Leukemia-cell proliferation and disease progression in patients with early stage chronic lymphocytic leukemia.

The clinical course of patients with recently diagnosed early stage chronic lymphocytic leukemia (CLL) is highly variable. We examined the relationship between CLL-cell birth rate and treatment-free survival (TFS) in 97 patients with recently diagnosed, Rai stage 0-II CLL in a blinded, prospective study, using in vivo 2H2O labeling. Birth rates ranged from 0.07 to 1.31% new cells per day. With median follow-up of 4.0 years, 33 subjects (34%) required treatment by NCI criteria. High-birth rate was observed in 44% of subjects and was significantly associated with shorter TFS, unmutated IGHV status and expression of ZAP70 and of CD38. In multivariable modeling considering age, gender, Rai stage, expression of ZAP70 or CD38, IGHV mutation status and FISH cytogenetics, only CLL-cell birth rate and IGHV mutation status met criteria for inclusion. Hazard ratios were 3.51 (P=0.002) for high-birth rate and 4.93 (P<0.001) for unmutated IGHV. The association between elevated birth rate and shorter TFS was observed in subjects with either mutated or unmutated IGHVs, and the use of both markers was a better predictor of TFS than either parameter alone. Thus, an increased CLL birth rate in early stage disease is a strong predictor of disease progression and earlier treatment.

BTK inhibition results in impaired CXCR4 chemokine receptor surface expression, signaling and function in chronic lymphocytic leukemia.

Bruton's tyrosine kinase (BTK) is involved in the regulation of B-cell growth, migration and adhesion. The importance of BTK in cell trafficking is emphasized by the clonal contraction proceeded by lymphocytosis typical for the enzyme inhibitor, ibrutinib, in B-cell malignancies, including chronic lymphocytic leukemia (CLL). Here, we investigated BTK regulation of leukemic B-cell trafficking in a mouse model of aggressive TCL1 CLL-like disease. Inhibiting BTK by ibrutinib reduced surface membrane (sm) levels of CXCR4 but not CXCR5, CD49d and other adhesion/homing receptors. Decreased smCXCR4 levels resulted from blocking receptor signal transduction, which in turn aborted cycling from and to the membrane. This resulted in rapid re-distribution of CLL cells from spleens and lymph nodes into the circulation. CLL cells with impaired smCXCR4 from BTK inhibition failed to home to spleens. These functional changes mainly resulted from inhibition of CXCR4 phosphorylation at Ser339, mediated directly by blocking BTK enzymatic activity and indirectly by affecting the function of downstream targets PLCγ2 and PKCµ, and eventually synthesis of PIM-1 and BTK itself. Our data identify CXCR4 as a key regulator in BTK-mediated CLL-cell retention and have elucidated a complex set of not previously described mechanisms responsible for these effects.

Cytoplasmic myosin-exposed apoptotic cells appear with caspase-3 activation and enhance CLL cell viability.

The degree of chronic lymphocytic leukemia (CLL) B-cell antigen receptor (BCR) binding to myosin-exposed apoptotic cells (MEACs) correlates with worse patient outcomes, suggesting a link to disease activity. Therefore, we studied MEAC formation and the effects of MEAC binding on CLL cells. In cell line studies, both intrinsic (spontaneous or camptothecin-induced) and extrinsic (FasL- or anti-Fas-induced) apoptosis created a high percent of MEACs over time in a process associated with caspase-3 activation, leading to cytoplasmic myosin cleavage and trafficking to cell membranes. The involvement of common apoptosis pathways suggests that most cells can produce MEACs and indeed CLL cells themselves form MEACs. Consistent with the idea that MEAC formation may be a signal to remove dying cells, we found that natural IgM antibodies bind to MEACs. Functionally, co-culture of MEACs with CLL cells, regardless of immunoglobulin heavy-chain variable region gene mutation status, improved leukemic cell viability. Based on inhibitor studies, this improved viability involved BCR signaling molecules. These results support the hypothesis that stimulation of CLL cells with antigen, such as those on MEACs, promotes CLL cell viability, which in turn could lead to progression to worse disease.

Treatment of hairy-cell leukemia with cladribine: response, toxicity, and long-term follow-up.

PURPOSE: To analyze initial and long-term outcomes after treatment of patients with active hairy-cell leukemia (HCL) with a single cycle of cladribine (2-CdA). PATIENTS AND METHODS: Forty-nine patients with active HCL were treated with 2-CdA by continuous intravenous infusion at 0.1 mg/kg/d for a total of 7 days at the Long Island Jewish Medical Center between September 1990 and August 1992. Here we report on all patients followed-up until April 1996. RESULTS: At 3 months after treatment, complete response (CR) occurred in 37 patients (76%) and partial response (PR) occurred in 12 patients (24%), for an overall response rate of 100% (95% confidence interval, 94% to 100%). At a median follow-up of 55 months, the relapse-free survival is 80% and overall survival is 95%. Ten patients (20%) have relapsed. Of the 26 patients in whom lymphocyte phenotyping was performed, four were found to have a CD25-negative phenotype. All four of these patients had PRs only and all relapsed. Eight patients have been re-treated with 2-CdA, and all achieved at least a partial remission; two of these have already relapsed with remission durations of less than 1 year. Five second malignancies have occurred in four patients. CONCLUSION: With a median follow-up of more than 4 years, 39 patients (80%) continue in remission. Only two deaths have occurred. A CD25-negative phenotype may predict for a poorer response to 2-CdA. Patients who relapse may be re-treated with 2-CdA, but subsequent remissions may be of shorter duration. There has not been a markedly increased incidence of second malignancies or late opportunistic infections.

Alemtuzumab in previously treated chronic lymphocytic leukemia patients who also had received fludarabine.

PURPOSE: This phase II pilot study determined the efficacy and safety of alemtuzumab (Campath-1H; Burroughs Wellcome, United Kingdom) in patients with chronic lymphocytic leukemia (CLL), all of whom had previously received fludarabine and other chemotherapy regimens. PATIENTS AND METHODS: Twenty-four patients were treated with intravenous alemtuzumab at six centers in the United States. The target dose of 30 mg over 2 hours, three times weekly, was administered for up to 16 weeks. Responses were evaluated by an independent panel of experts using 1996 National Cancer Institute-sponsored Working Group criteria. Safety assessments included analysis of lymphocyte subpopulations. Antimicrobial prophylaxis was not mandatory. RESULTS: Eight patients (33%) achieved a major response (all partial remissions), with a median time to response of 3.9 months (range, 1.6 to 5.3 months). The median duration of response was 15.4 months (range, 4.6 to >or= 38.0 months), the median time to disease progression was 19.6 months (range, 7.7 to >or= 42.0 months), and the median survival time was 35.8 months (range, 8.8 to >or= 47.1 months). Acute infusion-related events, mainly grades 1 and 2, were most common and most severe in the first week. Ten patients (eight nonresponders and two responders) experienced major infections on-study. Pneumocystis carinii pneumonia was reported in two patients on-study; neither had received prophylaxis. Median CD4+ and CD8+ counts decreased and then began to increase by the end of the study, with further recovery by 1-month follow-up. One of 53 samples obtained from 10 patients had a low titer of alemtuzumab antibodies. CONCLUSION: Alemtuzumab has significant activity in poor-prognosis, fludarabine-treated CLL patients. However, because of a relatively high incidence of opportunistic infections accompanying profound lymphopenia, future protocols should include mandatory prophylaxis.

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.

PURPOSE: We sought to determine whether therapy with single-agent fludarabine compared with chlorambucil alone or the combination of both agents had an impact on the incidence and spectrum of infections among a series of previously untreated patients with B-cell chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Five hundred fifty-four previously untreated CLL patients with intermediate/high-risk Rai-stage disease were enrolled onto an intergroup protocol. Patients were randomized to therapy with chlorambucil, fludarabine, or fludarabine plus chlorambucil. Data pertaining to infection were available on 518 patients. Differences in infections among treatment arms were tested with the Kruskal-Wallis, Wilcoxon, and chi(2) tests. RESULTS: A total of 1,107 infections (241 major infections) occurred in 518 patients over the infection follow-up period (interval from study entry until either reinstitution of initial therapy, therapy with a second agent, or death). Patients treated with fludarabine plus chlorambucil had more infections than those receiving either single agent (P <.0001). Comparing the two single-agent arms, there were more infections on the fludarabine arm (P =.055) per month of follow-up. Fludarabine therapy was associated with more major infections and more herpesvirus infections compared with chlorambucil (P =.008 and P =.004, respectively). Rai stage and best response to therapy were not associated with infection. A low serum immunoglobulin G was associated with number of infections (P =.02). Age was associated with incidence of major infection in the combination arm (P =.004). CONCLUSION: Combination therapy with fludarabine plus chlorambucil resulted in significantly more infections than treatment with either single agent. Patients receiving single-agent fludarabine had more major infections and herpesvirus infections compared with chlorambucil-treated patients.

Rituximab-based chemotherapy for steroid-refractory autoimmune hemolytic anemia of chronic lymphocytic leukemia.

Autoimmune hemolytic anemia (AIHA) is a well known complication of chronic lymphocytic leukemia (CLL). Steroids are the first line of treatment and there are limited effective treatment options for steroid refractory AIHA of CLL. Rituximab, an active agent against B cell malignancies, has also been noted to be active in certain autoimmune hematologic disorders. We used a combination of rituximab, cyclophosphamide and dexamethasone (RCD) in eight CLL patients with steroid refractory AIHA. Rituximab was given at a dose of 375 mg/m(2) i.v. on day 1 (D-1). Cyclophosphamide was given at a dose of 750 mg/m(2) on D-2. Twelve mg of dexamethasone was given i.v. on D-1, D-2 and orally from D-3 to D-7. Cycles were repeated every 4 weeks till the best response. Response in AIHA was evaluated by frequent blood counts and Coombs test. All eight patients achieved a remission of their AIHA. Median pretreatment hemoglobin was 8.3 g/dl and post-treatment hemoglobin was 14.3 g/dl. Five patients converted to Coombs negative after RCD. Median duration of response was 13 months (7-23+). Retreatment with RCD was also effective in achieving a response on relapse of AIHA. Our results indicate that a rituximab-based combination regimen (RCD) is highly effective in treating steroid refractory AIHA of CLL.

Impaired interferon alpha response in hairy cell leukemia is corrected by therapy with 2-chloro-2'-deoxyadenosine: implications for susceptibility to opportunistic infections.

Patients with hairy cell leukemia (HCL) are susceptible to opportunistic intracellular infections, suggesting defects in cellular immunity. Prior studies have indicated an association between failure of IFN-alpha generation by peripheral blood mononuclear cells (MNC) and susceptibility to such infections. We here present results on IFN-alpha generation in HCL patients pre- and post-therapy. Prior to treatment with 2-chloro-2'-deoxyadenosine (CdA), MNC from 24 HCL patients with active disease produced little or not IFN-alpha (geometric mean < 40 IU/ml) compared with controls (n = 140, geometric mean 1730 IU/ml, p < 0.0005). After treatment with CdA, IFN-alpha generation was studied in 16 patients, with a geometric mean value of 650 IU/ml (p < 0.0005 compared with pre-CdA levels). The severe depression of IFN-alpha generation improved progressively following CdA therapy-induced clinical remission. We propose that deficiency of IFN-alpha production may play a role in the susceptibility to intracellular infections of patients with active HCL.

Recombinant alpha-2b-interferon in therapy of previously untreated hairy cell leukemia: long-term follow-up results of study by Cancer and Leukemia Group B.

In 1985, Cancer and Leukemia Group B initiated a multi-institutional study to define the role of interferon alpha in therapy of previously untreated active hairy cell leukemia (HCL). This is a long-term follow-up report of the study. Fifty-five evaluable patients were treated with recombinant interferon-2b 2 million units/m2 subcutaneously three times a week for 1 year. Treatment was well tolerated; toxicity mainly consisted of flu-like syndrome and pancytopenia, both of a transient nature. Seventy-three percent of patients had objective beneficial responses with 8.3 months median time to achieve at least a partial response (PR). After 1 year of therapy, the patients have been observed for a median of 5 years. There was a continual trend towards relapse throughout this period but 28% have remained in remission beyond 6 years. Forty-six patients (83%) are alive at 6 years. Among the 40 patients who achieved at least a PR, there were 28 with splenomegaly at the beginning of study: the spleen size was reduced in all with interferon alpha therapy and none required splenectomy. This study confirms the results of other investigators, and demonstrates that recombinant alpha interferon-2b is an effective agent for treatment of hairy cell leukemia.

The induction of p53 and WAF1/CIP1 in chronic lymphocytic leukemia cells treated with 2-chlorodeoxyadenosine.

The treatment of chronic lymphocytic leukemia includes the use of alkylating agents, steroids, and more recently nucleoside analogues. While prior studies have described potential mechanisms of 2-chlorodeoxyadenosine cytotoxicity including the accumulation of DNA strand breaks and induction of apoptosis or programmed cell death, the expression of p53 and its downstream target WAF1/CIP1 have not been examined. In this report we describe the induction of p53 and WAF1/CIP1 in the apoptotic chronic lymphocytic leukemia cells after exposure to 2-chlorodeoxyadenosine.

Future strategies toward the cure of indolent B-cell malignancies. New biologic therapies.

Although chronic lymphocytic leukemia (CLL) cells provide an excellent target for antibody therapy, to date this approach has met with limited success in patients with CLL. Promising data are emerging with a new generation of antibodies, such as Campath-1H, which may offer effective therapeutic options not only as single agents but also in combination with such drugs as fludarabine. Other new antibodies, including rituximab and several new radioimmunoconjugates, have provided impressive results in the indolent non-Hodgkin's lymphomas and warrant further investigation.

Prognostic factors in chronic lymphocytic leukemia.

The Rai staging system is widely used and is easy to apply in clinical practice. The system introduced by Binet et al offers an advantage that it consists only of three stages and, therefore, is more practical for initiation of controlled therapeutic trials than the five-stage Rai system. However, when we take into consideration the survival curves, it is important to note that the Rai system has three groups (and not five), low risk (stage O), intermediate risk (stages I and II), and high risk (stages III and IV). These groups are roughly equivalent to Binet's A, B, and C stages, respectively. Although the IWCLL has recommended a unified, integrated method of combining Binet and Rai systems, in practice, however, such a combination is cumbersome and unusable. Both systems, however, suffer from an important limitation--they cannot predict for the large majority of patients in the low and intermediate risk groups (Binet's stages A and B and Rai's O, I, and II) who will have an indolent course and good prognosis in contrast to those in the same stages whose disease will progress rapidly. It is necessary, therefore, to combine the bone marrow histology findings, the lymphocyte doubling time and the threshold values of blood lymphocyte count with the clinical staging systems to distinguish between indolent disease course and aggressive disease on a prospective basis within a given clinical stage.

Cladribine for the treatment of hairy cell leukemia and chronic lymphocytic leukemia.

Cladribine (Leustatin; Janssen-Cilag, Ortho Biotech Inc, Raritan, NJ) is a novel injectable nucleoside analogue with marked efficacy against hairy cell leukemia and considerable, although less dramatic, activity against chronic lymphocytic leukemia and non-Hodgkin's lymphoma. The effect is thought to be due to the drug's ability, after intracellular phosphorylation, to inhibit repair of single-strand DNA breaks in certain malignant lymphocyte and monocyte subtypes. We treated 49 patients with active hairy cell leukemia with continuous infusion of cladribine at a dose of 0.1 mg/kg/ d for 7 days. A single course of therapy gave a complete response rate of 76% and a partial response rate of 24%; the effect was durable for several years in most cases. We also treated 14 patients with chronic lymphocytic leukemia with cladribine and obtained an overall response rate of 43%; this required several courses of monthly treatment. These responses tended to be short-lived and did not substantially change life expectancy of chronic lymphocytic leukemia patients. In both diseases, myelosuppression and immunosuppression, sometimes resulting in neutropenic fever, were the only toxicities associated with cladribine.

Old and new therapies in chronic lymphocytic leukemia: now is the time for a reassessment of therapeutic goals.

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia for which therapeutic options remain unsatisfying as cure has remained elusive. Recent laboratory discoveries and promising results from completed phase III studies with fludarabine provide reason to reassess therapeutic goals in the treatment of patients with symptomatic CLL. Early enrollment of patients on protocols using combination therapies with fludarabine and new agents such as flavopiridol, IDEC-C2B8, Campath-1H, UCN-01, bryostatin, FR 901228, and melarsoprol will hopefully represent the next advance to improved overall survival and ultimately the cure of CLL.

Mediastinal irradiation for chronic lymphocytic leukemia.

Thirty-one patients with chronic lymphocytic leukemia were treated with mediastinal radiation. In none of the patients was complete remission achieved; either partial remission or clinical improvement was achieved in 52 per cent, but the duration of response was short. The response rate was 77 per cent for the patients receiving a total radiation dose greater than 3,000 rads and 45 per cent for those receiving less than 3,000 rads. Severe life-threatening toxicity was noted in 11 patients and seven of these patients died; two patients died with progressive disease. Severe toxicity was manifested by one or more of the following: bone marrow aplasia, pancytopenia, gram-negative sepsis, generalized herpes zoster and severe esophagitis. Neither the total dose of radiation nor the dose per week correlated withe the severity of reaction or death.

5th International Workshop on Chronic Lymphocytic Leukemia.

In the past few years important advances have been made in our understanding of the biology and natural history of CLL; also, new strategies and agents offer promise in the treatment of this form of leukemia. Now, patients can be treated on a more rationale basis and with real prospects for a sustained control of their disease, and improved quality of life. Hopefully, progresses in CLL will continue to accumulate in the coming years.

Delphi-panel analysis of appropriateness of high-dose therapy and bone marrow transplants in adults with acute lymphoblastic leukemia in first remission.

BACKGROUND: There is controversy over whether high-dose therapy and a bone marrow transplant is better than conventional-dose chemotherapy in adults with acute lymphoblastic leukemia (ALL) in first remission. This decision may depend on which type of donor is available: an HLA-identical sibling, an alternative donor transplant (HLA-matched related or unrelated people other than HLA-identical siblings), or autotransplant. OBJECTIVE: To determine the appropriate use of high-dose therapy and bone marrow transplants in ALL in first remission. Develop a treatment algorithm. PANELISTS: Nine leukemia experts from diverse geographic sites and practice settings. EVIDENCE: Boolean MEDLINE searches of acute lymphoblastic leukemia and chemotherapy and/or transplants. CONSENSUS PROCESS: We used a modified Delphi-panel group judgment process. Age, white blood cell (WBC) count, cytogenetics and immune type were permuted to define 48 clinical settings. Each panelist rated appropriateness of high-dose therapy and a transplant versus conventional-dose chemotherapy on a 9-point ordinal scale (1, most inappropriate; 9, most appropriate) considering three types of donors: (1) HLA-identical siblings; (2) alternative donors; and (3) autotransplants. An appropriateness index was developed based on median rating and amount of disagreement. Relationship of appropriateness indices to the permuted clinical variables was considered by analysis of variance and recursive partitioning. Preference between donor types was analyzed by comparing mean appropriateness indices of comparable settings and a treatment algorithm was developed. CONCLUSIONS: In people with an HLA-identical sibling donor, transplants were rated appropriate in those with unfavorable cytogenetics and uncertain in all other settings. An HLA-identical sibling donor was always preferred to an alternative donor or autotransplant. In people without an HLA-identical sibling but with an alternative donor, this type of transplant was rated appropriate in those with unfavorable cytogenetics. However, an autotransplant was preferred over an alternative donor transplant in all other settings where a transplant was rated uncertain. In people without an HLA-identical sibling or alternative donor, autotransplants were rated uncertain in all settings except in those with not unfavorable cytogenetics, WBC < 100 x 10(9) l(-1) and T- or pre-B-cell type where they were rated inappropriate.

Delphi-panel analysis of appropriateness of high-dose therapy and bone marrow transplants in adults with acute myelogenous leukemia in 1st remission.

BACKGROUND: Despite considerable data, there is still controversy over which adults with acute myelogenous leukemia (AML) in 1st remission should receive high-dose therapy and a bone marrow transplant rather than conventional-dose chemotherapy. Analyses of data from randomized trials are complex, conclusions sometimes contradictory and results not sufficiently detailed to allow subject-level decisions. OBJECTIVE: To determine appropriate use of high-dose therapy and bone marrow transplants in persons with AML in 1st remission with specific features. Develop a treatment algorithm. PANELISTS: Nine leukemia experts from diverse geographic sites and practice settings. EVIDENCE: Boolean MEDLINE searches of acute myelogenous leukemia and chemotherapy and/or transplants. CONSENSUS PROCESS: We used a modified Delphi-panel group judgment process. Age, WBC, cytogenetics and FAB-type were permuted to define 72 clinical settings. Each panelist rated appropriateness of high-dose therapy and a transplant versus conventional-dose chemotherapy on a nine-point ordinal scale (1, most inappropriate, 9, most appropriate) considering 3 types of donors: (1) HLA-identical siblings; (2) alternative donors (HLA-matched related or unrelated people other than an HLA-identical sibling); and (3) autotransplants. An appropriateness index was developed based on median rating and amount of disagreement. The relationship of appropriateness indices to the permuted clinical variables was considered by analysis of variance and recursive partitioning. Preference between donor types was analyzed by comparing mean appropriateness indices of comparable settings and a treatment algorithm developed. CONCLUSIONS: In people with an HLA-identical sibling, this type of transplant was rated appropriate in those with unfavorable cytogenetics and uncertain in all other settings. In people without an HLA-identical sibling, an alternative donor transplant was rated appropriate in those < 30 years with unfavorable cytogenetics, uncertain in those > 30 years and unfavorable cytogenetics and inappropriate in all other settings. Autotransplants were rated appropriate in people with unfavorable cytogenetics and uncertain in all other settings. An HLA-identical sibling donor, when available, was always preferred to an alternative donor transplant or autotransplant. In people without an HLA-identical sibling, an autotransplant was almost always favored over an alternative donor transplant with the magnitude of preference inversely correlated with transplant appropriateness.

Delphi-panel analysis of appropriateness of high-dose therapy and bone marrow transplants in chronic myelogenous leukemia in chronic phase.

BACKGROUND: It is uncertain which people with chronic myelogenous leukemia (CML) in chronic phase should receive conventional treatment (interferon and/or chemotherapy) versus high-dose therapy and a bone marrow transplant. There are no randomized trials comparing these approaches and analyses of data from non-randomized studies are complex, contradictory without sufficient detail to allow subject-level treatment decisions. OBJECTIVE: Determine appropriateness of high-dose therapy and bone marrow transplants in persons with CML in chronic phase with specific features. Develop a treatment algorithm. PANELISTS: nine leukemia experts from diverse geographic sites and practice settings. EVIDENCE: Boolean MEDLINE searches of chronic myelogenous leukemia and chemotherapy and/or transplants. CONSENSUS PROCESS: We used a modified Delphi-panel group judgment process. Age, prognostic score, disease duration, and type of conventional therapy and response were permuted to define 90 clinical settings. Each panelist rated appropriateness of high-dose therapy and a transplant versus conventional therapy on a 9-point ordinal scale (1, most inappropriate, 9, most appropriate) considering three types of donors: (1) HLA-identical siblings; (2) alternative donors (HLA-matched related or unrelated people other than an HLA-identical sibling); and (3) autotransplants. An appropriateness index was developed based on median rating and amount of disagreement. Relationship of appropriateness indices to permuted clinical variables was considered by analysis of variance and recursive partitioning. Preference between donor types was analyzed by comparing mean appropriateness indices of similar settings and a treatment algorithm developed. CONCLUSIONS: In people with CML in chronic phase and an HLA-identical sibling donor and in those with an alternative donor (but no HLA-identical sibling), a transplant was rated appropriate in those with a < or = partial cytogenetic response to interferon and uncertain or inappropriate in all other settings. Autotransplants were rated uncertain or inappropriate in all settings. Most of the variance in appropriateness ratings between different clinical settings was accounted for by response to interferon: complete versus < or = partial response. An HLA-identical sibling donor, when available, was always preferred to an alternative donor or autotransplant. In people without an HLA-identical sibling, an alternative donor was favored over an autotransplant at higher appropriateness indices and the converse at lower appropriateness indices.

Management of chronic lymphocytic leukemia.

Significant progress has been made in the past two decades in the understanding of immunobiology of CLL and the development of clinical staging systems and identification of other prognostic factors in CLL. A significant advance in the management of CLL has also been made. Now we know when to initiate therapy. We recommend that patients with stage 0 and patients with stages I and II associated with good prognostic features such as absence of disease-related symptoms, long lymphocyte doubling time, nondiffuse bone marrow infiltration, and low tumor load not be treated; they should be followed at 2- to 6-month intervals. We recommend initiation of therapy for patients with stages I and II, associated with poor prognostic features such as presence of disease-related symptoms, short lymphocyte doubling time, diffuse bone marrow infiltration, and high tumor load and for patients with stages III and IV. However, we still do not know what constitutes the optimal therapy for the disease. In one large randomized study, the response rate as well as survival superiority of CHOP (with low-dose Adriamycin) over COP in previously untreated patients with stage C disease was observed. In another large randomized study, only a response rate advantage of CHOP (with standard dose Adriamycin) over chlorambucil and prednisone (in previously untreated patients with stages B and C) was seen. No randomized studies have compared CHOP versus chlorambucil and prednisone in patients with stages III and IV or stage C. At present, our recommendation for the treatment of patients with advanced disease is chlorambucil and prednisone therapy. New drugs under clinical trials for CLL include (1) deoxycoformycin, (2) 2-chlorodeoxyadenosine, and (3) fludarabine monophosphate. Both deoxycoformycin and 2-chlorodeoxyadenosine have been shown to have some activity in previously treated CLL patients with advanced disease. The effectiveness of these agents, however, has not been tested yet in untreated patients with advanced disease. Fludarabine monophosphate, on the other hand, has been shown to be very effective in both previously treated and untreated patients with advanced disease. Allogeneic bone marrow transplantation recently has been found to be of benefit in some patients (37 to 46 years) in a preliminary study; this therapeutic procedure should be tested further in a larger population of younger patients (less than 50 years) with advanced CLL. New agents such as lymphokines (interferons and IL-2) and monoclonal antibodies have been investigated for their efficacy and found to be minimally effective in previously treated patients with advanced disease.(ABSTRACT TRUNCATED AT 400 WORDS)