|
|||||
|
|
||||||
Originally published as JCO Early Release 10.1200/JCO.2005.02.0057 on November 28 2005 © 2005 American Society of Clinical Oncology. Allogeneic Stem-Cell Transplantation Using a Reduced-Intensity Conditioning Regimen Has the Capacity to Produce Durable Remissions and Long-Term Disease-Free Survival in Patients With High-Risk Acute Myeloid Leukemia and MyelodysplasiaFrom the Department of Hematology, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom Address reprint requests to Charles Craddock, MD, Department of Hematology, Queen Elizabeth Hospital, Edgbaston, Birmingham B15 2TH, United Kingdom; e-mail: charles.craddock{at}uhb.nhs.uk
PURPOSE: The toxicity of allogeneic stem-cell transplantation can be substantially reduced using a reduced-intensity conditioning (RIC) regimen. This has increased the proportion of patients with myeloid malignancies eligible for allogeneic transplantation. However, the capacity of RIC allografts to produce durable remissions in patients with acute myeloid leukemia (AML) and myelodysplasia (MDS) has not yet been defined, and consequently, the role of RIC allografts in the management of these diseases remains conjectural. PATIENTS AND METHODS: Seventy-six patients with high-risk AML or MDS received an allograft using a fludarabine/melphalan RIC regimen incorporating alemtuzumab. The median age of the cohort was 52 years (range, 18 to 71 years). RESULTS: The 100-day transplantation-related mortality rate was 9%, and no patient developed greater than grade 2 graft-versus-host disease. With a median follow-up of 36 months (range, 13 to 70 months), 27 patients were alive and in remission, with 3-year actuarial overall survival (OS) and disease-free survival (DFS) rates of 41% and 37%, respectively. The 3-year OS and DFS rates of patients with AML in complete remission at the time of transplantation were 48% and 42%, respectively. Disease relapse was the most common cause of treatment failure and occurred at a median time of 6 months after transplantation. All but one patient destined to relapse did so within 24 months of transplantation. CONCLUSION: The extended follow-up in this series identifies a high risk of early disease relapse but provides evidence that RIC allografts can produce sustained DFS in a significant number of patients with AML who would be ineligible for allogeneic transplantation with myeloablative conditioning.
The incidence of acute myeloid leukemia (AML) and myelodysplasia (MDS) in adults increases sharply with age.1 Despite improvements in chemotherapy and supportive care, the outlook for patients 50 years and older is dismal, and new treatment strategies are needed.2-4 In younger patients, allogeneic stem-cell transplantation (SCT) has been shown to decrease the risk of disease relapse when compared with chemotherapy and is now established as the treatment of choice in eligible patients with high-risk AML and MDS.5 Until recently, a myeloablative conditioning regimen has been considered a prerequisite for successful allogeneic SCT both because of its antitumor activity and also because of its perceived role in securing durable donor stem-cell engraftment.6 However, the toxicity of myeloablative preparative regimens has precluded the extension of the potentially curative effect of allogeneic SCT to older patients with myeloid malignancies, limiting treatment options even further in this population of patients at high risk of disease relapse.7 Accumulating evidence that the donor-derived immune system exerts a potent antileukemic effect after allograft has led to the development of reduced-intensity conditioning (RIC) regimens that are designed to produce durable donor engraftment of allogeneic stem cells and provide a platform for an immunologically mediated graft-versus-leukemia (GVL) effect with less attendant toxicity.8-10 RIC regimens have been remarkably successful in reducing transplantation-related mortality (TRM), permitting allogeneic SCT to be performed in older patients in whom it was previously contraindicated. However, although a number of reports have confirmed that such regimens allow older patients with high-risk AML or MDS to receive an allograft with relative safety, the follow-up in these studies has been short.11-14 Thus, it has not been possible to assess whether RIC regimens have the capacity to produce long-term disease-free survival (DFS) in patients with high-risk AML and MDS, and consequently, the role of RIC regimens in patient management remains controversial. This article reports the outcome of patients with high-risk AML and MDS who underwent allogeneic transplantation using a RIC regimen incorporating alemtuzumab. Extended follow-up of this cohort has identified that durable remissions are achievable in a significant proportion of patients with high-risk AML. Disease relapse remains the major cause of treatment failure and occurs in the first year after transplantation in the majority of patients. These data demonstrate that RIC allografts possess the capacity to deliver long-term DFS in patients with high-risk AML.
Patient Characteristics This article reports the outcome of 76 patients who received an alemtuzumab-containing RIC allograft for high-risk AML or MDS at one of 12 transplantation centers in the United Kingdom from 1998 to 2004. Of the 76 patients in this study, 11 were reported previously and are now included here with extended follow-up.15,16 Detailed characteristics are listed in Table 1. The median age was 52 years (range, 18 to 71 years). There were 46 men and 30 women; 41 patients received an allograft from an unrelated donor, and 35 received an allograft from a matched sibling donor. Twenty-four patients younger than 45 years old received an RIC regimen rather than a myeloablative regimen because of poor performance status (n = 16), previous SCT (n = 7; autologous SCT in five patients and myeloablative allograft in two patients), or patient preference (n = 1). At the time of transplantation, 42 patients with AML were in complete remission (CR), of whom 22 were in first CR (CR1) and 20 were in second CR (CR2) or greater. Patients who received an allograft in CR1 were classified as being at a high risk of treatment failure after conventional chemotherapy because of a diagnosis of therapy-related or secondary AML, the presence of an adverse karyotype at diagnosis,4 or the development of prolonged aplasia after chemotherapy.17 In patients who underwent transplantation in CR2, the median duration of CR1 was 21 months (range, 18 to 60 months). Of the remaining patients, 14 had relapsed/refractory disease AML, and 20 had MDS (refractory anemia, n = 8; refractory anemia with ringed sideroblasts, n = 2; and refractory anemia with excess of blasts, n = 10).
Patients were enrolled after approval from the local research ethics committee, and written informed consent was obtained before conditioning. Unrelated donor selection was performed according to published criteria and involved serologic typing for HLA-A and HLA-B antigens and molecular typing for HLA-C, DRB1, and DQB1, or full molecular typing for HLA-A, HLA-B, HLA-C, DRB1, and DQB1. Volunteer unrelated donors gave written consent through the current accepted standards and procedures of the relevant registry.
Transplantation Details and Monitoring
Outcomes and Statistical Analysis
Engraftment and Chimerism Analysis Seventy-four patients demonstrated durable neutrophil and platelet engraftment. Neutrophil engraftment occurred at a median of 13 days after transplantation (range, 7 to 27 days), and platelet engraftment occurred at a median of 13 days (range, 6 to 66 days). Chimerism studies confirmed more than 95% donor engraftment by day 60 in the 19 patients in whom it was available. Primary graft failure occurred in two patients transplanted from an unrelated donor; one patient received bone marrow mononuclear cells, and one patient received PBSC (both patients received more than 2 x 106 CD34+ cells/kg). Cryopreserved autologous marrow was used to rescue one patient who subsequently experienced disease relapse. The other patient received a second transplantation from a different unrelated donor but subsequently died of grade 4 GVHD.
Survival Analysis
In a multivariate setting, Cox regression analysis demonstrated prognostic significance of disease stage at the time of transplantation, with improved DFS in patients with AML in CR at the time of transplantation (hazard ratio = 2.03; 95% CI, 1.02 to 4.07). Disease status at transplantation was only of borderline significance for OS (hazard ratio = 1.92; 95% CI, 0.95 to 3.88). No other variables were of prognostic significance for either DFS or OS in multivariate analysis.
GVHD, TRM, and Death
Disease Relapse
Nine patients received donor lymphocyte infusion (DLI) from their sibling (n = 8) or unrelated donor (n = 1) at a dose of 1 to 10 x 106 CD3+ cells/kg commencing a median of 258 days (range, 91 to 681 days) after transplantation. Three patients received DLI (one with prior cytoreduction) as treatment of hematologic relapse, five patients received DLI for the management of mixed chimerism, and one patient received DLI for the treatment of persistent cytopenia in the absence of evidence of disease relapse. No disease response was observed in patients with relapsed disease. All patients receiving DLI for mixed chimerism achieved full donor hematopoiesis and remain in sustained CR.
Patient age is one of the most important determinants of outcome in adults with AML. Less than 25% of patients with AML older than 50 years old treated with chemotherapy alone survive long term.2,4,22 The outlook for patients with relapsed disease is equally poor, and remissions achieved using chemotherapy in relapsed AML are rarely durable.23,24 Therefore, the opportunity provided by RIC regimens to extend the curative potential of allogeneic SCT to this population of patients is of considerable interest. However, although a number of studies have confirmed that RIC regimens permit transplantation of sibling or unrelated donor stem cells with acceptable toxicity in patients up to the age of 70 years,11-14 the ability of RIC regimens to confer long-term DFS in patients with high-risk AML or MDS has not previously been demonstrated. In this series, the 3-year DFS rates observed for patients undergoing transplantation for AML in CR1 or CR2 using an RIC regimen are comparable with the rates obtained using a myeloablative regimen.5,25 Of note, the 3-year survival rate for comparable patients treated with chemotherapy alone would be expected to be in the range of 15% to 25%.4,22-24 Relapse was the major cause of treatment failure after RIC allograft and occurred early. All but one of the patients who experienced relapse did so within 24 months of transplantation. Thus the kinetics of disease relapse after a RIC allograft are similar to those observed when patients are transplanted using a more intensive myeloablative conditioning regimen, in which patients are exposed to the combined antileukemic effect of myeloablation and a GvL effect.26,27 Therefore, it is reasonable to conclude that the probability of relapse is low for patients in this series who are alive and free of leukemia more than 2 years after an RIC allograft. Taken together, our data demonstrate that RIC regimens have the capacity to deliver long-term DFS in a proportion of patients with high-risk AML. Consequently, a prospective comparison of RIC allogeneic SCT is now warranted in older patients (and patients with significant comorbidities) with AML in first CR. The low nonrelapse mortality using this preparative regimen is notable because all patients were considered ineligible for a myeloablative allograft on the grounds of comorbidity or age, more than half received an unrelated donor transplantation, and a number had undergone a previous SCT. This study confirms previous reports that the incorporation of alemtuzumab into the preparative regimen is associated with a low incidence of severe acute and chronic GVHD.12,15,16 Strategies that reduce the risk of GVHD play a major role in limiting the toxicity of reduced-intensity allografts because T-cellreplete RIC transplantations have been reported to be associated with a substantial rate of GVHD-related mortality and morbidity, particularly in recipients of unrelated donor grafts.13,14,29 CMV reactivation remains a significant complication of allogeneic SCT using this conditioning regimen. Because stem-cell dose is an important determinant of immune reconstitution after allogeneic SCT, it will be important to assess whether the increased availability of PBSC harvests from unrelated donors reduces the incidence of CMV viremia.30 The major cause of treatment failure after allogeneic SCT for AML using an RIC regimen is disease relapse. This parallels results achieved using the myeloablative conditioning regimen in high-risk AML, in which relapse rates range from 30% to 60%.25,31,32 It might be expected that the intense degree of T-cell depletion achieved using alemtuzumab would increase the risk of disease relapse, particularly in patients receiving an RIC regimen. However, at present, the relapse rates observed in this study do not seem to be substantially higher than the rates in patients receiving T-cell replete RIC allografts.13,14,29,33,34 In addition, remission inversion was produced in a significant number of patients who received an allograft in CR2 using this alemtuzumab-containing regimen. Although pharmacokinetic data from patients treated with in vivo alemtuzumab have indicated delayed recovery of the T-cell compartment after transplantation,36 our results imply the persistence of a potent GVL effect. Recent data are consistent with the presence of a significant GVL effect in AML exerted by both alloreactive T and natural killer (NK) cells,9and rapid reconstitution of the NK cell repertoire is now known to occur after transplantation in the HLA-matched setting.35 In addition, early withdrawal of cyclosporine after an RIC allograft may also play a role in permitting the rapid expansion of both T lymphocytes and NK cells. Further elucidation of the mechanisms underlying eradication of the leukemic clone after an RIC allograft will be important to develop strategies to reduce the risk of disease relapse. The observation in this article that the great majority of patients who are destined to relapse do so in the first 12 months after transplantation defines the period when regular monitoring for evidence of disease recurrence is warranted and also identifies a relatively narrow window in which intervention aimed at reducing the risk of relapse should be targeted. The serial use of lineage-specific chimerism to monitor the proportion of donor T cells after allograft may identify patients at risk of relapse and allow the early use of prophylactic DLI with the aim of securing full donor T-cell chimerism. Because the incidence of GVHD with this regimen is low, such a strategy is feasible, although the risk of severe GVHD after DLI, particularly when it is administered in the first few months after transplantation, may limit the effectiveness of this approach. Combining biologically targeted therapies, such as flt-3 or farnesyltransferase inhibitors, with an RIC allograft may be an attractive strategy, allowing DLI administration to be delayed in certain biologically defined patient subgroups. Alternatively, the use of technology, such as radioimmunotherapy, to intensify the antileukemic activity of the preparative regimen without increasing toxicity may be of value.37 Our study and other studies indicate that RIC allografts are of little value in patients with a significant disease burden at the time of transplantation,28 and by extension, it is possible that the relapse risk in patients who received an allograft in CR may be determined by levels of occult residual disease at the time of transplantation. The use of newer techniques, such as multiparametric flow cytometry, to study minimal residual disease will help explore this hypothesis further and may identify a role for more intensive cytoreduction before transplantation in patients in morphologic CR. In summary, the ability of allogeneic SCT using an alemtuzumab-containing RIC regimen to produce sustained remissions in patients with AML represents a potential advance in the curative options available in this disease and provides a basis for the further development of immunotherapeutic strategies in patients currently not eligible for myeloablative transplantations.
The author or immediate family members indicated a financial interest. No conflict exists for drugs or devices used in a study if they are not being evaluated as part of the investigation. For a detailed description of the disclosure categories, or for more information about ASCOs conflict of interest policy, please refer to the Author Disclosure Declaration and the Disclosures of Potential Conflicts of Interest section in Information for Contributors.
Dollar Amount Codes (A) < $10,000 (B) $10,000-99,999 (C)
We thank the data managers at participating transplantation centers for their contribution to this work.
S.T. and C.C. contributed equally to this article. Authors' disclosures of potential conflicts of interest are found at the end of this article.
1. Henderson SH: Acute leukemia: General considerations, in Williams WJ, Beutler E, Erslav HA, et al (eds): Hematology (ed 4). New York, NY, McGraw Hill, 1990, p 237 2. Ryan DH, Kopecky KJ, Head D, et al: Analysis of treatment failure in acute nonlymphocytic leukemia patients over fifty years of age: A Southwest Oncology Group study. Am J Clin Oncol 15:69-75, 1992[Medline] 3. Leith CP, Kopecky KJ, Godwin J, et al: Acute myeloid leukemia in the elderly: Assessment of multidrug resistance (MDR) and cytogenetics distinguishes biologic subgroups with remarkably distinct responses to standard chemotherapy: A Southwest Oncology Group study. Blood 89:3323-3329, 1997 4. Grimwade D, Walker H, Harrison G, et al: The predictive value of hierarchical cytogenetic classification in older adults with acute myeloid leukemia (AML): Analysis of 1065 patients entered into the United Kingdom Medical Research Council AML11 trial. Blood 98:1312-1320, 2001 5. Suciu S, Mandelli F, de Witte T, et al: Allogeneic compared with autologous stem cell transplantation in the treatment of patients younger than 46 years with acute myeloid leukemia (AML) in first complete remission (CR1): An intention-to-treat analysis of the EORTC/GIMEMA AML-10 trial. Blood 102:1232-1240, 2003 6. Thomas ED, Storb R, Clift RA, et al: Bone marrow transplantation. N Engl J Med 292:832-843, 1975[Medline] 7. Jemal A, Thomas A, Murray T, et al: Cancer statistics. CA Cancer J Clin 52:23-47, 2002 8. Horowitz MM, Gale RP, Sondel PM, et al: Graft-versus-leukemia reactions after bone marrow transplantation. Blood 75:555-562, 1990 9. Barrett AJ, Rezvani K, Solomon S, et al: New developments in allotransplant immunology, in Broudy VC, Prchal JT, Tricot GJ (eds): Hematology. Washington, DC, American Society of Hematology, 2003, pp 350-371 10. Maloney DG, Sandmaier M, Mackinnon S, et al: Non-myeloablative transplantation, in Broudy VC, Abkowitz JL, Vose JM (eds): Hematology. Washington, DC, American Society of Hematology, 2002, pp 392-401 11. Giralt S, Thall PF, Khouri I, et al: Melphalan and purine analog-containing preparative regimens: Reduced-intensity conditioning for patients with hematologic malignancies undergoing allogeneic progenitor cell transplantation. Blood 97:631-637, 2001 12. Ho AY, Pagliuca A, Kenyon M, et al: Reduced-intensity allogeneic haematopoietic stem cell transplantation for myelodysplastic syndrome and acute myeloid leukaemia with multilineage dysplasia using fludarabine, busulphan and alemtuzumab (FBC) conditioning. Blood 104:1616-1623, 2004 13. Wong R, Giralt SA, Martin T, et al: Reduced-intensity conditioning for unrelated donor hematopoietic stem cell transplantation as treatment for myeloid malignancies in patients older than 55 years. Blood 102:3052-3059, 2003 14. Feinstein LC, Sandmaier BM, Hegenbart U, et al: Non-myeloablative allografting from human leukocyte antigen-identical sibling donors for treatment of acute myeloid leukaemia in first complete remission. Br J Haematol 120:281-288, 2003[CrossRef][Medline] 15. Kottaridis PD, Milligan DW, Chopra R, et al: In vivo CAMPATH-1H prevents graft-versus-host disease following nonmyeloablative stem-cell transplantation. Blood 96:2419-2425, 2000 16. Chakraverty R, Peggs K, Chopra R, et al: Limiting transplantation-related mortality following unrelated donor stem cell transplantation by using a nonmyeloablative conditioning regimen. Blood 99:1071-1078, 2002 17. Cheson BD, Bennett JM, Kopecky KJ, et al: Revised recommendations of the International Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia. J Clin Oncol 21:4642-4649, 2003 18. Kaplan EL, Meier P: Non parametric estimation from incomplete observations. J Am Stat Assoc 53:457-481, 1958[CrossRef] 19. Peto R, Pike M, Armitage P: Design and analysis of randomized clinical trials requiring prolonged observation of each patient. Br J Cancer 35:1-39, 1977[Medline] 20. Cox D: Regression models and life tables. J R Stat Soc B 34:187-220, 1972 21. Przepiorka D, Weisdorf D, Martin P, et al: Consensus Conference on Acute GVHD Grading. Bone Marrow Transplant 15:825-828, 1995[Medline] 22. Taylor PR, Reid MM, Stark AN, et al: De novo acute myeloid leukaemia in patients over 55-years-old: A population-based study of incidence, treatment and outcomeNorthern Region Haematology Group. Leukemia 9:231-237, 1995[Medline] 23. Martino R, Guardia R, Altes A, et al: Time sequential chemotherapy for primary refractory or relapsed adult acute myeloid leukemia: Results of the phase II GIMEMA protocol. Haematologica 84:226-230, 1999 24. Leopold LH, Willemze R: The treatment of acute myeloid leukemia in first relapse: A comprehensive review of literature. Leuk Lymphoma 43:1715-1727, 2002[CrossRef][Medline] 25. Loberiza F Jr: Report on state of the art in blood and marrow transplantation. IBMTR/ABMTR Newsletter 10:7-21, 2003 26. Frassoni F, Labopin M, Gluckman E, et al: Are patients with acute leukaemia, alive and well 2 years post bone marrow transplantation cured? A European surveyAcute Leukaemia Working Party of the European Group for Bone Marrow Transplantation (EBMT). Leukemia 8:924-928, 1994[Medline] 27. Powles R, Singhal S, Treleaven J, et al: Identification of patients who may benefit from prophylactic immunotherapy after bone marrow transplantation for acute myeloid leukemia on the basis of lymphocyte recovery early after transplantation. Blood 91:3481-3486, 1998 28. Sayer HG, Kroger M, Beyer J, et al: Reduced intensity conditioning for allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia: Disease status by marrow blasts is the strongest prognostic factor. Bone Marrow Transplant 31:1089-1095, 2003[CrossRef][Medline] 29. de Lima M, Couriel D, Thall PF, et al: Once daily intravenous busulfan and fludarabine: Clinical and pharmacokinetic results of a myeloablative, reduced toxicity conditioning regimen for allogeneic stem cell transplantation in AML and MDS. Blood 104:857-864, 2004 30. Trenschel R, Ross S, Husing J, et al: Reduced risk of persisting cytomegalovirus pp65 antigenemia and cytomegalovirus interstitial pneumonia following allogeneic PBSCT. Bone Marrow Transplant 25:665-672, 2000[CrossRef][Medline] 31. Champlin R, Schmitz N, Horowitz M, et al: Blood stem cells compared with bone marrow as a source of hematopoietic cells for allogeneic transplantation. Blood 95:3702-3709, 2000 32. Remberger M, Ringdén O, Blau I, et al: No difference in graft-versus-host disease, relapse, and survival comparing peripheral stem cells to the bone marrow using unrelated donors. Blood 98:1739-1745, 2001 33. Taussig DC, Davies AJ, Cavenagh JD, et al: Durable remissions of myelodysplastic syndrome and acute myeloid leukemia after reduced-intensity allografting. J Clin Oncol 21:3060-3065, 2003 34. de Lima M, Anagnostopoulos A, Munsell M, et al: Nonablative versus reduced-intensity conditioning regimens in the treatment of acute myeloid leukemia and high-risk myelodysplastic syndrome: Dose is relevant for long-term disease control after allogeneic hematopoietic stem cell transplantation. Blood 104:865-872, 2004 35. Shilling HG, McQueen KL, Cheng NW, et al: Reconstitution of NK cell receptor repertoire following HLA-matched hematopoietic cell transplantation. Blood 101:3730-3740, 2003 36. Morris C, Rebello P, Thomson KJ, et al: Pharmacokinetics of alemtuzumab used for in vivo and in vitro T-cell depletion in allogeneic transplantations: Relevance for early adoptive immunotherapy and infectious complications. Blood 102:404-406, 2003 37. Mulford DA, Jurcic MG: Antibody-based treatment of acute myeloid leukaemia. Expert Opin Biol Ther 4:95-105, 2004[CrossRef][Medline] Submitted March 22, 2005; accepted August 16, 2005.
This article has been cited by other articles:
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||
|
Copyright © 2005 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|