Current Clinical Trials

Current approaches to postremission therapy for adult acute lymphoblastic leukemia (ALL) include short-term, relatively intensive chemotherapy followed by longer-term therapy at lower doses (maintenance), high-dose marrow-ablative chemotherapy or chemoradiation therapy with allogeneic stem cell rescue (alloBMT), and high-dose therapy with autologous stem cell rescue (autoBMT). Several trials, including a Cancer and Leukemia Group B study (CALGB-8811), of aggressive postremission chemotherapy for adult ALL now confirm a long-term disease-free survival rate of approximately 40%.[1-5] In the latter two series, especially good prognoses were found for patients with T-cell lineage ALL, with disease-free survival rates of 50% to 70% for patients receiving postremission therapy. These series represent a significant improvement in disease-free survival rates over previous, less intensive chemotherapeutic approaches. In contrast, poor cure rates were demonstrated in patients with Philadelphia chromosome (Ph1)-positive ALL, B-cell lineage ALL with an L3 phenotype (surface immunoglobulin positive), and B-cell lineage ALL characterized by t(4;11). Administration of the newer dose-intensive schedules can be difficult and should be performed by physicians experienced in these regimens at centers equipped to deal with potential complications. Studies in which continuation or maintenance chemotherapy were eliminated had outcomes inferior to those with extended treatment durations.[6,7] Imatinib has been incorporated into maintenance regimens in patients with Ph1-postive ALL.[8-10]

AlloBMT results in the lowest incidence of leukemic relapse, even when compared with a bone marrow transplant from an identical twin (syngeneic BMT). This finding has led to the concept of an immunologic graft-versus-leukemia effect similar to graft-versus-host disease (GVHD). The improvement in disease-free survival in patients undergoing alloBMT as primary postremission therapy is offset, in part, by the increased morbidity and mortality from GVHD, veno-occlusive disease of the liver, and interstitial pneumonitis.[11]

The results of a series of retrospective and prospective studies published between 1987 and 1994 suggest that alloBMT or autoBMT as postremission therapy offer no survival advantage over intensive chemotherapy, except perhaps for patients with high risk or Ph1 positive ALL.[12-15] The use of alloBMT as primary postremission therapy is limited by both the need for an HLA-matched sibling donor and the increased mortality from alloBMT in patients in their fifth or sixth decades. The mortality from alloBMT using an HLA-matched sibling donor in these studies ranged from 20% to 40%.

Following on the results of these earlier studies, the International ALL Trial (ECOG-2993) was launched as an attempt to examine the role of transplant as postremission therapy for ALL more definitively and accrued patients from 1993 to 2006.[16] Patients with Ph1 negative ALL between the ages of 15 to 59 received identical multiagent induction therapy resembling previously published regimens.[1-3] Patients in remission were then eligible for HLA typing; patients with a fully matched sibling donor underwent alloBMT as consolidation. Those patients lacking a donor were randomly assigned to receive either an autoBMT or maintenance chemotherapy. The primary outcome measured was overall survival (OS), with event-free survival, relapse rate, and nonrelapse mortality as secondary endpoints. A total of 1,929 patients were registered and stratified according to age, white blood cell count, and time-to-remission. High-risk patients were defined as those having a high white blood cell count at presentation or those older than age 35. Ninety percent of patients in this study achieved remission after induction therapy. Of these patients, 443 were found to have an HLA-identical sibling, 310 of whom underwent alloBMT. For the 456 patients in remission who were eligible for transplant but lacked a donor, 227 received chemotherapy alone, while 229 underwent an autoBMT. By donor-to-no-donor analysis, standard risk ALL patients with an HLA-identical sibling had a 5-year OS of 53% compared with 45% for patients lacking a donor (P = .01). In subgroup analysis, the advantage for patients with donors remained significant for patients with standard risk ALL (OS = 62% vs. 52%; P = .02). For patients with high-risk disease (age older than 35 or high white blood cell count), the difference in OS was 41% versus 35% (donor vs. no donor), but was not significant (P = .2). Relapse rates were significantly lower (P < .00005) for both standard and high-risk patients with HLA-matched donors. In contrast to alloBMT, autoBMT was less effective than maintenance chemotherapy as postremission treatment (5-year OS = 46% for chemotherapy vs. 37% for autoBMT; P = .03). The results of this trial seem to confirm the existence of a graft versus leukemia effect for adult Ph1 negative ALL and support the use of sibling donor alloBMT as the consolidation therapy providing the greatest chance for long term survival for standard risk adult ALL in first remission.[16][Level of evidence: 2A] The results also suggest that in the absence of a sibling donor, maintenance chemotherapy is preferable to autoBMT as postremission therapy.[16][Level of evidence: 2A]

The use of alloBMT as primary postremission therapy is limited both by the need for an HLA-matched sibling donor and by the increased mortality from alloBMT in patients in their fifth or sixth decade. The mortality from alloBMT using an HLA-matched sibling donor ranges from 20% to 40%, depending on the study. The use of matched unrelated donors for alloBMT is currently under evaluation but, because of its current high treatment-related morbidity and mortality, is reserved for patients in second remission or beyond. The dose of total body radiation therapy administered is associated with the incidence of acute and chronic GVHD and may be an independent predictor of leukemia-free survival.[17][Level of evidence: 3iiB]

Aggressive cyclophosphamide-based regimens similar to those used in aggressive non-Hodgkin lymphoma have shown improved outcome of prolonged disease-free status for patients with B-cell ALL (L3 morphology, surface immunoglobulin positive).[18] Retrospectively reviewing three sequential cooperative group trials from Germany, Hoelzer and colleagues found a marked improvement in survival, from zero survivors in a 1981 study that used standard pediatric therapy and lasted 2.5 years, to a 50% survival rate in two subsequent trials that used rapidly alternating lymphoma-like chemotherapy and were completed within 6 months. Aggressive CNS prophylaxis remains a prominent component of treatment. This report, which requires confirmation in other cooperative group settings, is encouraging for patients with L3 ALL. Patients with surface immunoglobulin but L1 or L2 morphology did not benefit from this regimen. Similarly, patients with L3 morphology and immunophenotype but unusual cytogenetic features were not cured with this approach. A white blood cell count of less than 50,000 per microliter predicted improved leukemia-free survival in univariate analysis. Because the optimal postremission therapy for patients with ALL is still unclear, participation in clinical trials should be considered. (Refer to the B-cell (Burkitt) lymphoma section in the PDQ summary on Adult Non-Hodgkin Lymphoma Treatment for more information.)

Standard treatment options for central nervous system (CNS) prophylaxis:

The early institution of CNS prophylaxis is critical to achieve control of sanctuary disease. Some authors have suggested that there is a subgroup of patients at low-risk for CNS relapse for whom CNS prophylaxis may not be necessary. However, this concept has not been tested prospectively.[19]

1. Cranial radiation therapy plus intrathecal (IT) methotrexate.
2. High-dose systemic methotrexate and IT methotrexate without cranial radiation therapy.
3. IT chemotherapy alone.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with adult acute lymphoblastic leukemia in remission. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References

1. Gaynor J, Chapman D, Little C, et al.: A cause-specific hazard rate analysis of prognostic factors among 199 adults with acute lymphoblastic leukemia: the Memorial Hospital experience since 1969. J Clin Oncol 6 (6): 1014-30, 1988.  [PUBMED Abstract]
   
   
2. Hoelzer D, Thiel E, Löffler H, et al.: Prognostic factors in a multicenter study for treatment of acute lymphoblastic leukemia in adults. Blood 71 (1): 123-31, 1988.  [PUBMED Abstract]
   
   
3. Linker CA, Levitt LJ, O'Donnell M, et al.: Treatment of adult acute lymphoblastic leukemia with intensive cyclical chemotherapy: a follow-up report. Blood 78 (11): 2814-22, 1991.  [PUBMED Abstract]
   
   
4. Zhang MJ, Hoelzer D, Horowitz MM, et al.: Long-term follow-up of adults with acute lymphoblastic leukemia in first remission treated with chemotherapy or bone marrow transplantation. The Acute Lymphoblastic Leukemia Working Committee. Ann Intern Med 123 (6): 428-31, 1995.  [PUBMED Abstract]
   
   
5. Larson RA, Dodge RK, Burns CP, et al.: A five-drug remission induction regimen with intensive consolidation for adults with acute lymphoblastic leukemia: cancer and leukemia group B study 8811. Blood 85 (8): 2025-37, 1995.  [PUBMED Abstract]
   
   
6. Cuttner J, Mick R, Budman DR, et al.: Phase III trial of brief intensive treatment of adult acute lymphocytic leukemia comparing daunorubicin and mitoxantrone: a CALGB Study. Leukemia 5 (5): 425-31, 1991.  [PUBMED Abstract]
   
   
7. Dekker AW, van't Veer MB, Sizoo W, et al.: Intensive postremission chemotherapy without maintenance therapy in adults with acute lymphoblastic leukemia. Dutch Hemato-Oncology Research Group. J Clin Oncol 15 (2): 476-82, 1997.  [PUBMED Abstract]
   
   
8. Thomas DA, Faderl S, Cortes J, et al.: Treatment of Philadelphia chromosome-positive acute lymphocytic leukemia with hyper-CVAD and imatinib mesylate. Blood 103 (12): 4396-407, 2004.  [PUBMED Abstract]
   
   
9. Yanada M, Takeuchi J, Sugiura I, et al.: High complete remission rate and promising outcome by combination of imatinib and chemotherapy for newly diagnosed BCR-ABL-positive acute lymphoblastic leukemia: a phase II study by the Japan Adult Leukemia Study Group. J Clin Oncol 24 (3): 460-6, 2006.  [PUBMED Abstract]
   
   
10. Wassmann B, Pfeifer H, Goekbuget N, et al.: Alternating versus concurrent schedules of imatinib and chemotherapy as front-line therapy for Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). Blood 108 (5): 1469-77, 2006.  [PUBMED Abstract]
    
    
11. Finiewicz KJ, Larson RA: Dose-intensive therapy for adult acute lymphoblastic leukemia. Semin Oncol 26 (1): 6-20, 1999.  [PUBMED Abstract]
    
    
12. Horowitz MM, Messerer D, Hoelzer D, et al.: Chemotherapy compared with bone marrow transplantation for adults with acute lymphoblastic leukemia in first remission. Ann Intern Med 115 (1): 13-8, 1991.  [PUBMED Abstract]
    
    
13. Sebban C, Lepage E, Vernant JP, et al.: Allogeneic bone marrow transplantation in adult acute lymphoblastic leukemia in first complete remission: a comparative study. French Group of Therapy of Adult Acute Lymphoblastic Leukemia. J Clin Oncol 12 (12): 2580-7, 1994.  [PUBMED Abstract]
    
    
14. Forman SJ, O'Donnell MR, Nademanee AP, et al.: Bone marrow transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia. Blood 70 (2): 587-8, 1987.  [PUBMED Abstract]
    
    
15. Fière D, Lepage E, Sebban C, et al.: Adult acute lymphoblastic leukemia: a multicentric randomized trial testing bone marrow transplantation as postremission therapy. The French Group on Therapy for Adult Acute Lymphoblastic Leukemia. J Clin Oncol 11 (10): 1990-2001, 1993.  [PUBMED Abstract]
    
    
16. Goldstone AH, Richards SM, Lazarus HM, et al.: In adults with standard-risk acute lymphoblastic leukemia, the greatest benefit is achieved from a matched sibling allogeneic transplantation in first complete remission, and an autologous transplantation is less effective than conventional consolidation/maintenance chemotherapy in all patients: final results of the International ALL Trial (MRC UKALL XII/ECOG E2993). Blood 111 (4): 1827-33, 2008.  [PUBMED Abstract]
    
    
17. Corvò R, Paoli G, Barra S, et al.: Total body irradiation correlates with chronic graft versus host disease and affects prognosis of patients with acute lymphoblastic leukemia receiving an HLA identical allogeneic bone marrow transplant. Int J Radiat Oncol Biol Phys 43 (3): 497-503, 1999.  [PUBMED Abstract]
    
    
18. Hoelzer D, Ludwig WD, Thiel E, et al.: Improved outcome in adult B-cell acute lymphoblastic leukemia. Blood 87 (2): 495-508, 1996.  [PUBMED Abstract]
    
    
19. Kantarjian HM, Walters RS, Smith TL, et al.: Identification of risk groups for development of central nervous system leukemia in adults with acute lymphocytic leukemia. Blood 72 (5): 1784-9, 1988.  [PUBMED Abstract]
    
    

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