Monitoring of remission status by fluorescence in situ hybridisation in chronic myeloid leukaemia patients treated with interferon-alpha.

Interferon-alpha (IFN-alpha) can be considered as treatment of choice for patients with chronic myeloid leukaemia (CML) in chronic phase. With this treatment major cytogenetic responses can be achieved in 30% to 50% of patients. Regular monitoring of cytogenetic response is essential for the therapeutic management of these patients. As conventional cytogenetics is not always successful, especially under IFN-alpha treatment, molecular cytogenetic methods have been established for the examination of interphase nuclei for the presence of the BCR-ABL fusion gene, the molecular counterpart of the Philadelphia chromosome. To demonstrate the value of these new methods we have analysed interphase nuclei from sequentially cultured bone marrow cells from 14 CML patients who were treated with IFN-alpha and whose bone marrow was investigated regularly during therapy. Dual-colour FISH with a breakpoint spanning BCR-YAC and a flanking cosmid from the ABL region was applied. When compared with conventional cytogenetics the results achieved by FISH were favourable. The most evident advantage of FISH analysis is that in case of failure of conventional cytogenetics a reliable determination of the remission status can be done. Together with other recent studies our results illustrate the advantages and limitations of the interphase FISH method for monitoring CML patients.

Interferon-alpha-2C and LD ara-C for the treatment of patients with CML: results of the Austrian multi-center phase II study.

Small pilot studies of patients with CML have reported on encouraging response rates after treatment with interferon-alpha (IFNalpha) in combination with low-dose cytosine arabinoside (LD ara-C). We therefore initiated a multi-center phase II trial in order to investigate the efficacy and tolerability of this combination in newly diagnosed patients with Ph-positive chronic myelogenous leukemia (CML). Eighty-four patients were treated with IFN-alpha-2c at daily subcutaneous doses of 3.5 MU and LD ara-C added subcutaneously for 10 days every month at a dose of 10 mg/m2, following an initial reduction of WBC to less than 20 x 10(9)/l with hydroxyurea (HU). Within a median observation period of 28 (5-59) months the patients received a median of 7 (1-35) IFNalpha and LD ara-C cycles. Treatment was stopped due to side effects in 16 cases (19%) and to primary or secondary treatment failure in 38 cases (45%). In 45 patients (54%) complete hematological response (CHR) was achieved; in 39 patients (46%) cytogenetic responses including 15 (18%) complete cytogenetic responses (CHR) were observed. Median duration of cytogenetic responses was 15 months. Relapses were seen in 8/15 patients (53%) with complete cytogenetic remission (CCR), in 3/6 patients (50%) with partial cytogenetic response and in 9/18 patients (50%) with minor cytogenetic response. In conclusion, the combination of IFNalpha and LD ara-C resulted in encouraging rates of hematological and cytogenetic responses in patients with CML with low to moderate toxicity.

Interferon alpha-2c therapy of patients with chronic myelogenous leukemia: long-term results of a multicenter phase-II study. Austrian Biological Response Modifier (BRM) Study Group.

In a prospective multicenter phase-II trial 80 patients with Philadelphia (Ph)-positive chronic myelogenous leukemia (CML) were treated with recombinant interferon (IFN) alpha-2c, administered subcutaneously at an absolute dose of 3.5 megaunits (MU)/day. Complete hematological remission was achieved in 29 (39%) and partial hematological remission in 26 (35%) of the 74 patients evaluable for response. Major cytogenetic responses were observed in ten (13%) and minor cytogenetic responses in 11 patients (15%). Median duration of cytogenetic response was 33 months (range, 2-90); relapses were seen in all of the 11 patients with minor and in three of the ten patients with major cytogenetic responses. Median survival estimates for pretreated (n = 19) and untreated (n = 58) patients were 51 months (95% confidence interval [CI], 30-72) and 77 months (95% CI, 43-111), and the survival probabilities at 5 years were 45% and 54% for the two groups, respectively. Hematological response after 3 months of treatment demonstrated a clear-cut discriminative capacity with 5-year survival probabilities of 100%, 67% and 24% for patients achieving CHR (n = 6), PHR (n = 34), and less than PHR (n = 35), respectively. Landmark analysis at 12, 18, and 24 months after start of IFN therapy and an analysis treating time to cytogenetic response as a time-dependent covariate showed that cytogenetic response was associated with longer survival. The impact of a low-dose IFN regimen on survival in CML patients is unclear and requires further clarification by randomized clinical trials. Early hematological and cytogenetic response to IFN-alpha treatment identifies patients with a favorable long-term prognosis.

Treatment of 11 patients with chronic myelogenous leukemia with interferon-alpha-2C and low-dose cytosine arabinoside.

Patients with Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) and on interferon (IFN)-alpha-2c treatment for at least two months were entered in the present pilot study. IFN-alpha treatment was maintained identically and cytosine arabinoside (Ara-C) was added at monthly cycles of 10 mg/m2/day for ten days subcutaneously. In the case of a leukocyte nadir above 10 G/l, the Ara-C dose was increased to 20 mg/m2/day for 10 days per month. Ten of the eleven patients entered in this study were evaluable for toxicity and response. They received a total of 87 IFN-alpha/Ara-C cycles (3-14/patient). Five patients received 1-5 cycles with Ara-C dose intensification to 20 mg/m2/day. The following gastrointestinal and hematological toxicities were attributable to Ara-C, as they had not been observed in these patients during the preceding IFN-alpha monotherapy period. Gastrointestinal side effects consisted of nausea grade 1 (n = 5) and diarrhea grade 2 (n = 1). Hematotoxicity was observed in eight patients, grade 1 in five patients and grades 2, 3 and 4 in one of the patients each. Both episodes of grades 3 and 4 toxicity were seen during dose escalation to 20 mg/m2. Small cytogenetic responses (4-14%) were observed in 3 patients and a larger one (50%) in one patient, hematological improvement or stable disease in an additional three patients. These preliminary data suggest that the combination of IFN-alpha and low-dose Ara-C is active in inducing cytogenetic responses in CML patients at an acceptable rate of toxicity and therefore warrant further investigation.

Long-term follow-up of patients with hairy cell leukaemia treated with pentostatin: lymphocyte subpopulations and residual bone marrow infiltration.

Peripheral blood lymphocyte (PBL) subsets and bone marrow biopsies were analysed in six patients with hairy cell leukaemia (HCL) treated with 2'-deoxycoformycin (pentostatin, DCF) according to a phase II trial of the EORTC Leukemia Cooperative Group. All patients responded to DCF with four complete and two partial remissions according to conventional criteria. Within the PBL subsets, major changes concerned the CD4+ T cells, which during DCF therapy were distinctly suppressed to nadir values of 0.038-0.18 (median 0.126) x 10(9)/l. In five patients these cells returned to normal 3.0-49.5 (median 14.5) months after the last DCF injection. CD8+ cells were decreased to a lesser extent, and NK cell numbers improved during treatment. Bone marrow immunohistology applying the MoAb B-ly7 demonstrated residual hairy cells (HCs) in all of the six patients following DCF treatment with nadir HC numbers of 0.2-3.0% of bone marrow cells. Immunoglobulin gene rearrangement analysis of DNA obtained from these biopsies showed only germline bands, whereas rearranged bands had been present on the pretreatment specimens. Within the observation period of 15.5-54.0 (median 47.0) months after discontinuation of DCF therapy, immunohistology demonstrated a continuous increase in HC numbers in five of the six patients with clonal rearrangement detectable in bone marrow specimens from three of these patients at last follow-up date. Although established on the basis of a small number of patients, these data suggest that DCF treatment as currently employed in HCL is unable to eradicate the malignant B cell clone.

[Recombinant interferon alpha-2c in Ph-positive chronic myeloid leukemia. Results of a multicenter phase II study]. / Rekombinantes Interferon alpha-2c bei Ph-positiver chronischer myeloischer Leukämie. Ergebnisse einer multizentrischen Phase-II-Studie.

In a Phase II study, 82 patients with Philadelphia chromosome(Ph)-positive chronic myelogenous leukaemia were treated with 3.5 million I.U./d of recombinant interferon alpha-2c (rIFN). 73 patients have so far been evaluated (42 male, 31 female, mean age 50 [12-87] years). At the start of therapy, 10 were in the accelerated phase (group 1) and 63 in the chronic phase, of whom 19 had received previous treatment with cytotoxics (group 2), while the remainder (group 3, n = 44) had received primary treatment with rIFN. There was short-term stabilization in 7 of the 10 group 1 patients, but none had complete haematological or cytogenetic remission. In contrast, the remission rate (complete or partial haematological remission) was 63% in the previously treated (group 2) and 66% in the previously untreated chronic phase patients (group 3). There was a reduction in the proportion of Ph-positive metaphases in 7 group 2 patients (11%) and in 10 group 3 patients (23%). Complete cytogenetic remission has so far been seen in 2 patients. Cytogenetic improvement occurred after 3 months at the earliest, and in some patients only after 12 to 19 months treatment. Differences in response to treatment were related to stage (prognostic staging system of Kantarjian et al.) in group 3 patients: complete or partial haematological remission was seen in 22 out of 25 patients with stage 1 disease, in 4 out of 7 in stage 2, and in only 3 out of 12 in stages 3 and 4.