Questions About Cancer? 1-800-4-CANCER

Chronic Lymphocytic Leukemia Treatment (PDQ®)

Health Professional Version
Last Modified: 04/16/2014

Stage I, II, III, and IV Chronic Lymphocytic Leukemia

Current Clinical Trials

Several decades of large, randomized, prospective trials of previously untreated patients have demonstrated statistically significant improvements in response rates, event-free survival (EFS), and progression-free survival (PFS) with comparison of combinations of drugs versus single-agent alkylators,[1,2] but only two trials have shown statistically significant improvement in overall survival (OS).[3,4]

The first trial, a comparison of chlorambucil versus fludarabine, after 15 years of median follow-up, showed improved median OS for patients on the fludarabine regimen at 63 months versus 59 months (P = .04), and an improved percentage of patients were alive at 8 years (31% vs. 19%, P = .04).[3,5][Level of evidence: 1iiA]

The second trial, which had 817 patients, compared FCR (fludarabine + cyclophosphamide + rituximab) versus FC (fludarabine + cyclophosphamide) with a median follow-up of 38 months and showed improved OS at 3 years for the rituximab combination (i.e., 87% vs. 83%, P = .01.[4][Level of evidence: 1iiA] Yet neither fludarabine nor FCR has been compared in a randomized study against watchful waiting in asymptomatic or minimally affected patients.

The improvements in response rates from more intensive regimens have maximized the clearance of minimal residual disease (MRD). In one prospective trial of 493 patients, clearance of MRD was an independent predictor of OS by multivariate analysis.[6] The surrogate endpoint of such clearance of residual disease, while prognostic,[6] has not been shown to improve survival in a randomized prospective trial; the necessary study would take patients who fail to completely clear the marrow with induction therapy and randomly assign them to further alternative treatment versus the same treatment later at relapse, looking at OS as the primary endpoint.[1,2]

The sequencing of the following treatment options cannot be determined from the current set of completed clinical trials. When patients become symptomatic or require treatment, FCR has become the most frequently chosen option outside of a clinical trial, mostly on the basis of the previously described prospective study.[4]

Treatment options:

Note: Standard options are roughly ordered by level of toxic effects, starting with the least toxic options. More recently discovered options are mentioned at the end of the list.

  1. Observation in asymptomatic or minimally affected patients.[7] Outside of the context of a clinical trial, treatment for asymptomatic or minimally affected patients with chronic lymphocytic leukemia (CLL) is observation. No data exist as yet to suggest any harm with a delay in therapy until the patient becomes symptomatic or develops serious cytopenias despite growth factor support. Because the rate of progression may vary from patient to patient, with long periods of stability and sometimes spontaneous regressions, frequent and careful observation is required to monitor the clinical course.

  2. Rituximab, a murine anti-CD20 monoclonal antibody.[8-12] When used alone, higher doses of rituximab or increased frequency or duration of therapy is required for comparable responses to those seen for other indolent lymphomas.

  3. Ofatumomab is a human anti-CD20 monoclonal antibody.[13] A trial of 138 patients, who were previously treated with fludarabine and alemtuzumab, showed overall response rates around 50% in patients refractory to fludarabine and with prior exposure to rituximab.[13,14][Level of evidence: 3iiiDiv]

  4. Oral alkylating agents with or without corticosteroids.[15] The French Cooperative Group on CLL randomly assigned 1,535 patients with previously untreated stage A disease to receive either chlorambucil or no immediate treatment and found no survival advantage for chlorambucil.[16][Level of evidence: 1iiA] A meta-analysis of six trials of immediate versus deferred therapy with chlorambucil (including the aforementioned trial by the French Cooperative Group) showed no difference in OS at 10 years.[7][Level of evidence: 1iiA]

  5. Fludarabine, 2-chlorodeoxyadenosine, or pentostatin as seen in the CLB-9011 trial, for example.[17-22]

    Several randomized trials have compared the purine analogs with chlorambucil; with cyclophosphamide, doxorubicin, and prednisone; or with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in previously untreated patients.[5,23-26] All of these trials showed higher or equivalent response rates for the purine analog and most showed an improvement in PFS, with one reaching significance in OS favoring fludarabine.[3,23-27][Level of evidence: 1iiDiii]

    A comparison of chlorambucil versus fludarabine, after 15 years' median follow-up, showed patients with improved median OS with fludarabine at 63 versus 59 months (P = .04) and an improved percentage of patients alive at 8 years (31% vs. 19%, P = .04).[3][Level of evidence: 1iiA] All of the trials demonstrated higher toxic effects with the purine analogs, especially granulocytopenic infections, herpes infections, autoimmune hemolytic anemia, and persistent thrombocytopenia.[28] The increased risk of infection may persist for months or years after treatment with a purine analog.[27,29]

    Although empiric evidence is lacking, some investigators recommend prophylaxis with trimethoprim-sulfa during therapy and for 6 to 12 months afterwards to prevent pneumocystis infection. In a similar way, other investigators employ prophylaxis (e.g., acyclovir) for the herpes viruses.[29] Purine analogs cause less hair loss or nausea than combination chemotherapy, including alkylators and anthracyclines.[25]

  6. Bendamustine.

    Bendamustine is a cytotoxic agent with bifunctional properties of an alkylator and a purine analog.[30] In previously treated and untreated patients, bendamustine with rituximab has shown response rates around 70% to 90%.[31,32][Level of evidence: 3iiiDiii]

    In a randomized comparison with chlorambucil in 319 previously treated patients, bendamustine showed a better response rate (68% vs. 31%, P < .0001) and PFS (21.6 months vs. 8 months) with a median follow-up of 35 months.[33][Level of evidence: 1iiDiii] The German CLL Study Group is comparing bendamustine plus rituximab versus FCR as first-line therapy in patients with CLL who require therapy.[31]

  7. Lenalidomide.

    Lenalidomide is an oral immunomodulatory agent with response rates over 50%, with or without rituximab, for patients with previously treated and untreated disease.[34-39][Level of evidence: 3iiiDiv] Prolonged, lower-dose approaches and attention to prevention of tumor lysis syndrome are recommended with this agent.[34,40] Combination therapy and long-term toxicities from using lenalidomide (such as increased myelodysplasia, as seen in myeloma patients) remain undefined for patients with CLL.

  8. Combination chemotherapy.

    A trial of 817 patients comparing FCR versus FC with a median follow-up of 38 months showed improved OS at 3 years for the rituximab combination (87% vs. 83%, P = .01).[4][Level of evidence: 1iiA] FCR has never been compared with watchful waiting up front in asymptomatic or minimally affected patients. The improvements in response rates from more intensive regimens have maximized the clearance of MRD. However, the surrogate endpoint of MRD clearance has not been proven to be a valid surrogate for improved survival in a randomized prospective trial; the necessary study would take patients who fail to completely clear the marrow with induction therapy and randomly assign them to further alternative treatment versus the same treatment later at relapse looking at OS as the primary endpoint.[1,2] A cumulative incidence of 6% to 8 % for myelodysplasia is seen at 5 to 7 years in patients who received fludarabine plus cyclophosphamide, with or without rituximab.[41,42]

    Other combination chemotherapy regimens include the following:

    • Fludarabine plus cyclophosphamide plus rituximab.[4,43-46]
    • Fludarabine plus rituximab as seen in the CLB-9712 and CLB-9011 trials.[47]
    • Fludarabine plus cyclophosphamide versus fludarabine plus cyclophosphamide plus rituximab.[4,48]
    • Pentostatin plus cyclophosphamide plus rituximab as seen in the MAYO-MC0183 trial, for example.[49,50]
    • Ofatumumab plus fludarabine plus cyclophosphamide.[51]
    • CVP: cyclophosphamide plus vincristine plus prednisone.[52]
    • CHOP: cyclophosphamide plus doxorubicin plus vincristine plus prednisone.[53]
    • Fludarabine plus cyclophosphamide versus fludarabine as seen in the E2997 trial [NCT00003764] and the LRF-CLL4 trial, for example.[54,55]
    • Fludarabine plus chlorambucil as seen in the CLB-9011 trial, for example.[56]

    A meta-analysis of ten trials comparing combination chemotherapy (before the availability of rituximab) with chlorambucil alone showed no difference in OS at 5 years.[7][Level of evidence: 1iiA]

  9. Involved-field radiation therapy. Relatively low doses of radiation therapy will affect an excellent response for months or years. Sometimes radiation therapy to one nodal area or the spleen will result in abscopal effect (i.e., the shrinkage of lymph node tumors in untreated sites).

  10. Alemtuzumab, the monoclonal antibody directed at CD52, shows activity in the setting of chemotherapy-resistant disease or high-risk untreated patients with 17p deletion or p53 mutation.[57-59] As a single agent, the subcutaneous route of delivery for alemtuzumab is preferred to the intravenous route in patients because of the similar efficacy and decreased adverse effects, including less acute allergic reactions that were shown in some nonrandomized reports.[59-63]

    In a combination regimen, subcutaneous alemtuzumab plus fludarabine (with or without cyclophosphamide) or intravenous alemtuzumab plus alkylating agents have resulted in excess infectious toxicities and death, with no compensatory improvement in efficacy in phase II trials.[64-66][Level of evidence: 3iiiDiv]

    Previously-treated patients

    In a randomized prospective study, 335 previously treated patients received intravenous alemtuzumab plus fludarabine versus fludarabine alone; with a median follow-up of 30 months, the combination of fludarabine plus intravenous alemtuzumab had better PFS, with a median of 23.7 months versus 16.5 months (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.47–0.80; P = .0003); and better OS, with a median not reached, versus 52.9 months (HR, 0.65; 95% CI, 0.45–0.94; P = .021).[67][Level of evidence: 1iiA] Profound and long-lasting immunosuppression has been seen, which mandates monitoring for reactivation of cytomegalovirus and prophylaxis for pneumocystis and herpes virus infections.[68,69] Antibiotic prophylaxis includes trimethoprim and sulfamethoxazole, itraconazole, and acyclovir (or ganciclovir) for asymptomatic cytomegalovirus viremia.

  11. Bone marrow and peripheral stem cell transplantations are under clinical evaluation.[70-76]

    In a prospective randomized trial, 241 previously untreated patients younger than 66 years with advanced-stage disease received induction therapy with a CHOP-based regimen followed by fludarabine.[77] Complete responders (105 patients) were randomly assigned to undergo autologous stem cell transplantation (ASCT) or observation, while the other 136 patients were randomly assigned to receive dexamethasone, high-dose aracytin, and cisplatin reinduction followed by either ASCT or fludarabine plus cyclophosphamide. Although the 3-year EFS favored ASCT in complete responders, there was no difference in OS in any of the randomized comparisons.[77][Level of evidence: 1iiDi]

    Patients with adverse prognostic factors are very likely to die from CLL. These patients are candidates for clinical trials that employ high-dose chemotherapy and immunotherapy with myeloablative or nonmyeloablative allogeneic peripheral stem cell transplantation.[70-75,78-85] Although most patients who attain complete remission after ASCT eventually relapse,[76] a survival plateau for allogeneic stem cell support suggests an additional graft-versus-leukemia effect.[85]

  12. Ibrutinib is a selective irreversible inhibitor of Bruton tyrosine kinase, a signaling molecule located upstream in the B-cell receptor signaling cascade. Other trials of relapsed and refractory CLL have shown durable responses to the oral agent in phase I and II studies.[86][Level of evidence: 3iiiDiii] A phase Ib–II trial (NCT01105247) of 85 patients with relapsed or refractory CLL showed a 26-month PFS rate of 76%, including patients with 17p- or unmutated IgVH fluorescence in situ hybridization testing.[87][Level of evidence: 3iiiDiii]

  13. Autologous T-cells were modified by a lentiviral vector to incorporate antigen receptor specificity for the B-cell antigen CD19 and then infused into a previously treated patient.[88] A dramatic response lasting 6 months has prompted larger trials of this concept.[88][Level of evidence: 3iiiDiv] Ongoing clinical trials are testing this concept.

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage I chronic lymphocytic leukemia, stage II chronic lymphocytic leukemia, stage III chronic lymphocytic leukemia and stage IV chronic lymphocytic leukemia. 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. Developments in the treatment of lymphoproliferative disorders: rising to the new challenges of CLL therapy. A report of a symposium presented during the 48th American Society of Hematology Annual Meeting and Exposition, December 8, 2006, Orlando, Florida. Clin Adv Hematol Oncol 5 (3 Suppl 5): 1-14; quiz 15-6, 2007.  [PUBMED Abstract]

  2. Montserrat E, Moreno C, Esteve J, et al.: How I treat refractory CLL. Blood 107 (4): 1276-83, 2006.  [PUBMED Abstract]

  3. Rai KR, Peterson, Frederick R. Appelbaum BL, Appelbaum FR, et al.: Long-term survival analysis of the North American Intergroup Study C9011 comparing fludarabine (F) and chlorambucil (C) in previously untreated patients with chronic lymphocytic leukemia (CLL). [Abstract] Blood 114 (22): A-536, 2009. 

  4. Hallek M, Fischer K, Fingerle-Rowson G, et al.: Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial. Lancet 376 (9747): 1164-74, 2010.  [PUBMED Abstract]

  5. Rai KR, Peterson BL, Appelbaum FR, et al.: Fludarabine compared with chlorambucil as primary therapy for chronic lymphocytic leukemia. N Engl J Med 343 (24): 1750-7, 2000.  [PUBMED Abstract]

  6. Böttcher S, Ritgen M, Fischer K, et al.: Minimal residual disease quantification is an independent predictor of progression-free and overall survival in chronic lymphocytic leukemia: a multivariate analysis from the randomized GCLLSG CLL8 trial. J Clin Oncol 30 (9): 980-8, 2012.  [PUBMED Abstract]

  7. Chemotherapeutic options in chronic lymphocytic leukemia: a meta-analysis of the randomized trials. CLL Trialists' Collaborative Group. J Natl Cancer Inst 91 (10): 861-8, 1999.  [PUBMED Abstract]

  8. Mavromatis B, Cheson BD: Monoclonal antibody therapy of chronic lymphocytic leukemia. J Clin Oncol 21 (9): 1874-81, 2003.  [PUBMED Abstract]

  9. O'Brien SM, Kantarjian H, Thomas DA, et al.: Rituximab dose-escalation trial in chronic lymphocytic leukemia. J Clin Oncol 19 (8): 2165-70, 2001.  [PUBMED Abstract]

  10. Byrd JC, Murphy T, Howard RS, et al.: Rituximab using a thrice weekly dosing schedule in B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity. J Clin Oncol 19 (8): 2153-64, 2001.  [PUBMED Abstract]

  11. Hainsworth JD, Litchy S, Barton JH, et al.: Single-agent rituximab as first-line and maintenance treatment for patients with chronic lymphocytic leukemia or small lymphocytic lymphoma: a phase II trial of the Minnie Pearl Cancer Research Network. J Clin Oncol 21 (9): 1746-51, 2003.  [PUBMED Abstract]

  12. Castro JE, Sandoval-Sus JD, Bole J, et al.: Rituximab in combination with high-dose methylprednisolone for the treatment of fludarabine refractory high-risk chronic lymphocytic leukemia. Leukemia 22 (11): 2048-53, 2008.  [PUBMED Abstract]

  13. Wierda WG, Kipps TJ, Mayer J, et al.: Ofatumumab as single-agent CD20 immunotherapy in fludarabine-refractory chronic lymphocytic leukemia. J Clin Oncol 28 (10): 1749-55, 2010.  [PUBMED Abstract]

  14. Wierda WG, Padmanabhan S, Chan GW, et al.: Ofatumumab is active in patients with fludarabine-refractory CLL irrespective of prior rituximab: results from the phase 2 international study. Blood 118 (19): 5126-9, 2011.  [PUBMED Abstract]

  15. A randomized clinical trial of chlorambucil versus COP in stage B chronic lymphocytic leukemia. The French Cooperative Group on Chronic Lymphocytic Leukemia. Blood 75 (7): 1422-5, 1990.  [PUBMED Abstract]

  16. Dighiero G, Maloum K, Desablens B, et al.: Chlorambucil in indolent chronic lymphocytic leukemia. French Cooperative Group on Chronic Lymphocytic Leukemia. N Engl J Med 338 (21): 1506-14, 1998.  [PUBMED Abstract]

  17. O'Brien S, Kantarjian H, Beran M, et al.: Results of fludarabine and prednisone therapy in 264 patients with chronic lymphocytic leukemia with multivariate analysis-derived prognostic model for response to treatment. Blood 82 (6): 1695-700, 1993.  [PUBMED Abstract]

  18. Tallman MS, Hakimian D, Zanzig C, et al.: Cladribine in the treatment of relapsed or refractory chronic lymphocytic leukemia. J Clin Oncol 13 (4): 983-8, 1995.  [PUBMED Abstract]

  19. Saven A, Lemon RH, Kosty M, et al.: 2-Chlorodeoxyadenosine activity in patients with untreated chronic lymphocytic leukemia. J Clin Oncol 13 (3): 570-4, 1995.  [PUBMED Abstract]

  20. Dillman RO, Mick R, McIntyre OR: Pentostatin in chronic lymphocytic leukemia: a phase II trial of Cancer and Leukemia group B. J Clin Oncol 7 (4): 433-8, 1989.  [PUBMED Abstract]

  21. Morrison VA, Rai KR, Peterson BL, et al.: Impact of therapy with chlorambucil, fludarabine, or fludarabine plus chlorambucil on infections in patients with chronic lymphocytic leukemia: Intergroup Study Cancer and Leukemia Group B 9011. J Clin Oncol 19 (16): 3611-21, 2001.  [PUBMED Abstract]

  22. Robak T, Blonski JZ, Gora-Tybor J, et al.: Cladribine alone and in combination with cyclophosphamide or cyclophosphamide plus mitoxantrone in the treatment of progressive chronic lymphocytic leukemia: report of a prospective, multicenter, randomized trial of the Polish Adult Leukemia Group (PALG CLL2). Blood 108 (2): 473-9, 2006.  [PUBMED Abstract]

  23. Robak T, Bloński JZ, Kasznicki M, et al.: Cladribine with prednisone versus chlorambucil with prednisone as first-line therapy in chronic lymphocytic leukemia: report of a prospective, randomized, multicenter trial. Blood 96 (8): 2723-9, 2000.  [PUBMED Abstract]

  24. Johnson S, Smith AG, Löffler H, et al.: Multicentre prospective randomised trial of fludarabine versus cyclophosphamide, doxorubicin, and prednisone (CAP) for treatment of advanced-stage chronic lymphocytic leukaemia. The French Cooperative Group on CLL. Lancet 347 (9013): 1432-8, 1996.  [PUBMED Abstract]

  25. Leporrier M, Chevret S, Cazin B, et al.: Randomized comparison of fludarabine, CAP, and ChOP in 938 previously untreated stage B and C chronic lymphocytic leukemia patients. Blood 98 (8): 2319-25, 2001.  [PUBMED Abstract]

  26. Eichhorst BF, Busch R, Stilgenbauer S, et al.: First-line therapy with fludarabine compared with chlorambucil does not result in a major benefit for elderly patients with advanced chronic lymphocytic leukemia. Blood 114 (16): 3382-91, 2009.  [PUBMED Abstract]

  27. Steurer M, Pall G, Richards S, et al.: Purine antagonists for chronic lymphocytic leukaemia. Cochrane Database Syst Rev 3: CD004270, 2006.  [PUBMED Abstract]

  28. Dearden C, Wade R, Else M, et al.: The prognostic significance of a positive direct antiglobulin test in chronic lymphocytic leukemia: a beneficial effect of the combination of fludarabine and cyclophosphamide on the incidence of hemolytic anemia. Blood 111 (4): 1820-6, 2008.  [PUBMED Abstract]

  29. Perkins JG, Flynn JM, Howard RS, et al.: Frequency and type of serious infections in fludarabine-refractory B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma: implications for clinical trials in this patient population. Cancer 94 (7): 2033-9, 2002.  [PUBMED Abstract]

  30. Leoni LM, Bailey B, Reifert J, et al.: Bendamustine (Treanda) displays a distinct pattern of cytotoxicity and unique mechanistic features compared with other alkylating agents. Clin Cancer Res 14 (1): 309-17, 2008.  [PUBMED Abstract]

  31. Fischer K, Cramer P, Busch R, et al.: Bendamustine combined with rituximab in patients with relapsed and/or refractory chronic lymphocytic leukemia: a multicenter phase II trial of the German Chronic Lymphocytic Leukemia Study Group. J Clin Oncol 29 (26): 3559-66, 2011.  [PUBMED Abstract]

  32. Iannitto E, Morabito F, Mancuso S, et al.: Bendamustine with or without rituximab in the treatment of relapsed chronic lymphocytic leukaemia: an Italian retrospective study. Br J Haematol 153 (3): 351-7, 2011.  [PUBMED Abstract]

  33. Knauf WU, Lissichkov T, Aldaoud A, et al.: Phase III randomized study of bendamustine compared with chlorambucil in previously untreated patients with chronic lymphocytic leukemia. J Clin Oncol 27 (26): 4378-84, 2009.  [PUBMED Abstract]

  34. Chen CI, Bergsagel PL, Paul H, et al.: Single-agent lenalidomide in the treatment of previously untreated chronic lymphocytic leukemia. J Clin Oncol 29 (9): 1175-81, 2011.  [PUBMED Abstract]

  35. Chanan-Khan A, Miller KC, Musial L, et al.: Clinical efficacy of lenalidomide in patients with relapsed or refractory chronic lymphocytic leukemia: results of a phase II study. J Clin Oncol 24 (34): 5343-9, 2006.  [PUBMED Abstract]

  36. Ferrajoli A, Lee BN, Schlette EJ, et al.: Lenalidomide induces complete and partial remissions in patients with relapsed and refractory chronic lymphocytic leukemia. Blood 111 (11): 5291-7, 2008.  [PUBMED Abstract]

  37. Badoux XC, Keating MJ, Wen S, et al.: Lenalidomide as initial therapy of elderly patients with chronic lymphocytic leukemia. Blood 118 (13): 3489-98, 2011.  [PUBMED Abstract]

  38. Wendtner CM, Hillmen P, Mahadevan D, et al.: Final results of a multicenter phase 1 study of lenalidomide in patients with relapsed or refractory chronic lymphocytic leukemia. Leuk Lymphoma 53 (3): 417-23, 2012.  [PUBMED Abstract]

  39. Badoux XC, Keating MJ, Wen S, et al.: Phase II study of lenalidomide and rituximab as salvage therapy for patients with relapsed or refractory chronic lymphocytic leukemia. J Clin Oncol 31 (5): 584-91, 2013.  [PUBMED Abstract]

  40. Moutouh-de Parseval LA, Weiss L, DeLap RJ, et al.: Tumor lysis syndrome/tumor flare reaction in lenalidomide-treated chronic lymphocytic leukemia. J Clin Oncol 25 (31): 5047, 2007.  [PUBMED Abstract]

  41. Smith MR, Neuberg D, Flinn IW, et al.: Incidence of therapy-related myeloid neoplasia after initial therapy for chronic lymphocytic leukemia with fludarabine-cyclophosphamide versus fludarabine: long-term follow-up of US Intergroup Study E2997. Blood 118 (13): 3525-7, 2011.  [PUBMED Abstract]

  42. Carney DA, Westerman DA, Tam CS, et al.: Therapy-related myelodysplastic syndrome and acute myeloid leukemia following fludarabine combination chemotherapy. Leukemia 24 (12): 2056-62, 2010.  [PUBMED Abstract]

  43. Lamanna N, Jurcic JG, Noy A, et al.: Sequential therapy with fludarabine, high-dose cyclophosphamide, and rituximab in previously untreated patients with chronic lymphocytic leukemia produces high-quality responses: molecular remissions predict for durable complete responses. J Clin Oncol 27 (4): 491-7, 2009.  [PUBMED Abstract]

  44. Foon KA, Boyiadzis M, Land SR, et al.: Chemoimmunotherapy with low-dose fludarabine and cyclophosphamide and high dose rituximab in previously untreated patients with chronic lymphocytic leukemia. J Clin Oncol 27 (4): 498-503, 2009.  [PUBMED Abstract]

  45. Tam CS, O'Brien S, Wierda W, et al.: Long-term results of the fludarabine, cyclophosphamide, and rituximab regimen as initial therapy of chronic lymphocytic leukemia. Blood 112 (4): 975-80, 2008.  [PUBMED Abstract]

  46. Badoux XC, Keating MJ, Wang X, et al.: Fludarabine, cyclophosphamide, and rituximab chemoimmunotherapy is highly effective treatment for relapsed patients with CLL. Blood 117 (11): 3016-24, 2011.  [PUBMED Abstract]

  47. Woyach JA, Ruppert AS, Heerema NA, et al.: Chemoimmunotherapy with fludarabine and rituximab produces extended overall survival and progression-free survival in chronic lymphocytic leukemia: long-term follow-up of CALGB study 9712. J Clin Oncol 29 (10): 1349-55, 2011.  [PUBMED Abstract]

  48. Robak T, Dmoszynska A, Solal-Céligny P, et al.: Rituximab plus fludarabine and cyclophosphamide prolongs progression-free survival compared with fludarabine and cyclophosphamide alone in previously treated chronic lymphocytic leukemia. J Clin Oncol 28 (10): 1756-65, 2010.  [PUBMED Abstract]

  49. Kay NE, Geyer SM, Call TG, et al.: Combination chemoimmunotherapy with pentostatin, cyclophosphamide, and rituximab shows significant clinical activity with low accompanying toxicity in previously untreated B chronic lymphocytic leukemia. Blood 109 (2): 405-11, 2007.  [PUBMED Abstract]

  50. Shanafelt TD, Lin T, Geyer SM, et al.: Pentostatin, cyclophosphamide, and rituximab regimen in older patients with chronic lymphocytic leukemia. Cancer 109 (11): 2291-8, 2007.  [PUBMED Abstract]

  51. Wierda WG, Kipps TJ, Dürig J, et al.: Chemoimmunotherapy with O-FC in previously untreated patients with chronic lymphocytic leukemia. Blood 117 (24): 6450-8, 2011.  [PUBMED Abstract]

  52. Raphael B, Andersen JW, Silber R, et al.: Comparison of chlorambucil and prednisone versus cyclophosphamide, vincristine, and prednisone as initial treatment for chronic lymphocytic leukemia: long-term follow-up of an Eastern Cooperative Oncology Group randomized clinical trial. J Clin Oncol 9 (5): 770-6, 1991.  [PUBMED Abstract]

  53. Is the CHOP regimen a good treatment for advanced CLL? Results from two randomized clinical trials. French Cooperative Group on Chronic Lymphocytic Leukemia. Leuk Lymphoma 13 (5-6): 449-56, 1994.  [PUBMED Abstract]

  54. Flinn IW, Neuberg DS, Grever MR, et al.: Phase III trial of fludarabine plus cyclophosphamide compared with fludarabine for patients with previously untreated chronic lymphocytic leukemia: US Intergroup Trial E2997. J Clin Oncol 25 (7): 793-8, 2007.  [PUBMED Abstract]

  55. Catovsky D, Richards S, Matutes E, et al.: Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial. Lancet 370 (9583): 230-9, 2007.  [PUBMED Abstract]

  56. Morrison VA, Rai KR, Peterson BL, et al.: Therapy-related myeloid leukemias are observed in patients with chronic lymphocytic leukemia after treatment with fludarabine and chlorambucil: results of an intergroup study, cancer and leukemia group B 9011. J Clin Oncol 20 (18): 3878-84, 2002.  [PUBMED Abstract]

  57. Moreton P, Kennedy B, Lucas G, et al.: Eradication of minimal residual disease in B-cell chronic lymphocytic leukemia after alemtuzumab therapy is associated with prolonged survival. J Clin Oncol 23 (13): 2971-9, 2005.  [PUBMED Abstract]

  58. Parikh SA, Keating MJ, O'Brien S, et al.: Frontline chemoimmunotherapy with fludarabine, cyclophosphamide, alemtuzumab, and rituximab for high-risk chronic lymphocytic leukemia. Blood 118 (8): 2062-8, 2011.  [PUBMED Abstract]

  59. Pettitt AR, Jackson R, Carruthers S, et al.: Alemtuzumab in combination with methylprednisolone is a highly effective induction regimen for patients with chronic lymphocytic leukemia and deletion of TP53: final results of the national cancer research institute CLL206 trial. J Clin Oncol 30 (14): 1647-55, 2012.  [PUBMED Abstract]

  60. Stilgenbauer S, Zenz T, Winkler D, et al.: Subcutaneous alemtuzumab in fludarabine-refractory chronic lymphocytic leukemia: clinical results and prognostic marker analyses from the CLL2H study of the German Chronic Lymphocytic Leukemia Study Group. J Clin Oncol 27 (24): 3994-4001, 2009.  [PUBMED Abstract]

  61. Cortelezzi A, Pasquini MC, Gardellini A, et al.: Low-dose subcutaneous alemtuzumab in refractory chronic lymphocytic leukaemia (CLL): results of a prospective, single-arm multicentre study. Leukemia 23 (11): 2027-33, 2009.  [PUBMED Abstract]

  62. Osterborg A, Foà R, Bezares RF, et al.: Management guidelines for the use of alemtuzumab in chronic lymphocytic leukemia. Leukemia 23 (11): 1980-8, 2009.  [PUBMED Abstract]

  63. Gritti G, Reda G, Maura F, et al.: Low dose alemtuzumab in patients with fludarabine-refractory chronic lymphocytic leukemia. Leuk Lymphoma 53 (3): 424-9, 2012.  [PUBMED Abstract]

  64. Lin TS, Donohue KA, Byrd JC, et al.: Consolidation therapy with subcutaneous alemtuzumab after fludarabine and rituximab induction therapy for previously untreated chronic lymphocytic leukemia: final analysis of CALGB 10101. J Clin Oncol 28 (29): 4500-6, 2010.  [PUBMED Abstract]

  65. Badoux XC, Keating MJ, Wang X, et al.: Cyclophosphamide, fludarabine, alemtuzumab, and rituximab as salvage therapy for heavily pretreated patients with chronic lymphocytic leukemia. Blood 118 (8): 2085-93, 2011.  [PUBMED Abstract]

  66. Lepretre S, Aurran T, Mahé B, et al.: Excess mortality after treatment with fludarabine and cyclophosphamide in combination with alemtuzumab in previously untreated patients with chronic lymphocytic leukemia in a randomized phase 3 trial. Blood 119 (22): 5104-10, 2012.  [PUBMED Abstract]

  67. Elter T, Gercheva-Kyuchukova L, Pylylpenko H, et al.: Fludarabine plus alemtuzumab versus fludarabine alone in patients with previously treated chronic lymphocytic leukaemia: a randomised phase 3 trial. Lancet Oncol 12 (13): 1204-13, 2011.  [PUBMED Abstract]

  68. Elter T, Vehreschild JJ, Gribben J, et al.: Management of infections in patients with chronic lymphocytic leukemia treated with alemtuzumab. Ann Hematol 88 (2): 121-32, 2009.  [PUBMED Abstract]

  69. Byrd JC, Peterson BL, Rai KR, et al.: Fludarabine followed by alemtuzumab consolidation for previously untreated chronic lymphocytic leukemia: final report of Cancer and Leukemia Group B study 19901. Leuk Lymphoma 50 (10): 1589-96, 2009.  [PUBMED Abstract]

  70. Doney KC, Chauncey T, Appelbaum FR, et al.: Allogeneic related donor hematopoietic stem cell transplantation for treatment of chronic lymphocytic leukemia. Bone Marrow Transplant 29 (10): 817-23, 2002.  [PUBMED Abstract]

  71. Schetelig J, Thiede C, Bornhauser M, et al.: Evidence of a graft-versus-leukemia effect in chronic lymphocytic leukemia after reduced-intensity conditioning and allogeneic stem-cell transplantation: the Cooperative German Transplant Study Group. J Clin Oncol 21 (14): 2747-53, 2003.  [PUBMED Abstract]

  72. Ritgen M, Stilgenbauer S, von Neuhoff N, et al.: Graft-versus-leukemia activity may overcome therapeutic resistance of chronic lymphocytic leukemia with unmutated immunoglobulin variable heavy-chain gene status: implications of minimal residual disease measurement with quantitative PCR. Blood 104 (8): 2600-2, 2004.  [PUBMED Abstract]

  73. Moreno C, Villamor N, Colomer D, et al.: Allogeneic stem-cell transplantation may overcome the adverse prognosis of unmutated VH gene in patients with chronic lymphocytic leukemia. J Clin Oncol 23 (15): 3433-8, 2005.  [PUBMED Abstract]

  74. Khouri IF, Keating MJ, Saliba RM, et al.: Long-term follow-up of patients with CLL treated with allogeneic hematopoietic transplantation. Cytotherapy 4 (3): 217-21, 2002.  [PUBMED Abstract]

  75. Pavletic SZ, Khouri IF, Haagenson M, et al.: Unrelated donor marrow transplantation for B-cell chronic lymphocytic leukemia after using myeloablative conditioning: results from the Center for International Blood and Marrow Transplant research. J Clin Oncol 23 (24): 5788-94, 2005.  [PUBMED Abstract]

  76. Dreger P, Döhner H, McClanahan F, et al.: Early autologous stem cell transplantation for chronic lymphocytic leukemia: long-term follow-up of the German CLL Study Group CLL3 trial. Blood 119 (21): 4851-9, 2012.  [PUBMED Abstract]

  77. Sutton L, Chevret S, Tournilhac O, et al.: Autologous stem cell transplantation as a first-line treatment strategy for chronic lymphocytic leukemia: a multicenter, randomized, controlled trial from the SFGM-TC and GFLLC. Blood 117 (23): 6109-19, 2011.  [PUBMED Abstract]

  78. Sorror ML, Maris MB, Sandmaier BM, et al.: Hematopoietic cell transplantation after nonmyeloablative conditioning for advanced chronic lymphocytic leukemia. J Clin Oncol 23 (16): 3819-29, 2005.  [PUBMED Abstract]

  79. Toze CL, Dalal CB, Nevill TJ, et al.: Allogeneic haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: outcome in a 20-year cohort. Br J Haematol 158 (2): 174-85, 2012.  [PUBMED Abstract]

  80. Milligan DW, Fernandes S, Dasgupta R, et al.: Results of the MRC pilot study show autografting for younger patients with chronic lymphocytic leukemia is safe and achieves a high percentage of molecular responses. Blood 105 (1): 397-404, 2005.  [PUBMED Abstract]

  81. Khouri IF, Saliba RM, Admirand J, et al.: Graft-versus-leukaemia effect after non-myeloablative haematopoietic transplantation can overcome the unfavourable expression of ZAP-70 in refractory chronic lymphocytic leukaemia. Br J Haematol 137 (4): 355-63, 2007.  [PUBMED Abstract]

  82. Sorror ML, Storer BE, Sandmaier BM, et al.: Five-year follow-up of patients with advanced chronic lymphocytic leukemia treated with allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning. J Clin Oncol 26 (30): 4912-20, 2008.  [PUBMED Abstract]

  83. Schetelig J, van Biezen A, Brand R, et al.: Allogeneic hematopoietic stem-cell transplantation for chronic lymphocytic leukemia with 17p deletion: a retrospective European Group for Blood and Marrow Transplantation analysis. J Clin Oncol 26 (31): 5094-100, 2008.  [PUBMED Abstract]

  84. Malhotra P, Hogan WJ, Litzow MR, et al.: Long-term outcome of allogeneic stem cell transplantation in chronic lymphocytic leukemia: analysis after a minimum follow-up of 5 years. Leuk Lymphoma 49 (9): 1724-30, 2008.  [PUBMED Abstract]

  85. Dreger P, Döhner H, Ritgen M, et al.: Allogeneic stem cell transplantation provides durable disease control in poor-risk chronic lymphocytic leukemia: long-term clinical and MRD results of the German CLL Study Group CLL3X trial. Blood 116 (14): 2438-47, 2010.  [PUBMED Abstract]

  86. Advani RH, Buggy JJ, Sharman JP, et al.: Bruton tyrosine kinase inhibitor ibrutinib (PCI-32765) has significant activity in patients with relapsed/refractory B-cell malignancies. J Clin Oncol 31 (1): 88-94, 2013.  [PUBMED Abstract]

  87. Byrd JC, Furman RR, Coutre SE, et al.: Targeting BTK with ibrutinib in relapsed chronic lymphocytic leukemia. N Engl J Med 369 (1): 32-42, 2013.  [PUBMED Abstract]

  88. Porter DL, Levine BL, Kalos M, et al.: Chimeric antigen receptor-modified T cells in chronic lymphoid leukemia. N Engl J Med 365 (8): 725-33, 2011.  [PUBMED Abstract]