Multicenter prospective study of interferon-alpha and conventional chemotherapy versus bone marrow transplantation for newly diagnosed patients with chronic myelogenous leukemia. Kouseisho Leukemia Study Group

We compared interferon-alpha (IFN-alpha therapy with bone marrow transplantation (BMT) after initial conventional chemotherapy in patients with chronic myelogenous leukemia (CML) in a multicenter prospective study. Ninety patients with Philadelphia chromosome-positive CML in chronic phase were enrolled between 1991 and 1994. Sixty-six of 89 evaluable patients received IFN-alpha after conventional chemotherapy with hydroxyurea or busulfan (IFN-alpha group). Twenty-three patients received allogeneic BMT (BMT group). Fifteen of them received transplants from HLA-identical family donors and 8 from HLA-matched unrelated donors. Forty-seven of 66 patients (71%) in the IFN-alpha group and 17 of 23 patients (74%) in the BMT group achieved complete hematologic response, and 12% in the IFN-alpha group and 13% in the BMT group achieved partial hematologic response. Complete cytogenetic response was induced in 5 (8%), partial cytogenetic response in 8 (12%), and minor cytogenetic response in 12 (18%) in the IFN-alpha group. At a median follow-up of 54 months (range, 30-76 months), in the IFN-alpha group, the predicted 6-year survival rate was 54.5% and the predicted 6-year rate of those remaining in chronic phase was 45.7%. Compared with patients with no cytogenetic response, the patients with some cytogenetic response after IFN-alpha treatment had significantly superior survival and duration of the chronic phase even after correction for the time to response using landmark analysis (P < .05). In the BMT group, the predicted 5-year survival rate was 93.3% for family-donor BMT and 21.9% for unrelated-donor BMT Acute graft-versus-host disease of grade III or IV was observed in 1 of 15 patients who received family-donor BMT and 3 of 8 patients who received unrelated donor BMT. Prior treatment with conventional cytotoxic drugs induced early hematologic response and did not reduce the effect of IFN-alpha on CML. Unrelated-donor transplantation should be offered to some patients according to patient age, HLA-matching status, time from diagnosis to BMT, and risk factors.     

Outcome for patients who relapse after allogeneic bone marrow transplantation for chronic myeloid leukemia. Chronic Leukemia Working Party. European Bone Marrow Transplantation Group

We studied the clinical course of 130 chronic myeloid leukemia (CML) patients (89 males and 41 females) in the European Bone Marrow Transplantation Group (EBMT) registry who received transplants before January 1, 1988 and who subsequently had evidence of recurrent leukemia. All patients had received a pretransplant conditioning regimen including total body irradiation (TBI). The first evidence of relapse was cytogenetic only in 74 (57%) patients and hematologic in 56 (43%). The overall actuarial survival from relapse was 36% at 6 years, with a significantly higher proportion of survivors among female patients (53% v 30%; P < .002). In univariate analysis, the 6-year probability of survival was 52% for patients with cytogenetic relapse and 30% for patients relapsing in chronic phase (CP), while no patient who relapsed in advanced phase (AP or BC) survived more than 3.5 years from relapse (P < .0001). The actuarial survival of patients relapsing before 6 months, between 6 and 12 months, and later than 12 months after transplant was 27%, 26%, and 45%, respectively (P < .002). Among patients with cytogenetic relapse, partial or complete disappearance of Ph-positive cells occurred in 40% of untreated patients and in 42% of those treated with interferon (IFN). However, IFN therapy significantly delayed progression toward hematologic disease. Cytogenetic responses were observed in 25% of patients who received IFN for relapse into CP, while only one minor cytogenetic response was reported in patients on conventional chemotherapy. For patients presenting with cytogenetic relapse as well as for those in hematologic relapse, IFN therapy significantly improved the 2-year probability of survival. However, long-term survival for IFN-treated patients in either group was not different from long-term survival in comparable patients not receiving IFN therapy. Twenty-nine patients of this series underwent a second bone marrow transplant (BMT) and the projected survival at 4 years after the second transplant is 28%. In multivariate Cox regression analysis, four factors remained significantly associated with survival: disease phase at relapse (P < .0001), duration of time interval from BMT to relapse (P = .0001), interferon therapy at relapse (P = .0024), and patient sex (P = .0032). This retrospective study provides evidence that some patients who relapse after BMT may benefit from treatment with IFN; a second BMT may offer the chance of cure. Data from this analysis may be useful in designing future prospective trials on posttransplant CML relapse.     

Cytogenetic events after bone marrow transplantation for chronic myeloid leukemia in chronic phase

Forty-eight patients treated by allogeneic bone marrow transplantation (BMT) for Philadelphia (Ph) chromosome-positive chronic myeloid leukemia in chronic phase had serial cytogenetic studies of marrow performed at intervals after transplant. Twenty patients received marrow cells from donors of opposite sex. Ph+ marrow metaphases were identified in 24 of 48 (50%) of patients after BMT; they were first seen early (within 1 year) in 16 cases and late (greater than 1 year after BMT) in eight cases. Ph-positivity after BMT occurred more commonly in recipients of T-depleted than nondepleted marrow (19 of 28 v 5 of 20). In 4 cases the Ph+ metaphases were found only transiently after BMT; in 11 cases the Ph+ metaphases have persisted but hematologic relapse has not ensued; in 9 cases the finding of Ph+ metaphases coincided with or preceded hematologic relapse. Chromosomes in cells of donor origin had morphological abnormalities in two cases. No relapses were identified in cells of donor origin. Our data suggest that the relationship between cells of recipient and donor origin is complex: cure of leukemia may depend on factors that operate for some months or years after BMT.     

Use of alpha interferon for the treatment of relapse of chronic myelogenous leukemia in chronic phase after allogeneic bone marrow transplantation.

Eighteen patients with relapse of chronic myelogenous leukemia (CML) after allogeneic bone marrow transplantation (BMT) were treated with recombinant human alpha 2a interferon (IFN). Relapse was defined as greater than 90% metaphases containing the Philadelphia chromosome (Ph) and hematologic abnormalities consistent with chronic-phase (CP) CML. There were 11 males and seven females, with a median age of 38 years (range, 3 to 55). Three patients relapsed after second BMT. Only one patient had received T-cell-depleted marrow initially. The initial IFN dose of 3 x 10(6) U/m2/d was escalated to the maximum tolerated dose or to a maximum of 6 x 10(6) U/m2/d. IFN controlled the white blood cell (WBC) counts in 14 of 16 patients who had abnormal counts, and in all six patients with an elevated platelet count. Six patients (33%) have had a complete disappearance of the Ph and two have had a partial response (less than 35% Ph+ metaphases). One patient has a decrease in Ph+ metaphases after 9 months of IFN. Five patients had no significant cytogenetic response after 9 to 12 months, and four developed clinical accelerated phase or blast crisis after 3 to 6 months on therapy. Of four patients with a sex marker, the Ph- population was of donor origin in three and of host origin in one. Clonal cytogenetic abnormalities other than Ph were present in 13 patients and did not predict for lack of response to IFN. IFN is effective in suppressing the Ph clone in some patients who relapse with CML after allogeneic BMT and controls the blood counts in the majority.     

Interferon alpha for chronic myeloid leukemia relapsing after allogeneic bone marrow transplantation

Interferon alpha (IFN alpha) induces cytogenetic responses in patients with chronic myeloid leukemia (CML) who relapse after allogeneic bone marrow transplantation (BMT). The purpose of this study was to analyze the therapeutic role of IFN alpha in this setting. The experience of a single institution and the published results on this topic were evaluated. We have included patients who received IFN alpha as a single agent, excluding those patients who received previous or simultaneous donor leukocyte infusions. The outcomes of 11 patients treated in our center and those of 108 previously reported patients have been analyzed. Five out of 11 patients treated in our institution obtained a complete cytogenetic response (CGR). Two patients continue in complete cytogenetic response 3.5 and 8.2 years later, and the qualitative RT-PCR is negative for bcr-abl RNA. The CGR has been transient in one patient, and follow-up is short in the other two. Secondary effects have been acceptable, with myelosuppression as the main toxic effect. Graft-versus-host disease did not occur. The literature review identified 108 patients treated with IFN alpha as sole therapy for relapsed CML. Cytogenetic response and CGR seem to be better in patients with cytogenetic relapse, as compared to patients with hematologic relapse (61% vs. 45% and 45% vs. 28%, respectively). Several patients remained in CGR for more than 5 years. This overview also suggests that CGR is more frequent when IFN alpha is used in patients relapsing after non T-depleted BMT. IFN alpha induces complete cytogenetic response in nearly half of the patients with CML who relapse after allogeneic BMT, with acceptable toxicity. We believe that these results using IFN alpha as a front-line therapy for CML relapsing after BMT warrant a randomized comparison with donor lymphocyte infusions.     

Clinical significance of minimal residual disease, as assessed by different techniques, after stem cell transplantation for chronic lymphocytic leukemia

We analyzed minimal residual disease (MRD) by consensus polymerase chain reaction (PCR), quantitative PCR (qPCR), and flow cytometry in 40 patients with chronic lymphocytic leukemia (CLL) who underwent stem cell transplantation; 97.4%, 89%, and 100% of the patients could be studied by consensus PCR, qPCR, and flow cytometry, respectively. Overall, 164 of 248 samples were negative for MRD by consensus PCR. Among those, CLL cells were detected by qPCR and by flow cytometry in 77 (47%) and 39 (23%) of the 164 samples, respectively. All 84 samples positive on PCR had detectable CLL cells by qPCR and flow cytometry. A good correlation was seen between MRD levels by flow cytometry and by qPCR (n = 254; r = 0.826; P < .001). Fifteen of 25 patients receiving autografts suffered a relapse, with increasing levels of MRD being observed before relapse in all of them. MRD detection within the first 6 months after autologous transplantation identified patients with a high relapse risk. In contrast, in allografted patients (n = 15) MRD did not correlate with outcome. In conclusion, quantitative methods to assess MRD (flow cytometry and qPCR) are more accurate than consensus PCR to predict clinical evolution. These results might be useful to investigate treatments aimed at preventing relapse in patients with CLL who have received an autograft.     

Relapse of chronic myeloid leukemia after allogeneic bone marrow transplant: the case for giving donor leukocyte transfusions before the onset of hematologic relapse

Fourteen patients with chronic myeloid leukemia (CML) relapsing after allogeneic bone marrow transplant (BMT) were treated with leukocyte transfusions from the original marrow donor (sibling, n = 9; volunteer unrelated, n = 5). The relapse was defined at the molecular level in two cases, cytogenetically in five cases and hematologically in seven cases. Ten patients responded, seven of seven patients with cytogenetic/molecular relapse compared with three of seven with hematologic relapse (P < .03). All five recipients of cells from unrelated donors responded. Eight of the 10 responders have achieved polymerase chain reaction-negative status and this persisted in three patients for more than 2 years; no responder has shown sign of relapse. Reversible marrow aplasia occurred in two patients, both treated in hematologic relapse. Severe graft-versus-host disease occurred in four patients and was fatal in one. We confirm previous reports that donor leukocyte transfusions are effective in the management of CML in relapse after BMT. In this series, therapeutic intervention before the onset of hematologic relapse was associated with an increased likelihood of response and no marrow aplasia.     

Allogeneic cell therapy with donor peripheral blood cells and recombinant human interleukin-2 to treat leukemia relapse after allogeneic bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) is the only effective treatment for hematologic malignancies resistant to conventional chemotherapy. Until recently, no cure existed for patients who relapsed post-BMT. We present our long-term observations on remission induction, after relapse post-BMT, by allogeneic cell therapy (allo-CT) and the feasibility of remission induction in allo-CT-resistant patients by activation of antileukemia effector cells with recombinant human interleukin-2 (rhIL-2) in vitro and in vivo. The longest observation of successful allo-CT (event-free survival, greater than 8 years) was made in a patient with resistant pre-B lymphoblastic leukemia who received infusions with graded increments of donor (female) peripheral blood lymphocytes (PBL) as soon as bulky hematologic and extramedullary relapse was noticed early post-BMT. The patient is currently without evidence of residual host (male) cells as determined by polymerase chain reaction (PCR). Of 17 patients with acute and chronic leukemia in relapse after BMT, 10 were reinduced into complete remission. Four patients with cytogenetic relapse responded to allo-CT alone, while five of six patients with overt hematologic relapse responded only after additional activation of donor with rhIL-2. Allo-CT can, therefore, successfully reverse chemoradiotherapy-resistant relapse of both acute and chronic leukemia. Moreover, in patients resistant to donor lymphocyte infusion, remission can be accomplished by additionally activating donor PBL in vitro and/or in vivo with rhIL-2. Based on our observations, after BMT, allo-CT should be considered the treatment of choice for patients with hematologic malignancies resistant to conventional anticancer modalities. Allogeneic activated cell therapy (allo ACT) should be considered for patients with tumor cells resistant to allo-CT. Although allo-CT, followed if indicated by allo-ACT, can be effective for patients with overt hematologic relapse, reversal of persistent minimal residual disease or documented molecular/cytogenetic relapse early after BMT may also be considered as a possible indication for allo-CT.     

Growth in children after bone marrow transplantation for acute leukemia

We evaluated the growth of children with acute leukemia who received a bone marrow transplant (BMT) after preparation with hyperfractionated total body irradiation (TBI). Seventy-two patients (27 female and 45 male patients) with acute lymphoblastic leukemia (ALL; n = 39) or acute myelogenous leukemia (AML; n = 33) who were less than 14 years of age at BMT were studied. Before BMT all had received multiagent chemotherapy and 31 had received cranial irradiation (RT). Preparation for BMT included total body irradiation (1,375 cGy [n = 37] or 1,500 cGy [n = 35]). Heights, expressed as standard deviation scores (SDS), were studied up to 4 years post-BMT. The estimated height SDS for the entire group at the time of BMT was -0.28 +/- 0.05 and decreased to - 1.11 +/- 0.22 at 4 years post-BMT (P < .0001). Using a growth curve model to compare covariate groups over the period of study, we found that the loss in height SDS was most significant in those patients who received cranial RT before BMT (P = .005). The estimated height SDS for patients treated with cranial RT went from -0.52 +/- 0.20 at transplantation to -1.83 +/- 0.23 4 years later. In contrast, patients who did not receive cranial RT before BMT showed a smaller decrease in height SDS over the 4-year observation period, ie, -0.11 +/- 0.20 decreasing to -0.73 +/- 0.21. Similarly, patients with a diagnosis of ALL had a greater loss of height SDS than those with AML (P = .033). Fifteen of 18 patients tested were found to be growth hormone (GH) deficient; 9 patients were treated with GH and all showed an improvement in growth velocity (P < .0001). We conclude that (1) children with acute leukemia who have received cranial RT and subsequently undergo BMT, primarily those with ALL, are at high risk for growth failure and GH deficiency, and (2) that fractionation of TBI may have a relative sparing effect on growth.     

Mixed hematopoietic chimerism following bone marrow transplantation for hematologic malignancies

Twenty-nine of 172 patients (17%) who received an allogeneic bone marrow transplant (BMT) from histocompatible sibling donors for hematologic malignancies were mixed hematopoietic chimeras; ie, they had a mixture of donor and host hematopoietic or lymphohematopoietic cells at greater than or equal to 14 days after transplantation. Twenty- four of the 29 mixed chimeras (83%) have remained in continuous complete remission for up to 116 months (greater than 9 years) following BMT. Four of the 29 patients (14%) have had recurrent leukemia, and 7 of the 29 (24%) have had moderate or severe graft-v- host disease (GVHD). Twelve of these 29 patients have persisted as stable mixed chimeras for greater than or equal to 2 years after BMT, whereas other patients converted to all donor-type hematopoiesis. The incidence of mixed chimerism was independent of the pretransplant regimen, the donor or recipient age (less than 20 v greater than 20 years), remission status (first complete remission of acute leukemia and first chronic phase of chronic myelocytic leukemia v later stages of disease), and type of leukemia. Our data indicate that mixed hematopoietic chimerism is not rare after BMT for hematologic malignancies and that its presence is compatible with long-term disease- free survival. Prospective studies of mixed chimerism after BMT are warranted to achieve better understanding of its biologic importance.     

Minimal residual disease is more common in patients who have mixed T- cell chimerism after bone marrow transplantation for chronic myelogenous leukemia

Determining both lymphoid chimerism and the presence of minimal residual disease after allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia (CML) could be helpful to the understanding of the biology of leukemic relapse in this disease. We prospectively investigated 32 patients with CML post-BMT by assessing T- cell chimerism and minimal residual disease using sensitive polymerase chain reaction (PCR) methodologies. Patients were studied between 1 and 24 months post-BMT. Thirty patients received a T-cell-depleted marrow grafts and 2 received unmanipulated marrow. All but 1 patient were conditioned with total body irradiation (TBI)+thiotepa+cyclophosphamide (Cy). The other patient received TBI+Cy as conditioning. The T cells were exclusively of donor origin in 12 of 16 patients who were tested at 1 month post-BMT, but were mixed chimeric in 11 of these patients by > or = 3 months. Once mixed T-cell chimerism was documented, no patient returned to having all donor T-cells. At a median follow-up of 12 months, minimal residual disease was present in 18 of 22 patients with mixed T-cell chimerism and in 3 of 10 patients with full donor chimerism. The actuarial molecular relapse rate at 24 months for the two groups is 91% and 33%, respectively (P < .02). The finding of BCR- ABL mRNA within the first 6 months of transplant or on two consecutive assays was highly predictive of subsequent cytogenetic or hematologic relapse (P = .032 and P < .02, respectively). Ten patients, 9 with mixed T-cell chimerism, have relapsed (4 clinical, 6 cytogenetic) at a median of 12 months post-BMT. These data suggest that mixed T-cell chimerism may be a marker for abrogation of graft-versus-leukemia activity that is thought to be pivotal in eradicating minimal residual disease after BMT for CML.     

Allogeneic or autologous bone marrow transplantation for acute lymphoblastic leukemia in first complete remission

Forty-seven patients with high risk acute lymphoblastic leukemia (ALL) received an allogeneic (allo) or autologous (auto) bone marrow transplant (BMT). Patients in both groups were comparable in terms of age, initial presentation of ALL and induction chemotherapy. Allo patients were transplanted earlier (median 3 months after CR) than auto patients (median 6.5 months after CR). Auto patients received more consolidation chemotherapy before BMT. All patients received total body irradiation 2.2 Gy/day x 5 days after cyclophosphamide 60 mg/kg x 2 (18 allo and five auto) or melphalan 140 mg/m2 (seven allo and 17 auto). Prevention of graft-versus-host disease (GVHD) was by conventional immunosuppression in 17 patients and T cell depletion in eight. Seven patients (28%) developed moderate to severe acute GVHD. Auto marrow was treated in vitro in each case. Seven patients died in CR from BMT complications (five allo and two auto). The probability of relapse was 9% for patients receiving allo BMT and 52% for patients receiving auto BMT (p less than 0.01). The disease-free survival was 71% for allo BMT and 40% for auto BMT (p = NS). Early BMT is an effective form of consolidation for high risk patients with ALL in first CR. An allogeneic anti-leukemia effect was demonstrated in this study.     

CD8-depleted donor lymphocyte infusion as treatment for relapsed chronic myelogenous leukemia after allogeneic bone marrow transplantation

Donor lymphocyte infusions can reinduce complete remission in the majority of patients with chronic myelogenous leukemia (CML) who relapse into chronic phase after allogeneic bone marrow transplantation (BMT). Such infusions are associated with a high incidence of graft- versus-host disease (GVHD) and marrow aplasia. BMT using selective depletion of CD8+ lymphocytes from donor cells reduces the incidence of GVHD without an increase in leukemia relapse. We hypothesized that infusion of CD8-depleted donor peripheral blood lymphocytes could also reinduce complete remissions with a lesser potential to produce symptomatic GVHD in patients with CML who relapsed after allogeneic BMT. Ten patients with Ph(+) CML who relapsed a median of 353 days after BMT (range, 82 to 1,096 days) received donor lymphocyte infusions depleted of CD8+ cells. Nine patients received a single infusion and 1 received two infusions. Four patients were treated while in chronic phase with clonal evolution, 2 during accelerated phase, 3 during blast crisis, and 1 in a cytogenetic relapse. A mean of 0.9 +/- 0.3 x 10(8) mononuclear cells/kg were infused, containing 0.6 +/- 0.4 x 10(6) CD3+CD8+ cells/kg. Six patients achieved hematologic and cytogenetic remission at 4, 8, 11, 15, 39, and 54 weeks after lymphocyte infusion. Two patients developed > or = grade II acute GVHD, and 1 patient developed mild chronic GVHD. We conclude that donor lymphocyte infusions depleted of CD8+ cells can induce remissions with a low rate of severe acute GVHD in patients with CML who relapse after allogeneic BMT, supporting the hypothesis that CD8+ lymphocytes are important effectors of GVHD, but may not be essential for the graft-versus- leukemia effect against this disease. Further controlled studies are required to confirm these preliminary observations.     

Autologous bone marrow transplantation in high-risk remission T-lineage acute lymphoblastic leukemia using immunotoxins plus 4-hydroperoxycyclophosphamide for marrow purging

Fourteen patients with high-risk T-lineage acute lymphoblastic leukemia (ALL) in complete remission underwent autologous bone marrow transplantation (BMT) in an attempt to eradicate their residual disease burden. A combined immunochemotherapy protocol using a cocktail of two immunotoxins directed against CD5/Tp67 and CD7/Tp41 T-lineage differentiation antigens in combination with the in vitro active cyclophosphamide congener 4-hydroperoxy-cyclophosphamide (4-HC) was used to purge autografts. Despite high dose pretransplant radiochemotherapy and effective purging of autografts, 9 of 14 patients relapsed at a median of 2.5 months (range, 1.2 to 16.8 months) post BMT. Two patients remain alive and disease free at 26 and 28 months post BMT. We used a novel quantitative minimal residual disease (MRD) detection assay, which combines fluorescence activated multiparameter flow cytometry and cell sorting with leukemic progenitor cell (LPC) assays, to analyze remission bone marrow (BM) samples from T-lineage ALL patients for the presence of residual LPCs. Notably, high numbers of residual LPC detected in remission BM before BMT constituted a poor prognostic indicator, providing the first evidence for the biologic significance and clinical value of in vitro T-lineage ALL LPC assays. The median value for the residual leukemia burden before BMT, was approximately 8.6 x 10(3) LPC/10(8) mononuclear cells (MNC) (approximately 0.0086% LPC). Patients with a residual leukemia burden less than this median value appeared to have a better outlook for remaining free of relapse after autologous BMT than patients with a greater leukemia burden (53 +/- 25% v 14 +/- 13%, P = .006, Mantel-Cox). By comparison, the log kill efficacy of purging, the remaining numbers of LPC in purged autografts, or the estimated numbers of reinfused LPC, did not correlate with the probability of disease-free survival (DFS). These results indicate that the primary reason for the recurrence of leukemia was inefficient pretransplant radiochemotherapy rather than inefficient purging of autografts.