Follow-up of complete cytogenetic remission in patients with chronic myeloid leukemia after cessation of interferon alfa

PURPOSE

A small proportion of patients with chronic myeloid leukemia (CML) achieve a complete cytogenetic response (CCR), defined as the disappearance of Philadelphia (Ph) chromosome-positive metaphases, after treatment with interferon alfa (IFN). In this population of patients, the question of whether treatment should then be withdrawn is not yet resolved.

PATIENTS AND METHODS

In the present study, we followed 15 patients who stopped IFN after achieving CCR. In nine patients IFN was stopped in view of adverse reactions (n = 8) or patient's choice (n = 1). For the remaining six patients, the treatment was stopped because no BCR/ABL rearrangement could be detected by reverse transcriptase polymerase chain reaction (RT-PCR) in four successive analyses using peripheral-blood samples.

RESULTS

Loss of CCR and survival were not statistically different (P =.48; P =.7) for the 15 patients who stopped IFN compared with 41 other CCR patients who continued IFN therapy in our institution. The median follow-up after discontinuation of IFN treatment was 36 months (range, 6 to 108 months). Seven patients (47%) (females, or CCR > 24 months and RT-PCR negative before IFN cessation; P <.0001) did not relapse. Eight other patients (53%) relapsed (lost CCR) within 3 to 33 months of treatment discontinuation. One of them relapsed in major cytogenetic remission (MCR) and was still in MCR 87 months after stopping therapy without any treatment.

CONCLUSION

It is possible to stop IFN treatment at least in some patients with CML who achieve a prolonged period of CCR. This study also illustrates the hypothesis that persistence of low numbers of Ph-positive cells does not necessarily imply hematologic relapse.

Outcome of adult patients with acute myeloid leukemia who failed to achieve complete remission after one course of induction chemotherapy: a report from the BGMT Study Group

Between 50 and 75% of adult patients with de novo acute myeloid leukemia achieve complete remission (CR) but 25 to 40% of them require more than one course of induction chemotherapy to achieve CR. In order to investigate the impact of this situation on the overall outcome of patients we conducted a retrospective analysis of 130 patients, resistant to a single induction course from among three consecutive protocols, using the same induction regimen employed by the BGMT study group. This group of patients has a particularly poor prognosis with relapse and survival rates of 70% and 14% respectively at 5 years. For these patients, being in CR after two induction courses appears to be a major prognostic factor for outcome, since the 5-year Kaplan-Meier survival probability is significantly better (29%, range 17-46) than of those patients with resistant disease (5%, range 2-13). However, results are worse than when complete remission is obtained after a single course. Thus, post remission treatment should have a powerful anti-leukemic effect in preventing relapse. Allogeneic bone marrow transplantation is a preferential strategy in this setting but to be effective this should be performed as early as possible. Furthermore, these results indicate that allogeneic bone marrow transplantation from an alternative donor should be considered in the absence of HLA identical sibling.

Expression of interferon-α (IFN-α) receptor 2c at diagnosis is associated with cytogenetic response in IFN-α–treated chronic myeloid leukemia

For the management of chronic myeloid leukemia (CML), prediction or early determination of the response to interferon-alpha (IFN-α) treatment is important for identifying nonresponder patients to whom alternative therapy may be proposed. In this study, the levels of expression of both BCR-ABL and subunit 2c of IFN-α receptor (IFN-αR2c) genes were analyzed at diagnosis in 74 patients with chronic phase CML treated with an IFN-α monotherapy. By using blood samples, real-time quantitative polymerase chain reaction was performed to quantify BCR-ABL, IFN-αR2c, and G6PDH mRNA as external control. The results were compared with hematologic and cytogenetic responses to IFN-α. A wide variation in the BCR-ABL/G6PDH ratio was observed at diagnosis (median, 6.68%; range, 0.18%-41.31%), but no significant association with response to IFN-α was observed. In contrast, the variation of IFN-αR2c/G6PDH ratio at diagnosis was significantly associated with the achievement of major cytogenetic response (MCR; 34% or lower Ph+metaphases). Median values of IFN-αR2c/G6PDH ratio for patients achieving MCR and for those who did not achieve it were 110.75% (range, 9.47%-612.30%) and 64.42% (range, 5.96%-425.40%), respectively (P = .037). In addition, this novel molecular factor, combined with the achievement of complete hematologic response at 3 months, makes it possible to predict MCR achievement with high probability by Kaplan-Meier analysis (91% ± 17% at 24 months; P = .0001).

Allogeneic transplantation for patients with advanced acute leukemia: a single center retrospective study of 92 patients

Allogeneic transplantation is a well recognized treatment strategy of leukemia. However, its use in advanced leukemia patients is a subject of some debate especially when donors are not HLA-identical siblings because of the toxicity and cost of the procedure. We reviewed retrospectively the outcome of patients (pts) who received allogeneic transplantation for advanced acute leukemia in our center between 09/86 and 11/97. Thirty-six pts (study group) who lacked a matched sibling donor received partially matched related donor (n=14: PMRD group) or matched unrelated donor transplantation (n=22: MUD group). Fifteen pts had AML and 21 ALL. Seventeen pts (47%) were in CR>1, 13 pts (36%) had refractory disease and six pts (17.7%) were in untreated relapse. The outcome was compared to that of 56 patients (AML: 45.5 %, ALL: 55.5 %, CR>1: 49.9 %, refractory disease: 37.5 %, untreated relapse 19.6 %) who received allogeneic transplantation from a matched sibling donor (control group). Various conditioning regimens and GVHD prophylaxis were used. The actuarial incidence of grade II to IV acute GVHD was significantly higher in the study group (57%) than in the control group (34%) (p=0.047). The actuarial risk of relapse at three years was 21% +/- 22% in the study group versus 65% +/- 16% in the control group (p= 0.04). The actuarial probability of transplant-related mortality at 3 years is 64 +/- 16% for the study group and 25 +/- 11% for the control group (p=0.001). The leading cause of death in the study group was infection (30%) followed by acute GVHD and relapse. Relapse was the major cause of death in the control group (54%), followed by infection, interstitial pneumonia, veno-occlusive disease and GVHD. The OS and probability of leukemia-free survival at 3 years were 28 % +/- 15% (95% CI) and 27% +/- 15% (95% CI) in the study group. The overall survival and probability of LFS at 3 years were respectively 28 +/- 12% (95% CI) and 23 +/- 12% (95% CI) in the control group (p = 0.08 and p=0.11 respectively). In multivariate analysis, transplant-related mortality was higher in the study group (p=0.04) and lower if both donor and recipient were seronegative for CMV (p=0.007). OS was significantly higher for seronegative couples (p=0.0001), and when CR was achieved before BMT (p=0.0022). These results suggest that all efforts in this field should be directed on lowering the transplant related mortality for non geno-identical transplants and the relapse rate in geno-identical transplants.

Response at three months is a good predictive factor for newly diagnosed chronic myeloid leukemia patients treated by recombinant interferon-alpha

In a single institution, we have used recombinant interferon- (IFN-) to treat 116 newly diagnosed Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) patients and analyzed the predictive factors for response and survival. The patients whose median age was 50.3 years (range, 9 to 70) were administered IFN- (5 million units/m2/d) subcutaneously. The IFN- dose was subsequently adjusted to maintain the white blood cell and platelet counts between 1.5 and 5 x 10(9)/L, 50 and 100 x 10(9)/L, respectively. At diagnosis, the Sokal score was used to classify the patients into three groups: low (n = 57), intermediate (n = 42), and high risk (n = 16). A complete hematological response (CHR) was achieved in 93 cases (80.2%). Of the 116 patients, 113 were available for cytogenetic evaluation. Fifty patients (43%) achieved a major cytogenetic response (MCR) (=65% marrow Ph- cells), 37 of them having a complete cytogenetic response (CCR). The estimated 5-year survival of the 116 patients was 68% +/- 11% (95% confidence interval [CI]) with a median follow-up of 42 months (range, 3 to 114) and 85% +/- 11% (95% CI) with a median follow-up of 30.9 (range, 3 to 111) when patients were censored at the time of transplantation. Event-free survival at 5 years (adding death and transplant as event) was 46% +/- 11% (95% CI). Using proportional hazards regression to study time-dependent variables, we confirmed that the most significant factor associated with survival was the cytogenetic response (MCR or CCR) (P <.0001). This factor was independent compared with the Sokal score and baseline variables used to calculate the Sokal score. Moreover, using either univariate or multivariate analysis, the achievement of CHR within 3 months was strongly correlated with MCR (P <.0001). Minimum cytogenetic response (mCR, ie, at least 5% of Ph- metaphases) at 3 months was also a significant predictive factor for MCR (P <.0001). These results show that IFN- can induce a high rate of hematological and cytogenetic response when administered in doses leading to myelosuppression. Factors such as the achievement of CHR and mCR within 3 months could be useful to identify early those patients who will not respond to IFN- and who need alternative treatments such as stem cell transplantation.

Factors influencing haemopoietic recovery following chemotherapy-mobilised autologous peripheral blood progenitor cell transplantation for haematological malignancies: a retrospective analysis of a 10-year single institution experience

We retrospectively analysed the factors that influenced rate of haemopoietic recovery (HR) in 243 patients after transplantation with chemotherapy-mobilised autologous peripheral blood progenitor cells (PBPC). Approximately half the patients also received haemopoietic growth factors (HGF) for mobilisation. Conditioning for transplantation was with either chemotherapy alone or chemotherapy plus total body irradiation (TBI). Median time to recovery of granulocytes > or = 0.5 x 10(9)/l was 13 days (range 7-93 days) and of platelets > or = 50 x 10(9)/l 14 days (7-440). Speed of HR was greater, both for neutrophils and platelets for patients who received more rather than less CFU-GM than our median value of 18.9 x 10(4)/kg (P < 0.0001 in both instances) and more rather than less CD34-positive cells than our median value of 8.8 x 10(6)/kg (P < 0.0001 and P < 0.0005, respectively). For granulocyte recovery, in the multivariate analysis the dose of infused CFU-GM (P = 0.05) and the use of HGF for both mobilisation and post-transplantation (P < 0.0014) were significant positive factors. For platelet recovery in the multivariate analysis the dose of infused CFU-GM (P < 0.0016) was a positive factor. The use of busulphan and of TBI were significant adverse factors for rate of platelet recovery (P = 0.005 and 0.0004, respectively). When compared with non-HGF-mobilised PBPC, HGF-mobilised PBPC reduced the number of days of hospitalisation (28 vs 24, P = 0.0001) and of treatment with intravenous antibiotics (15 vs 11, P = 0.0004). These findings emphasise the importance of cell dose in accelerating haemopoietic recovery after autologous blood stem cell transplantation.

High response rate using recombinant interferon-alpha in patients with newly diagnosed chronic myeloid leukemia

To improve the management of chronic myeloid leukemia (CML) in a single center, we have used interferon-alpha (IFN-alpha) to treat newly diagnosed Ph-positive CML patients and investigated the factors predictive of a major cytogenetic response. Eighty-one patients with a median age of 50.5 y (17-70) were given IFN-alpha (5 x 10(6)/sqm/day, s.c.). The median interval between diagnosis and IFN-alpha was 45 days (0-160). IFN-alpha doses were adjusted to maintain the white blood cell (WBC) count between 1.5 and 5 x 10(9)/l and the platelet count between 50 and 100 x 10(9)/l. At diagnosis, Sokal's criteria were used to classify patients into three groups: low (n = 39), intermediate (n = 32) and high risk (n = 10). A complete hematological response (CHR) was achieved in 66 cases (81.5%). Cytogenetic response was evaluated in these 66 responders. Thirty-six patients (44.4%) achieved a major cytogenetic response (MCR) (> or = 65% Ph-negative cells), 31 of them having a complete cytogenetic response. The 5-y transformation-free survival (TFS) of the 81 patients was 77 +/- 14% (95% CI) and was statistically influenced by the CHR rate at three months (p = 0.008) and the achievement of MCR or CCR (p < 0.0009 and p < 0.0005, respectively). Moreover, we found that the MCR or CCR were significantly influenced by the obtaining of CHR at three months (p < 0.001 and p < 0.0001, respectively). These results show that IFN-alpha can induce high rates of hematological and cytogenetic responses when administered in doses leading to myelosuppression. The achievement of CHR within three months could be useful to identify early those patients who will not respond to IFN-alpha and who need alternative treatments such as allogeneic or autologous stem cell transplantation.

Autografting in chronic myeloid leukemia: an overview

Autografting could become a promising treatment for patients with chronic myeloid leukemia (CML) who cannot undergo allogeneic bone marrow transplantation or failed to respond to recombinant alpha-interferon (IFN). In this review, we analyze the results which have been published for patients transplanted in chronic phase and which suggest that autografting could prolong survival, at least in some patients. We also discuss the different methods of purging whose clinical efficacy remains to be assessed.

A prospective randomized trial of idarubicin vs daunorubicin in combination chemotherapy for acute myelogenous leukemia of the age group 55 to 75

A prospective randomized study was conducted comparing the efficacy and toxicity of two anthracyclines for the treatment of patients with acute myeloid leukemia (AML) between 55 and 75 years. A total of 220 patients were randomized to receive as induction chemotherapy cytosine arabinoside (Ara-C: 100 mg/m2/day; continuous infusion for 7 days) combined with either daunorubicin (DNR: 50 mg/m2/day, i.v. bolus for 3 days) (n=108) or idarubicin (IDA: 8 mg/m2/day, i.v. bolus for 5 days) (n=112). The complete remission (CR) rate was similar (P=0.296) after IDA (76/112; 68%) and DNR (66/108; 61%) (P=0.3). For patients aged 55-65, the CR rate was significantly higher after IDA (39/47; 83%) than after DNR (29/50; 58%) (P=0.007). Persistent leukemia was more frequent after DNR (26/108) than after IDA (13/112; P=0.015). Hematological and extra-hematological toxicities were similar. The CR patients were given a consolidation course of chemotherapy with Ara-C: 50 mg/m2/12 h, subcutaneously for 5 days, combined with either DNR:30 mg m2/day, i.v. bolus for 3 days or IDA:8 mg/m2/day i.v. bolus for 3 days according to the initial randomization, and then received a continuous maintenance treatment for 2 years. The survival and disease-free survival (DFS) were similar in both groups; there was no difference in the risk of relapse. However, there was a trend for a longer event-free survival (EFS) in the IDA group than for the DNR patients (P=0.07). Our results seem to indicate that IDA is probably more efficient than DNR for AML patients between 55 and 75 years, and confirm the data published in other studies comparing prospectively IDA and DNR in adults.

Response to recombinant interferon alpha in patients with chronic myelogenous leukemia in a single center: results and analysis of predictive factors

To improve the management of chronic myeloid leukemia (CML) in a single center, we used interferon alpha (IFN alpha) to treat newly diagnosed CML patients and investigated the factors predictive of a major cytogenetic response. Fifty-two patients (pts) with a median age of 51.5 years (16-68), were given interferon alpha (IFN alpha) (5 millions/m2/day, subcutaneously). The median interval between diagnosis and IFN alpha was 41.5 days (0-160). The doses of INF alpha were adjusted to maintain the white blood cell (WBC) count between 1.5 and 5 x 10(9)/l and the platelet count between 50 and 100 x 10(9)/l. At diagnosis, Sokal's criteria were used to classify patients into three groups: low (n = 24), intermediate (n = 19) and high risk (n = 9). A complete hematological response (CHR) was achieved in 42 cases (80.7%). A partial response was present in nine; only one patient did not respond. By multivariate logistic regression analysis, only the age at diagnosis was found to influence the CHR rate (P = 0.06). Cytogenetic response was evaluated in 46 responder patients. Twenty-three patients achieved a major cytogenetic response (MCR) which was either partial ( > or = 65% pH negative cells) (n = 3) or complete (CCR) (n = 20). By univariate analysis, two disease-related variables were found to influence the MCR rate in 40 evaluable CHR patients: spleen size at diagnosis and peripheral blood blast percentage. However, using either univariate or multivariate analysis, the most significant factor was the achievement of CHR within 3 months (P < 0.0004 and P < 0.0002, respectively). These results show that IFN alpha can induce high rates of hematological and cytogenetic responses when administered in doses leading to myelosuppression. The achievement of CHR within 3 months could be useful to identify early, those patients who will not respond to IFN alpha and who need alternative treatments such as allogeneic or autologous stem cell transplantation.

Autologous blood progenitor cell transplantation in high-risk multiple myeloma

The aim of the study was to evaluate the feasibility and the efficacy of high-dose chemoradiotherapy followed by autologous hematopoietic stem cell support with peripheral blood progenitor cells (PBPC) harvested after high-dose cyclophosphamide (HDCYC) treatment in patients with high-risk multiple myeloma (MM). Inclusion criteria were: age less than 65 years and high-risk MM defined as stage II MM, stage III MM, refractory or relapsed MM. The design of the study was: 1) HDCYC +/- hematopoietic growth factors followed by PBPC collection, and 2) high-dose melphalan combined with total body irradiation (or busulfan for previously irradiated patients) followed by PBPC reinfusion (ABPCT). All 60 patients completed the procedure except two who died from infection after HDCYC and another of acute cardiac failure after reinfusion of PBPC. Out of the 60 evaluable patients, three failed to respond while the other 57 achieved either a partial (n = 33) or complete (n = 24) response. Thirty-one patients progressed or relapsed after a median duration of response of 15 months (range: 3-43). The median follow-up for the other 26 responder patients was 24 months (range: 2-66). Twenty-one patients died, 18 of MM (2 after failure, 16 after relapse) and three responders of lung cancer (n = 1) and infection (n = 2). In conclusion, this study shows that this therapeutic approach is feasible and efficient.

Daunorubicin (DNR) accumulation in fresh leukemic cells: correlation with clinical and biological features

The DNR accumulation (DNR Acc) and the verapamil (VRP) index (percent increase of VRP on DNR accumulation) was studied by using flow cytometry. Fresh leukemic mononuclear bone marrow blasts from 80 unselected ANLL patients' samples were incubated with DNR in the presence or absence of VRP. The DNR accumulation was determined by flow cytometry. The median DNR Acc was 28 (range: 4-101) and the median VRP index was 4% (range 0-53). VRP significantly enhanced DNR Acc in 42 of the ANLL samples (52.5%). DNR Acc or VRP index were not influenced by age, sex, or WBC counts. Only the FAB subclassification and the blast immunophenotyping were found to influence the parameters studied here. The lowest DNR Acc was found in M0 and M6 blast cells (15 range 0-46 and 10.5 range 8-13 respectively). M4 and M5 ANLL samples accumulated significantly more DNR than M0 and M6 blast cells. The VRP index was significantly higher in M0 compared with M1 and M2 samples, as well as in M4 compared with M1 samples. A slightly positive correlation was found between the percentage of CD34-positive cells in the CD34-positive samples and DNR Acc. In this study, DNR Acc and the VRP index were not significantly correlated with the response to chemotherapy or survival. In conclusion, this study shows that ANLL leukemic cells differ in anthracyclin accumulation and response to VRP in vitro.

Regimen-related toxicity in patients undergoing BMT with total body irradiation using a sweeping beam technique

In our institution, total body irradiation (TBI) is performed by means of a sweeping beam technique. Toxicity of the procedure was evaluated according to the only grading system designed for high dose chemoradiotherapy. One hundred patients undergoing TBI and conditioned with a standard cyclophosphamide regimen before BMT were evaluated. Regimen-related toxicity was graded according to the Seattle transplantation toxicity system, from 0 to IV (fatal toxicity), in eight organs on days 0, 7, 14, 28 and 100 for lungs. Eighteen patients did not develop any toxicity. Grades III, IV toxicities were uncommon (9%) and were not influenced by dose of TBI, GVHD prophylaxis, disease status and allogenicity although no grade IV toxicity was observed among autologous marrow recipients. However, grade II toxicity was more common in patients receiving allogeneic vs autologous grafts (p < 0.01) because of increased mucosal (p = 0.002) and liver (p = 0.12) toxicities. Renal toxicity was unevaluable. When cumulative toxicity was equal or higher than 4, day 100 survival was worse (p = 0.05). These data confirm the safety of our TBI procedure and the validity of the grading system except for renal toxicity. We suggest that a more aggressive conditioning regimen may be tolerated by patients receiving autologous grafts.

Autologous blood stem cell transplantation for chronic granulocytic leukaemia in transformation: a report of 47 cases

Forty-seven patients with chromosome Philadelphia-positive (Ph1) chronic granulocytic leukaemia (CGL) in transformation underwent autologous transplantation of peripheral blood stem cells (ABSCT) collected at the original diagnosis before any treatment. They were treated with three consecutive strategies: single transplant (group I = 17 patients), double transplant (group II = 13 patients), double transplant followed by recombinant alpha interferon (group III = 17 patients). Forty-three patients were restored to a second chronic phase with a cytogenetic conversion (more than 10% Ph1-negative marrow metaphases) occurring in 14 of the 29 evaluable patients. Most patients had a recurrent transformation occurring 2-43 months after ABSCT and finally eight patients are still alive in second chronic phase 4-49 months after ABSCT (median = 24 months). The actuarial median duration of second chronic phase was 3 months, 10 months and 18 months for group I, group II and group III patients (P less than 0.0001). The encouraging results observed for group III patients prompt us to propose ABSCT for patients in chronic phase with initial prognostic factors, suggesting that recombinant alpha interferon will not be effective if administered as front-line therapy.