem cell transplantation in adults and children with malignant and nonmalignant diseases: end of the beginning and future challenges

During the last 10 years, multiple studies using reduced-intensity (RI) conditioning followed by allogeneic stem cell transplantation (AlloSCT) have been reported in adult and, less so, pediatric recipients. RI AlloSCT allegedly eradicates malignant cells through a graft-versus-leukemia/graft-versus-tumor effect provided by alloreactive donor T lymphocytes, natural killer cells, or both. Various studies have clearly demonstrated a graft-versus-leukemia/graft-versus-tumor effect in hematologic malignancies and solid tumors. Acute short-term toxicity, including infection and organ decompensation after myeloablative conditioning therapy, can result in a significant incidence of early transplant-related mortality. More importantly, long-term late effects-including growth retardation, infertility, and secondary malignancies-are major complications after myeloablative conditioning therapy, especially in vulnerable children, who are more susceptible to these complications. Recent results comparing RI conditioning with myeloablative conditioning followed by HLA-matched sibling AlloSCT have demonstrated a significant reduction in use of blood products, risk of infections, transplant-related mortality, length of hospitalization, and feasibility of conditioning therapy in outpatient settings. Despite the success of RI AlloSCT, large prospective randomized multicenter studies are necessary to define the appropriate patient population, optimal conditioning regimens and pretransplantation immunosuppression, role of donor lymphocyte infusions, duration of hospitalization, overall survival, cost-benefit ratio, and differences in long-term effects to evaluate the role of RI AlloSCT more fully. We review the recent experience of RI AlloSCT in adults and children with both malignant and nonmalignant diseases and discuss the challenges for the future.

HLA-matched unrelated donor hematopoietic cell transplantation after nonmyeloablative conditioning for patients with chronic myeloid leukemia

We evaluated 10/10 HLA antigen-matched unrelated hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning with fludarabine 3 x 30 mg/m2 and 2 Gy of total body irradiation as treatment for patients with chronic myeloid leukemia who were ineligible for conventional HCT. Data from 21 consecutive patients in first chronic phase (CP1; n = 12), accelerated phase (AP; n = 5), second CP (CP2; n = 3), and blast crisis (n = 1) were analyzed. Stem cell sources were bone marrow (n = 4) or granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMCs; n = 17). The patient who underwent transplantation in blast crisis died on day 21 (too early to be evaluated for engraftment) from progressive disease. Sustained engraftment was achieved in 5 of 12 patients who underwent transplantation in CP1, 4 of 5 patients who underwent transplantation in AP, and 2 of 3 patients who underwent transplantation in CP2, whereas 9 patients rejected their grafts between 28 and 400 days after HCT. Specifically, 1 of 4 marrow recipients and 10 of 17 G-PBMC recipients achieved sustained engraftment. Graft rejections were nonfatal in all cases and were followed by autologous reconstitution with persistence or recurrence of chronic myeloid leukemia. Seven of 11 patients with sustained engraftment--including all 5 patients in CP1, 2 of 4 patients in AP, and neither of the 2 patients in CP2--were alive in complete cytogenetic remissions 118 to 1205 days (median, 867 days) after HCT. Two of the remaining 4 patients died of nonrelapse causes in complete (n = 1) or major (n = 1) cytogenetic remissions, and 2 died of progressive disease. Further efforts are directed at reducing the risk of graft rejection by exclusive use of G-PBMC and increasing the degree of pretransplantation immunosuppression.

Chronic myeloid leukemia: current application of cytogenetics and molecular testing for diagnosis and treatment

Chronic myeloid leukemia provides an illustrative disease model for both molecular pathogenesis of cancer and rational drug therapy. Chronic myeloid leukemia is a clonal stem cell disease caused by an acquired somatic mutation that fuses, through chromosomal translocation, the abl and bcr genes on chromosomes 9 and 22, respectively. The bcr/abl gene product is an oncogenic protein that localizes to the cytoskeleton and displays an up-regulated tyrosine kinase activity that leads to the recruitment of downstream effectors of cell proliferation and cell survival and consequently cell transformation. Such molecular information on pathogenesis has facilitated accurate diagnosis, the development of pathogenesis-targeted drug therapy, and most recently the application of molecular techniques for monitoring minimal residual disease after successful therapy. These issues are discussed within the context of clinical practice.

Hydroxychloroquine for the prevention of acute graft-versus-host disease after unrelated donor transplantation

Hydroxychloroquine (HCQ) is an immunosuppressive agent that interferes with antigen presentation and with activity against graft-versus-host disease (GVHD). In a phase II trial assessing the GVHD prophylactic effects of HCQ, 51 consecutive unrelated donor transplant recipients received HCQ in addition to cyclosporin A, methylprednisolone, and methotrexate. HCQ was initiated on pretransplantation day -21 at 800 mg/d and continued until day +100 after transplantation. HCQ was extremely well tolerated and was not associated with side effects. Pharmacokinetic analyses demonstrated large inter- and intrapatient variability. The addition of HCQ did not affect posttransplantation immune recovery. Grade II to IV acute GVHD was observed in 56% of patients, and grade III and IV GVHD was observed in 17%. Day +100 mortality was 22%. When compared with a matched cohort of patients reported to the International Bone Marrow Transplant Registry, patients receiving HCQ had comparable cumulative incidences of grade II to IV acute GVHD. However, lower incidences of grades III and IV GVHD and better GVHD-free survival were observed in HCQ-treated patients (P =.01). We conclude that prophylactic HCQ is well tolerated and associated with a low incidence of severe acute GVHD. An ongoing placebo-controlled randomized trial will further determine what role HCQ plays in preventing GVHD after allografting.

Reduced-intensity conditioning followed by allogeneic hematopoietic cell transplantation in myeloid diseases

Within the past years, reduced or modified doses of chemotherapy or radiotherapy have been widely studied for conditioning before allogeneic hematopoietic cell transplantation in patients with myeloid leukemia not eligible for conventional transplantation. The main goal was to reduce the substantial treatment-related mortality in this patient population while preserving the potential curative graft-versus-leukemia effect. This review summarizes results of published trials using reduced-intensity conditioning (RIC) in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), chronic myeloid leukemia (CML), and myelofibrosis. In most of the published trials conditioning contained fludarabine (90-180 mg/m(2)) in combination with busulfan (4 x 10 mg/kg), melphalan (90-140 mg/m(2)), or 2-5 Gy total body irradiation (TBI). Peripheral blood hematopoietic stem cells from related or unrelated donors were used as graft source in most of the studies. Post-transplantation immunosuppression consisted of cyclosporine combined with methotrexate or mycophenolate mofetil. Although the majority of the patients were above the age of 50 years, early treatment-related mortality was rather low. Nevertheless, the rate of clinically significant graft-versus-host disease (GVHD) seemed to be comparable to conventional transplants in most of the protocols. The outcome differed between trials, but diagnosis and disease status pre-transplant significantly influenced outcome. In summary, this approach is feasible and provides access to the curative potential of allogeneic stem cell transplantation for patients with higher age or comorbidities. Since the majority of the reports included heterogeneous patient populations, mostly with a short follow-up, more and specifically randomized studies are needed to define the role of RIC before allogeneic hematopoietic cell transplantation.

Hematopoietic cell transplantation in the treatment of leukemia

OBJECTIVES

To review the current evidence regarding the role and benefits of hematopoietic cell transplantation (HCT) in leukemia.

DATA SOURCES

Review articles, original articles, internet web sites, and books.

CONCLUSION

HCT is a potentially curative treatment modality for patients with hematologic malignancies such as leukemia.

IMPLICATIONS FOR NURSING PRACTICE

Nurses working with patients undergoing HCT need awareness of the type of leukemia, source of the hematopoietic cell product, type of preparative regimen used, and the complications of the procedure will enable nurses to educate and intervene with patients and their family members throughout the transplant trajectory.

Reduced intensity preparative regimens for allogeneic hematopoietic stem cell transplantation: a single center experience

According to recent reports, fast engraftment with minimal transplant-related toxicity and mortality (TRT, TRM) can be achieved by using reduced-intensity preparative regimens in allogeneic hematopoietic stem cell transplantation (HSCT). We report our experience with related (39%) and unrelated (61%) HSCT in 44 high risk patients (AML, ALL, CML, CLL) receiving either busulfan/fludarabine or busulfane/fludarabine/ATG or TBI/fludarabine as reduced-intensity preparative regimens. Organ toxicity was minimal with mild mucositis and no major bleeding. Acute GVHD was recorded in 64% of the patients. Twenty-three patients achieved complete remission after transplantation, and complete chimerism was obtained in all patients with stable engraftment (35 patients). Twenty-nine patients died: 15 due to relapse/progression, 14 due to TRM. Survival with median follow-up of 18.5 months was significantly better in patients with matched related transplants compared to patients with other transplants. However, there was no difference between related and unrelated transplants with regard to engraftment, TRM and GVHD. In conclusion, our results in high-risk patients transplanted in CR or with smoldering leukemia from a related donor are encouraging, although a longer follow-up and a larger group of patients is needed in order to evaluate the role of different reduced-intensity preparative regimens in unrelated and related HSCT.

Long-term follow-up of allogeneic bone marrow transplantation after reduced-intensity conditioning in patients with chronic myelogenous leukemia in the chronic phase

Although allogeneic transplantation is a curative therapy for chronic myelogenous leukemia (CML), treatment-related mortality is still a major cause of death after transplantation, especially in older patients. We investigated the safety and efficacy of reduced-intensity conditioning consisting of low-dose (600 cGy) total body irradiation and cytosine arabinoside (1 g/m2) together with a continuous infusion of granulocyte colony-stimulating factor and cyclophosphamide (120 mg/kg) in patients with CML in the chronic phase. Fractionated splenic irradiation (5 Gy) was also administered as part of the conditioning treatment. Eight patients older than 40 years underwent allogeneic bone marrow transplantation from an HLA-matched sibling following this conditioning. Regimen-related toxicities (equal to or greater than grade III) were not observed. Rapid restoration of 100% donor chimerism was confirmed by fluorescence in situ hybridization methods in 5 sex-mismatched transplant recipients. One patient died from severe acute graft-versus-host disease and another from Pneumocystis carinii pneumonia early in the course of transplantation. A sustained engraftment was achieved in 5 long-term survivors; in 1 case, the graft was rejected but the Philadelphia chromosome and BCR/ABL-negative autologous hemopoiesis were restored. After a minimum follow-up period of 60 months, 6 patients, including the patient with restored autologous hemopoiesis, were still alive and in remission with 100% donor chimerism. Six years after the transplantation, 1 patient experienced a cytogenetic relapse, which was successfully treated with donor lymphocyte infusions. In summary, this reduced-intensity conditioning resulted in a cure with markedly reduced regimen-related toxicities in this relatively older cohort of patients with CML.

Chronic lymphocytic leukemia

Historically, treatment of chronic lymphocytic leukemia (CLL) essentially had been palliative. During the past two decades, effective new therapies for the treatment of CLL have emerged. The advent of fludarabine, a purine analog with activity against chlorambucil-resistant CLL, showed promising results with high response rates in previously untreated patients. These improvements in response and delays in disease progression have not translated into a survival benefit, indicating that chlorambucil may be the preferred first-line therapy when treatment is indicated. Allogeneic hematopoietic stem cell transplantation, by combining the cytoreductive effects of conditioning with a potent graft-versus-tumor effect, is the only treatment modality with the prospect of cure for patients with CLL. However, conventional hematopoietic stem cell transplantation can be offered only to select patients with CLL because of older age and comorbid conditions. Novel methods of transplantation exploiting the graft-versus-leukemia effect while reducing the toxicity of the pretransplant conditioning are promising approaches that may enable more patients to benefit from this therapy. Monoclonal antibodies such as rituximab or alemtuzumab (Campath-1H; llex Pharmaceuticals, San Antonio, TX) are agents with activity in untreated and resistant CLL. Efforts are being focused on combining these monoclonal antibodies with chemotherapy and the development of rationally designed drugs.