Interferon alfa as primary treatment of chronic myeloid leukemia: long-term follow-up of 71 patients observed in a single center.

The purpose of this study was to evaluate the long-term outcome of interferon (IFN) alfa treatment in patients with Philadelphia chromosome-positive chronic myeloid leukemia (CML). Between 1984 and 1990, a total of 71 patients with newly diagnosed CML had been enrolled into two consecutive IFN trials at our institution. Follow-up extended to December 1998, resulting in a median observation period for surviving patients of 11.4 years. The median survival time from diagnosis was 5.9 years. A plateau in the actuarial survival curve was found from 8.2 to 12.3 years following diagnosis with a projected 10-year survival rate of 32%. 'Landmark' studies showed a significant survival advantage for patients with karyotype responses. Of 68 patients accessible to calculation of the Hasford score, three were in the high risk group, 24 belonged to the medium risk group, and 41 had low risk features. The majority of cytogenetic responders including all eight assessable patients in complete cytogenetic remission were in the low risk group. Achieving a cytogenetic remission was found to provide a survival advantage also for patients with low risk disease. Of the seven patients surviving more than 11 years, six were in continuous complete cytogenetic remission. Their favorable outcome appears to translate into an out-flattening of the survival curve for the 71 single center patients presented. It will be of interest to see whether prolonged follow-ups of the large multicentric randomized trials will similarly show a subset of long-term surviving patients with ongoing IFN-induced remission.

Breakpoint localization within the M-bcr and clinical course do not correlate in patients with chronic myelogenous leukemia undergoing alfa interferon therapy.

The breakpoint localization was analyzed in 61 patients with Philadelphia chromosome (Ph) positive chronic myelogenous leukemia to compare the breakpoint localization and clinical course. All patients were treated with interferon alfa (IFN alpha) or IFN alpha plus IFN gamma at the time of the study. Thirty-three of the patients had been pretreated with other cytostatic drugs. Sixty-nine per cent of the breakpoints were located in the 5' region of the major breakpoint cluster region (M-bcr), 29% in the 3' part. There was no significant difference between these two groups with respect to response to IFN(s), clinical course or conversion to blast crisis, nor survival.

Bcr-abl-positive and -negative clonogenic cells in CML patients undergoing long-term interferon treatment.

Bone marrow (BM) and peripheral blood cell (PBC) samples of 11 Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) patients in long-lasting hematologic remission induced by interferon (IFN) treatment were examined for the presence of leukemic hematopoietic precursor cells. Southern blot analysis revealed residual leukemic cells in BM samples of four patients, whereas seven patients showed no aberrant bands. Reverse transcription polymerase chain reaction (RT-PCR), however, amplified bcr-abl-specific cDNA in unfractionated BM or PBC samples in all 11 patients. The patients demonstrating bcr rearrangements in Southern blots had either a mosaic pattern (three patients) of bcr-abl-negative and positive colony-forming precursors (CFU-GEMM, BFU-E, CFU-GM, CFU-Mega), or all colonies were derived from leukemic precursors (one patient). However, in soft agar cultures of four patients without aberrant bands in Southern blots, only colonies without amplifiable bcr-abl transcripts were detectable. In another patient, few bcr-abl-positive colonies were found after 44 months of treatment, but not after 53 and 56 months of therapy. In these patients, therefore, residual disease detectable by PCR analysis of unfractionated cell samples does not appear to reside in the colony-forming cell compartment. The prognostic implications of these observations and the nature of the remaining bcr-abl-positive cells within unfractionated cell samples remain to be determined.

A multicenter trial of interleukin-2 and low-dose cyclophosphamide in highly chemotherapy-resistant malignancies.

The anti-tumor activity of high-dose recombinant interleukin-2 (IL-2) has been demonstrated in several recent preclinical and clinical studies. In an attempt to study possible synergistic effects with low-dose cyclophosphamide (CYC), a phase II clinical trial was initiated in 32 patients, 18 with malignant melanoma (MM) and 14 with renal cell carcinoma (RCC). The recombinant IL-2 (Cetus Corp., Emeryville, Ca, U.S.A.) was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for five days twice in cycles II and III, respectively; if tolerated, the dose was escalated to a maximum of 6 x 10(6) U/m2/day; the cycles, separated by 1-week treatment-free intervals, were each preceded by a single i.v. bolus of CYC at 350 mg/m2. The most prominent side-effects encountered in this trial consisted of a capillary leak syndrome, myalgia and fever requiring dose reduction in half of the patients during the first cycle. Given the limit of tolerable toxicities in a standard care unit, the regimen employed achieved minor anti-tumor activity. No objective responses were achieved in patients with RCC and a 15% remission rate (PR + MR) was seen in melanoma patients.

Interferon alfa-2b in acute- and chronic-phase chronic myelogenous leukaemia: initial response and long-term results in 54 patients.

Fifty-four patients with Ph1-positive chronic myelogenous leukaemia (CML) (48 with chronic-phase and six acute-phase disease) were treated with interferon alfa-2b subcutaneously (s.c.). The starting dose was 4 million units (MU)/m2 body surface area daily. It was reduced in parallel with serially determined leucocyte counts, and minimal effective doses were given as maintenance after achieving remission. Haematological remissions were induced in 22 of the 48 patients (46%) with chronic-phase disease. Thirteen patients (27%) revealed partial haematological remission and another 13 no response to treatment. No complete remission could be induced, although minor or partial cytogenetic responses were seen in 16 patients (33%). Moreover, a bcr-abl reduction was detected on Southern blot analysis in two patients. In chronic-phase disease, results of treatment were influenced by elapsed time after diagnosis, extent of previous treatment and interferon dosage. No beneficial effects of interferon were detected in the six patients with acute-phase disease. Principal acute side effects were fever and flu-like symptoms at the beginning of the therapy, which usually subsided within 3-7 days. Chronic side effects, especially weakness and neuropathy, were less frequent but more severe and necessitated discontinuation of treatment in 10 patients. In summary, interferon alfa-2b seems to be an effective treatment in early chronic-phase CML. Long-term effects on the course of the disease, however, must be determined.

Bleomycin, vincristine, lomustine and dacarbazine (BOLD) in combination with recombinant interferon alpha-2b for metastatic uveal melanoma.

This EORTC multicentre study analysed the efficacy and tolerability in patients with metastatic uveal melanoma of BOLD chemotherapy in combination with recombinant interferon alpha-2b. The dose of bleomycin was 15 mg on days 2 and 5, of vincristine 1 mg/m(2) on days 1 and 4, of lomustine 80 mg on day 1, and of dacarbazine (DTIC) 200 mg/m(2) on days 1-5, given every 4 weeks for a minimum of two cycles. Subcutaneous (s.c.) interferon alpha-2b at a dose of 3 x 10(6) IU was initiated on day 8 of the first cycle, and continued at a dose of 6 x 10(6) IU three times per week after 6 weeks. A median of two cycles were administered to 24 patients (median age 60.5 years). None achieved an objective response (0%; 95% Confidence Interval (CI): 0-14), 2 (8.3%) remained stable, 20 showed progression, and 2 (8.3%) were invaluable. The median progression-free survival was 1.9 months (95% CI: 1.8-3.4) and overall survival 10.6 months (95% CI: 6.9-16.4). Overall survival improved with increasingly favourable pretreatment characteristics (median, 14.7 versus 6.9 versus 6.0 months for Helsinki University Central Hospital (HUCH) Working Formulation stages IVBa, IVBb and IVBc, respectively; P=0.018). Grade 3 alopecia and neurotoxicity occurred in 13% of the patients. This multicentre study did not confirm earlier reports that BOLD with human leucocyte or recombinant interferon would induce at least 15% objective responses in metastatic uveal melanoma.

Interferon alfa-2b in the treatment of chronic myelogenous leukemia.

Thirty-six patients with Philadelphia chromosome-positive CML were treated with interferon alfa-2b for at least 3 months. Thirty-two of the patients had chronic phase disease and four had acute phase disease, one in blast crisis. Patients initially received a daily dose of 4 megaunits/m2 administered subcutaneously; outpatient self administration followed at a dosage decreased in accordance with serially determined blood cell counts. Treatment was continued for 0.5 to 15 months, with a median duration of 7 months. No complete remission was achieved, but hematologic remission occurred in 21 (58%) patients, with partial hematologic remission in an additional 12 (33%). All four patients with acute phase disease failed to respond. Adverse reactions were only significant during the first days of treatment and did not interfere with self administration of the drug. Interferon alfa-2b may prove to be an important alternative therapeutic modality in chronic phase CML.

Treatment of chronic myelogenous leukemia with different cytokines.

In vitro data suggest a synergistic antiproliferative effect of different cytokines. In four clinical studies chronic myelogenous leukemia (CML) patients were treated with interferon (IFN)-alpha alone or IFN-alpha combined with either low-dose IFN-gamma or tumor necrosis factor (TNF)-alpha. The best response was achieved in previously untreated patients with good prognostic factors and highest tolerable IFN dose for maintenance treatment. Breakpoint localization within the major breakpoint cluster region did not correlate with response to IFN. In a randomized study of IFN-alpha versus IFN-alpha combined with IFN-gamma, no differences in response rates were observed. Patients with primary or secondary resistance to these treatment modalities received a combination therapy with IFN-alpha and TNF-alpha. In these patients, a decrease in leukocyte counts was noted, but no cytogenetic improvement occurred.

Ifosfamide, methotrexate, and 5-fluorouracil in advanced pretreated breast cancer.

Thirty-five patients with a median age of 55 years (range, 28 to 68 years) and a median Karnofsky status of 80% (range, 40% to 100%) were treated with ifosfamide (1.5 g/m2 plus mesna), methotrexate (40 mg/m2), and 5-fluorouracil (600 mg/m2) intravenously (IV) days 1 and 8 at intervals of 4 weeks. Thirty-four patients had received previous chemotherapy, including anthracyclines in 28 patients. All patients were evaluable for response. A partial remission was achieved in six patients (17%), stable disease in 13 patients (37%), and 16 patients (46%) were unresponsive. Median time to progression was 7 months (range, 4 to 13 months) for partial responders, and 4 months for patients with stable disease. Median survival was 9 months for all patients, 13 months for partial responders, 16 months for no change, and 3 months for progressive disease. Toxicity was tolerable, with myelotoxicity being a dose-limiting factor, mainly in heavily pretreated patients. No treatment-related death occurred. In conclusion, this combination is effective and well tolerated. Ifosfamide is suggested for further evaluation in advanced breast cancer.

Epirubicin and ifosfamide in metastatic breast cancer.

In a randomized, phase II trial, we evaluated the effectiveness of continued chemotherapy with epirubicin/ ifosfamide versus unmaintained treatment interruption in advanced metastatic breast cancer. Three hundred fifty-seven patients were enrolled and 331 were evaluable for response. Complete response was achieved in 25 patients (8%) and partial response in 121 patients (37%). Pretreatment status correlated significantly with response (complete and partial response). While 54% of unpretreated patients responded, only 42% of the patients responded who had been pretreated with adjuvant chemotherapy and 33% who had been pretreated in the metastatic stage of disease; 69 patients (21%) had disease progression. Of 11 patients pretreated in both the adjuvant and metastatic setting, only two responded. Toxicity of treatment was mild, with leukopenia being the treatment-limiting factor. Thrombocyte levels were not altered significantly by treatment. Thus, there seems to be room for dose escalation using granulocyte colony-stimulating factor. There was no considerable cardiotoxicity, central nervous system toxicity, or cystitis observed. The low rate of cardiotoxicity appeared to be related to dose fractionation of epirubicin. After randomization of patients to treatment interruption versus continuation of chemotherapy, a longer relapse-free survival was observed for patients who continued chemotherapy (mean relapse-free survival, 2+ months); however, this did not translate into prolonged survival. The cumulative scores of toxicity and quality of life parameters showed increasing superiority for treatment interruption. Therefore, a strategy of treatment until maximum response and subsequent treatment interruption seems to be superior to treatment continuation.

Modulation of the antigraft response by preimmunization. Lack of correlation between regulatory events and graft survival.

Using two H-2 congeneic mouse strain combinations, the effect of donor specific i.v. preimmunizations with allogeneic spleen cells was studied. Parameters analyzed were survival time of the subsequent skin graft, graft-induced delayed-type hypersensitivity (DTH) reactions, and humoral immune responses evoked by immunization and grafting. Depending on the dose of allogeneic cells used for preimmunization, a suppression of the DTH response was observed, commonly accompanied by a similarly dose-dependent antibody formation that was inversely related to the DTH response. Neither DTH reactivity nor the antibody response were correlated in this system with the survival time of the skin graft. The only modulation of the survival time to be observed was an accelerated rejection of the graft caused by nonirradiated, as compared with irradiated, donor spleen cells. The data are discussed with regard to the clinically observed effect of blood transfusions on the survival of renal transplants and the relationship between DTH and graft rejection.

Rapamycin antagonizes interleukin-6 mediated growth arrest and differentiation of myeloblastic M1 cells.

The immunosuppressant rapamycin is known to be a potent inhibitor of cytokine driven proliferation of T-lymphocytes and other cell types. Here we have examined the effect of rapamycin on the myeloblastic cell line M1 which responds to interleukin-6 (IL-6) with growth arrest and monocytoid differentiation. Single-agent rapamycin led to a retardation of M cell growth. In spite of this intrinsic antiproliferative effect, rapamycin was found to abrogate IL-6 induced growth arrest. Concomitant exposure to rapamycin and IL-6 also reduced the extent of monocytoid differentiation as compared to treatment with IL-6 alone. Excess levels of the FK-506 analogue ascomycin reversed the antagonistic effect of rapamycin on IL-6 mediated growth suppression, suggesting that this biological action of rapamycin is mediated by a rapamycin/immunophilin complex. The findings demonstrate that rapamycin can also act as an antagonist of cytokine induced growth arrest and differentiation.

Analysis of the novel cyclin-dependent kinase 4 and 6 inhibitor gene p18 in lymphoma and leukemia cell lines.

The genes for the CDK4/6-inhibitors p16INK4A/MTS1 and p15INK4B/MTS2 are frequently deleted in hematological malignancies. A new member of this family of CDK4/6 inhibitors is p18. In order to assess p18 growth-suppressor gene alterations in hematological neoplasms, we investigated 31 lymphoma and leukemia cell lines by PCR for both exons of this gene. No homozygous deletions were observed. Investigation of a new intragenic restriction fragment length polymorphism revealed no differences in allele distribution between the tumor cell lines and healthy volunteers. Our results suggest that homozygous deletion of the p18 gene does not play a major role in leukemogenesis or lymphomagenesis.

DNA-flow cytometry studies in blood and marrow cells from chronic myelogenous leukemia patients treated with interferon alpha-2b.

Cell cycle distribution in bone marrow and peripheral blood mononucleated cells was studied in patients with chronic myelogenous leukemia (CML) before and during treatment with interferon (IFN) alpha-2b. DNA-flow cytometry with ethidium bromide fluorescence was used. Highly significant differences between mononucleated cells from CML patients and normal controls were seen in peripheral blood but not in bone marrow specimens. Patients achieving hematologic remission during IFN treatment showed a cell cycle distribution in bone marrow cells and peripheral blood cells similar to normal controls.

No correlation between site of breakpoint in the BCR gene and platelet counts in Philadelphia chromosome-positive CML.

In chronic myelogenous leukemia (CML) malignant cells are characterised by the Philadelphia chromosome (Ph), resulting from a translocation t(9;22). The position of the breakpoint within the major breakpoint cluster region (M-bcr) on chromosome 22 has been shown to correlate with the clinical course of the disease or, more recently, thrombopoietic activity. We have therefore determined the breakpoint localisation in 53 Ph-positive CML patients. Following the 5'/3'-region definition of Inokuchi et al. Leukemia Research 15, 1067 (1991) [1], 22 of our patients have 5' and 31 of our patients have 3' orientated breaks. No correlation was found between platelet counts and breakpoint localisation.

Frequency of clonal B lymphocytes in chronic myelogenous leukemia evaluated by fluorescence in situ hybridization.

The demonstration of the Philadelphia (Ph) chromosome in B lymphocytes from patients with chronic myelogenous leukemia (CML) has provided evidence that the disorder originates in a pluripotent progenitor cell. Divergent results, however, exist as to the degree of contribution of clonally derived cells to the B-cell compartment. To address this issue, B lymphocytes were selected from the blood of seven patients in the chronic phase of Ph-positive CML and were examined with dual-color fluoresence in situ hybridization for the presence of the Ph translocation. The purity of the B-cell preparations ranged from 88% to 97% (mean 93%). The Ph translocation was detected in 22-34% (mean, 27%) of the sorted B cells. There was no evidence that the duration of the disease affects the ratio of Ph-positive and -negative B cells. In summary, clonally derived circulating B lymphocytes were present in all patients studied but made only minor contribution to this compartment.

Long-term treatment of chronic myelogenous leukemia with different interferons: results from three studies.

131 patients with Philadelphia (Ph') chromosome positive chronic myelogenous leukemia (CML) were treated with interferon (IFN) alpha or a combination of IFN alpha and IFN gamma. In study, 1, 13 not pretreated and 41 pretreated patients, 48 in chronic phase disease, 6 in accelerated phase, received 4 x 10(6) U/m2 IFN alfa-2b initially. After achievement of hematologic remission, the individually minimum effective dose was used for maintenance. There was no response in acute phase disease. Of the 48 patients with chronic phase disease, 22 achieved a hematologic remission (HR), 13 a partial HR (PHR), and 13 did not respond (NR) to IFN. No major cytogenetic response occurred in these patients, but two patients achieved a major molecular response in Southern blots, whereas PCR tests were positive. In a further randomized study, CML patients without prior therapy were treated initially with 4 x 10(6) U/m2 IFN alpha alone (arm A) or in combination with 50 micrograms IFN gamma (arm B). For maintenance, the maximum tolerable dose of IFN alpha was given (up to 10 x 10(6) U/day). Thirteen patients in arm A (54%) and 14 (56%) patients in arm B achieved a HR, 7 patients (29%) in arm A and 6 patients (24%) in arm B a PHR. No response could be induced in 4 patients (17%) of arm A and 5 patients (21%) of arm B. Major cytogenetic responses were observed in 5 (20%) patients of arm A and 5 patients (20%) of arm B. Major molecular responses were observed in 3 patients of arm A and 5 patients of arm B.(ABSTRACT TRUNCATED AT 250 WORDS)