Cyclophosphamide followed by fludarabine for untreated chronic lymphocytic leukemia: a phase II SWOG TRIAL 9706.

B-cell chronic lymphocytic leukemia (CLL) accounts for 95% of chronic leukemia cases and 25% of all leukemia. Despite the prevalence of CLL, progress in its treatment has been only modest over the past three decades. Based upon the ability of fludarabine to produce high-grade remissions especially among patients with low initial tumor mass, and the ability of alkylators to reduce tumor mass, we hypothesized that sequential administration of a limited number of cycles of intermediate-dose cyclophosphamide followed by fludarabine could result in a larger percentage of patients with complete remissions (CRs). In all, 27 of the 49 eligible patients achieved overall responses of CR, unconfirmed complete remission (UCR), or PR, for a total response rate of 55% (95% confidence interval (CI) 40-69%). Considering the confounding medical issues of this patient population with advanced aggressive disease, the regimen was generally well tolerated. This study demonstrates that high-dose cyclophosphamide followed by fludarabine was relatively well tolerated in this group of advanced CLL patients. The study's criterion for testing whether the regimen is sufficiently effective to warrant further investigation was met: 14 (32%) of the first 44 eligible patients achieved CR or UCR.

Biodistribution and dosimetry following infusion of antibodies labeled with large amounts of 131I.

Dosimetry and treatment planning for therapeutic infusions of radiolabeled antibodies are usually performed by extrapolation from the biodistribution of trace-labeled antibody. This extrapolation assumes that the biodistribution of high specific activity antibody will be similar to that seen with trace-labeled antibody. However, high doses of radiation result in rapid depletion of lymphoid and hematopoietic cells in lymph nodes, spleen, and marrow with replacement by blood and plasma. If radiolabeled antibody is cleared slowly from blood, this replacement may result in increased radionuclide concentrations in these tissues following infusions of antibody labeled with large amounts of radionuclide. To examine the influence of deposited radiation on the biodistribution of radiolabeled antibody, we treated mice with a constant amount of antibody that was labeled with varying amounts of 131I. Survival was determined in normal specific pathogen-free AKR/Cum mice (Thy1.2+) after infusion of anti-Thy1.1 antibody labeled with 10 to 6500 muCi of 131I, to determine an appropriate range of 131I doses for further study. The dose producing 50% lethality within 30 days following infusion of 131I-labeled antibody was 530 muCi 131I. Biodistribution, bone marrow histology, and dosimetry were subsequently determined after infusion of 500 micrograms of antibody labeled with 10, 250, 500, or 3500 muCi 131I. The amount of 131I did not influence uptake or retention of antibody in blood, liver, lung, or kidney. In contrast, infusion of antibody labeled with 250 to 3500 muCi of 131I led to a dose-related increase in the concentration of 131I in marrow, spleen, lymph node, and thymus. For example, at 96 h after infusion of antibody labeled with 500 or 3500 muCi 131I, concentrations in marrow were 3- to 4-fold higher than after infusion of trace-labeled antibody. The increase in marrow 131I concentrations was associated with depletion of cells and hemorrhage within the marrow space. As a result, estimated mean absorbed doses to marrow, lymph node, spleen, and thymus were 1.2 to 3.1 times higher than would have been predicted from the biodistribution of trace-labeled antibody. These results suggest that the biodistribution of trace-labeled antibody should be an accurate predictor of the behavior of high specific activity antibody in blood and solid organs such as liver and kidney. In contrast, radiation from antibody labeled with large amounts of radionuclide can result in an alteration of the concentration of radiolabeled antibody in rapidly responding tissues such as marrow.(ABSTRACT TRUNCATED AT 400 WORDS)

Localization of radiolabeled antimyeloid antibodies in a human acute leukemia xenograft tumor model.

Acute myeloid leukemia is an attractive disease to treat with radiolabeled antibodies because it is radiosensitive and antibody has ready access to the marrow cavity. In order to evaluate potentially useful radiolabeled antibodies against human acute myeloid leukemia, we have developed a nude mouse xenograft model using the human acute leukemia cell line, HEL. Mice with s.c. xenografts of HEL cells received infusions of radioiodinated anti-CD33 antibody. Examination of the biodistribution of the antibody showed that uptake in the s.c. tumor was maximal [16.9% injected dose (ID)/g at 1 h after infusion] following infusion of 1-10 micrograms of antibody and decreased following infusion of 100 micrograms (6.5% ID/g at 1 h) presumably as a result of saturation of antigen sites. The radiolabel was poorly retained in tumor (4.5-8.2% ID/g at 24 h after infusion). These results were consistent with in vitro studies demonstrating rapid internalization and catabolism of the anti-CD33 antibody. Uptake in tumor could be improved by using either a radiolabel that is retained intracellularly, 111In-DTPA (18.5% ID/g at 24 h), or by targeting a surface antigen that does not internalize upon antibody binding, CD45 (20.5% ID/g at 24 h). These results indicate that this model system will be useful in evaluating the interaction of radiolabeled antibodies with human acute myeloid leukemia cells in an in vivo setting.

Selective radiation of hematolymphoid tissue delivered by anti-CD45 antibody.

The ability to deliver radiation selectively to lymphohematopoietic tissues may have utility in conditions treated by myeloablative regimens followed by bone marrow transplantation. Since the CD45 antigen is the most broadly expressed of hematopoietic antigens, we examined the biodistribution of radiolabeled anti-CD45 monoclonal antibodies in normal mice. Trace 125I or 131I-labeled monoclonal antibodies 30G12 (rat IgG2a), 30F11 (rat IgG2b), and F(ab')2 fragments of 30F11 were injected i.v. at doses of 5 to 1000 micrograms. For both intact antibodies, a higher percentage of injected dose/g (% ID/g tissue) in blood was achieved with higher antibody doses. However, as the dose of antibody was increased, the % ID/g in the target organs of spleen, marrow, and lymph nodes decreased. At doses between 5 and 10-micrograms, % ID/g in these tissues exceeded that in lung, the normal organ with the highest concentration of radiolabel. In contrast, thymus was the only hematopoietic organ in which the % ID/g increased with increasing antibody dose, although at high dose the % ID/g was still far below that achieved in the other hematopoietic organs. Antibody 30F11 F(ab')2 fragments were cleared more quickly than intact antibody from blood and from both target and nontarget organs, although the relationship between increasing antibody dose and decreasing % ID/g in spleen, marrow, and lymph nodes was observed. The time-activity curves for each dose of antibody were used to calculate estimates of radiation absorbed dose to each organ. At the 10-micrograms dose of 30G12, the spleen was estimated to receive a radiation dose that was 13 times more than lung, the lymph nodes 3 to 4 times more, and the bone marrow 3 times more than lung. For each antibody fragment dose, the radiation absorbed dose per MBq 131I administered was lower because the residence times of the fragments were shorter than those of the intact antibody. Thus these estimates suggested that the best "therapeutic ratio" of radiation delivered to target organ as compared to lung was achieved with lower doses of intact antibody. We have demonstrated that radiolabeled anti-CD45 monoclonal antibodies can deliver radiation to lymphohematopoietic tissues with relative selectivity and that the relative uptake and retention in different hematolymphoid tissues change with increasing antibody dose.

High dose radiolabeled antibody therapy of lymphoma.

A trial has been initiated testing the effects of high dose radiolabeled monoclonal antibody administered in conjunction with marrow transplantation for treatment of lymphoma. This study is based on observations in mice demonstrating that radiolabeled antibody against a normal lymphocyte-associate antigen can induce regression of lymphoma masses. These preclinical studies also showed that large amounts of antibody are needed to achieve adequate biodistribution in vivo and that potentially curative doses of radionuclide induce substantial hematopoietic toxicity. Consequently, in patients with recurrent lymphoma, we are first evaluating the influence of dose on the biodistribution of a pan B-cell antibody, MB-1 (anti-CD37). In four patients, the biodistribution studies indicated that at the highest amount of antibody tested 131I-labeled antibody MB-1 (10 mg/kg) could deliver more radiation to tumor than to normal organs. These patients were treated with antibody MB-1 labeled with 250 to 482 mCi 131I estimated to deliver 380 to 1570 cGy to normal organs and 850 to 4260 cGy to tumor. Myelosuppression occurred in all patients and required infusion of cryopreserved marrow in one patient. Complete tumor regressions were observed in each patient. In three other patients with splenomegaly and/or large tumor burden, biodistribution studies indicated that 131I-labeled antibody could not deliver more radiation to tumor than to normal organs and these patients were not treated. Thus, tumor burden and spleen size may determine the feasibility of treatment with radiolabeled antibody. Treatment with this antibody labeled with high doses of 131I was well tolerated and may prove therapeutically useful. These studies are being continued to determine the maximal doses of radiation that can be tolerated by nonhematopoietic tissues after infusion of 131I-labeled antibody.

Comparative metabolism and retention of iodine-125, yttrium-90, and indium-111 radioimmunoconjugates by cancer cells.

Radiolabeled antibodies have produced encouraging remissions in patients with chemotherapy-resistant hematological malignancies; however, the selection of therapeutic radionuclides for clinical trials remains controversial. In this study, we compared the internalization, lysosomal targeting, metabolism, and cellular retention of radiolabeled murine and humanized monoclonal antibodies targeting the CD33 antigen (monoclonal antibodies mP67 and hP67, respectively) on myeloid leukemia cell lines (HEL and HL-60) and of anti-carcinoma antibodies (monoclonal antibodies hCTM01 and hA33) targeting breast cancer and colorectal carcinoma cell lines (MCF7 and Colo 205, respectively). Each antibody was labeled with 125I (by the IodoGen method) and with 111In and 90Y using macrocyclic chelation technology. Targeted tumor cells were analyzed for retention and metabolism of radioimmunoconjugates using cellular-radioimmunoassays, Percoll gradient fractionation of cell organelles, SDS-PAGE, and TLC of cell lysates and culture supernatants. Our results suggest that antibodies are routed to lysosomes after endocytosis, where they are proteolytically degraded. [125I]monoiodotyrosine is rapidly excreted from cells after lysosomal catabolism of antibodies radioiodinated by conventional methods, whereas small molecular weight 111In and 90Y catabolites remain trapped in lysosomes. As a consequence of the differential disposition of small molecular weight catabolites, 111In and 90Y conjugates displayed superior retention of radioactivity compared with 125I conjugates when tumor cells were targeted using rapidly internalizing antibody-antigen systems (e.g., hP67 with HEL cells and hCTM01 with MCF7 cells). When tumor cells were targeted using antibody-antigen systems exhibiting slow rates of endocytosis (e.g., hP67 on HL-60 cells and hA33 on Colo 205 cells), little differences in cellular retention of radioactivity was observed, regardless of whether 125I, 111In, or 90Y was used.

Pre- and post-transplant quantification of measurable ('minimal') residual disease via multiparameter flow cytometry in adult acute myeloid leukemia.

Measurable ('minimal') residual disease (MRD) before or after hematopoietic cell transplantation (HCT) identifies adults with AML at risk of poor outcomes. Here, we studied whether peri-transplant MRD dynamics can refine risk assessment. We analyzed 279 adults receiving myeloablative allogeneic HCT in first or second remission who survived at least 35 days and underwent 10-color multiparametric flow cytometry (MFC) analyses of marrow aspirates before and 28±7 days after transplantation. MFC-detectable MRD before (n=63) or after (n=16) transplantation identified patients with high relapse risk and poor survival. Forty-nine patients cleared MRD with HCT conditioning, whereas two patients developed new evidence of disease. The 214 MRD(neg)/MRD(neg) patients had excellent outcomes, whereas both MRD(neg)/MRD(pos) patients died within 100 days following transplantation. For patients with pre-HCT MRD, outcomes were poor regardless of post-HCT MRD status, although survival beyond 3 years was only observed among the 58 patients with decreasing but not the seven patients with increasing peri-HCT MRD levels. In multivariable models, pre-HCT but not post-HCT MRD was independently associated with overall survival and risk of relapse. These data indicate that MRD(pos) patients before transplantation have a high relapse risk regardless of whether or not they clear MFC-detectable disease with conditioning and should be considered for pre-emptive therapeutic strategies.

Review of the use of marrow transplantation in the treatment of non-Hodgkin's lymphoma.

High-dose chemoradiotherapy followed by marrow transplantation has become a widely used form of therapy for patients with acute leukemia. Because of the success of marrow transplantation in the treatment of this disease, there has been increased interest in the possible application of marrow transplantation to the treatment of other malignancies known to be sensitive to chemotherapy and radiotherapy. In this paper we review the rationale behind the application of marrow transplantation to the treatment of non-Hodgkin's lymphoma and the results that have been achieved to date.

Treatment of relapsed non-Hodgkin's lymphomas with dexamethasone, high-dose cytarabine, and cisplatin before marrow transplantation.

Combination chemotherapy is capable of curing many patients with newly diagnosed intermediate- and high-grade non-Hodgkin's lymphomas (NHL), but treatment of relapsed NHL remains problematic. Bone marrow transplantation (BMT) offers the best chance for disease-free survival, but interim chemotherapy is often necessary while awaiting BMT, especially for patients with bulky disease. We report here 39 patients (median age, 44 years) who failed primary therapy with doxorubicin-based regimens and subsequently were treated with one to six cycles of dexamethasone, 40 mg intravenous (IV) every day on days 1 to 4, cisplatin 100 mg/m2 by continuous infusion on day 1, and cytarabine 2 g/m2 IV every 12 hours x two doses on day 2 (DHAP) before the planned BMT. Histologies included 16 diffuse large-cell, six diffuse mixed, five diffuse small-cleaved, four lymphoblastic, and eight other. Twenty-eight patients had stage IV disease, 13 had B symptoms, and 20 had an elevated lactate dehydrogenase (LDH). Patients had been treated with a median of three previous chemotherapy regimens. Sixty-one percent of patients had high tumor burdens according to the MD Anderson criteria. Objective responses to DHAP were seen in 26 patients (67%) including nine complete responses (CRs) (23%) and 17 partial responses (PRs) (44%), and responses lasted a median of 7.5 months. Myelosuppression was the major toxicity, but there were no treatment-related deaths. To date, 17 patients have undergone subsequent BMT with a projected 3-year disease-free survival of 15%. We conclude that the DHAP regimen is effective short-term salvage therapy for relapsed NHL patients, but the long-term prognosis of multiply relapsed patients remains poor.

The detection of bone marrow involvement by lymphoma using magnetic resonance imaging.

We used magnetic resonance (MR) to image the bone marrow of 31 patients with lymphoma. Images were obtained of the femoral, pelvic, and vertebral marrow with a 0.15 tesla imaging system using a T1-weighted spin echo sequence (TR600/TE 40). With this pulse sequence, normal marrow produces a high intensity signal that reflects the presence of marrow fat (short T1 relaxation time). We previously reported MR imaging of patients with leukemia in relapse and found a diffusely and symmetrically decreased marrow signal intensity due to the replacement of normal marrow fat by cellular material with a long T1. Unlike leukemia, patients with lymphomatous marrow involvement often had patchy, often discrete, areas of low signal intensity, representing focal marrow infiltration. Five of six patients in this study with lymphoma detected by histologic examination also had marrow lesions seen on MR. An additional four patients had marrow lesions detected by MR that were not detected on initial marrow biopsies; two of these had marrow involvement proven on subsequent biopsies, one had disease isolated to the vertebrae that was never pathologically documented, and one had progression of disease in the marrow documented by MR without biopsy confirmation. These results indicate that marrow involvement with lymphoma can be detected by MR imaging and that MR can complement bone marrow biopsy.

Hematopoietic stem-cell transplantation for treatment-related leukemia or myelodysplasia.

PURPOSE: This report describes results of related or unrelated hematopoietic stem-cell transplants in 111 patients with treatment-related leukemia or myelodysplasia performed consecutively at the Fred Hutchinson Cancer Research Center between December 1971 and June 1998, and identifies patient and treatment characteristics associated with survival and relapse. PATIENTS AND METHODS: At transplantation, 56 patients had treatment-related secondary acute myeloid leukemia (AML), 15 had refractory anemia with excess blasts in transition (RAEB-T), 23 had refractory anemia with excess blasts (RAEB), 15 had refractory anemia (RA), and two had refractory anemia with ringed sideroblasts (RARS). Conditioning regimens were total-body irradiation (TBI) and chemotherapy for 60 patients, busulfan (BU) 14 to 16 mg/kg and cyclophosphamide (CY) 120 mg/kg (BUCY) for 27 patients, BU targeted to 600 to 900 ng/mL plasma steady-state concentration with 120 mg/kg CY (BUCY-t) for 22 patients, and miscellaneous chemotherapy for two patients. The donors were HLA-identical or partially identical family members for 69 patients and unrelated donors for 42 patients. RESULTS: The 5-year disease-free survival was 8% for TBI, 19% for BUCY, and 30% for BUCY-t (P =.006). The 5-year cumulative incidence of relapse was 40% for secondary AML, 40% for RAEB-T, 26% for RAEB, and 0% for RA or RARS (P =.0009). The 5-year cumulative incidence of nonrelapse mortality after TBI was 58%; after BUCY, 52%; and after BUCY-t, 42% (P =.02). CONCLUSION: Patients at risk for treatment-related leukemia or myelodysplasia should be followed closely and be considered for stem-cell transplantation early in the course of myelodysplasia using conditioning regimens such as BUCY-t designed to reduce nonrelapse mortality.

Ovarian function following marrow transplantation for aplastic anemia or leukemia.

One hundred eighty-seven women between 13 and 49 years of age had ovarian function evaluated from 1 to 15 years (median, 4) after marrow transplant for aplastic anemia or leukemia. Among 43 women transplanted for aplastic anemia following 200 mg/kg cyclophosphamide (CY), all 27 less than 26 years of age, but only five of 16 greater than 26 years of age recovered normal ovarian function. Nine of the 43 have had 12 pregnancies, resulting in eight live births, and two elective and two spontaneous abortions. All eight children are normal. Nine of 144 women transplanted for leukemia following 120 mg/kg CY and 9.20 to 15.75 Gy total body irradiation (TBI) recovered ovarian function. Two of these nine have had three pregnancies, resulting in two spontaneous and one elective abortion. The probability of having ovarian failure was 0.35 by 7 years for patients receiving CY alone and was 1.00 at 1 year for patients receiving CY plus TBI (P less than .0001). By 7 years after transplant the probabilities of having normal ovarian function were 0.92 after CY alone and 0.24 after CY plus TBI (P less than .0001). Multivariate analysis showed that TBI was the only factor significantly influencing ovarian failure and that both TBI and greater patient age at transplant were significantly associated with a decreased probability of recovering normal ovarian function. These data demonstrate that after high-dose CY, recovery of ovarian function occurs in younger women and in a minority of older women, but after CY and TBI, recovery occurs in only a few younger women and none of the older women.

High-dose cytarabine and total body irradiation with or without cyclophosphamide as a preparative regimen for marrow transplantation for acute leukemia.

Twenty-nine patients were conditioned for allogeneic marrow transplant with cytarabine (ara-C) (3 g/m2 every 12 hours for 12 doses) and total body irradiation (TBI) (200 cGy daily for six days) with or without cyclophosphamide (CY) (60 mg/kg) to determine toxicity and efficacy. Four patients had chronic myelogenous leukemia (CML) in accelerated phase or blast crisis, and 25 patients had acute leukemia, 24 at stages later than first remission. Three patients (10%) had fatal regimen-related toxicity and another 10% experienced severe toxicity in at least one organ system. The addition of CY to the ara-C and TBI regimen was not associated with an increase in the frequency of severe toxicity. Twenty-five of 29 patients engrafted eight to 33 days posttransplant: three died early before engraftment, and one patient failed to engraft. Ten of 29 patients are alive without disease, and the actuarial probability of disease-free survival for the entire group at 3 years is 33%. Three of ten patients with acute nonlymphocytic leukemia (ANL), six of 15 with acute lymphocytic leukemia (ALL), and one of four with CML are alive and disease free 25 to 42 months (median, 30 months) after transplant. High-dose ara-C (HDara-C) and TBI with or without CY can be administered with approximately the same toxicity as CY plus TBI. Phase III studies appear warranted to determine if these newer regimens provide improved results compared with currently used regimens.

High-dose cyclophosphamide, carmustine, and etoposide followed by autologous bone marrow transplantation in patients with lymphoid malignancies who have received dose-limiting radiation therapy.

PURPOSE: To evaluate high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) in patients with lymphoid malignancy who had received prior radiation therapy. PATIENTS AND METHODS: Fifty-seven patients with non-Hodgkin's lymphoma (NHL; n = 23), Hodgkin's disease (HD, n = 32), or acute lymphoblastic leukemia (ALL; n = 2) with a history of previous radiation therapy were treated with cyclophosphamide (Cy; 7.2 g/m2), carmustine (300 mg/m2 or 600 mg/m2), and etoposide (2,400 mg/m2) (CBV) followed by ABMT. RESULTS: The projected 2-year probabilities of survival, event-free survival (EFS), and relapse were .31, .24, and .76, respectively. For patients with intermediate- and high-grade lymphoma and HD the probabilities were .27, .10, and .14 for EFS and .57, .90, and .77 for relapse. The probability of nonrelapse mortality in the first 100 days post-ABMT was 33%. Idiopathic pneumonia syndrome (IPS) was observed in no patients who received carmustine 300 mg/m2 and 23% of patients who received carmustine 600 mg/m2 (P = .05). Eight-three percent of patients who received mediastinal radiation therapy less than 3 months before transplant developed IPS, compared with 13% who received radiation therapy more than 3 months before transplant (P = .001). CONCLUSION: ABMT following high-dose CBV resulted in long-term disease-free survival in 25% of patients with lymphoid malignancies who had previously received dose-limiting radiation therapy. Fatal IPS and a high relapse rate were major factors limiting successful outcome following ABMT. The morbidity and mortality rates associated with the administration of carmustine 600 mg/m2 were prohibitively high, especially in patients who received mediastinal radiation immediately before ABMT, and were not associated with a decrease in post-ABMT relapse.

Autologous marrow transplantation for patients with acute myeloid leukemia in untreated first relapse or in second complete remission.

PURPOSE: This study compares outcomes of autologous bone marrow transplantation (ABMT) in patients with acute myeloid leukemia (AML) in untreated first relapse (REL1) or in second complete remission (REM2). PATIENTS AND METHODS: Forty-seven patients with AML in REL1 (n = 21) or in REM2 (n = 26) were treated with busulfan (BU) and cyclophosphamide (CY) with or without total-body irradiation (TBI) followed by ABMT. All REL1 patients and four REM2 patients had marrow stored during first remission (REM1). Twenty-seven had marrow stored with and 20 without treatment in vitro with 4-hydroperoxycyclophosphamide (4-HC). Eighteen patients received BU and CY and 29 received BU, CY, and TBI. REL1 patients relapsed within a median of 9 months (range, 2 to 26) after marrow harvest and were transplanted a median of 30 days (range, 9 to 87) from detection of relapse. RESULTS: With a median follow-up of 2.1 years (range, 0.4 to 5.3), 19 patients survive in remission (10 of 21 in REL1; nine of 26 in REM2). The actuarial probabilities of relapse-free survival at 2 years for patients transplanted in REL1 and REM2 were 45% +/- 22% and 32% +/- 18%, respectively (P = .33). The corresponding probabilities of relapse were 30% +/- 26% and 44% +/- 23%, respectively (P = .45). No conclusions could be drawn about the benefits of adding TBI to BU plus CY. There were no significant differences in neutrophil or platelet recovery or in posttransplant probabilities of relapse and nonrelapse mortality between patients who received marrow treated or not treated with 4-HC. CONCLUSION: These results suggest that ABMT may produce long-term leukemia-free survival in approximately one third of patients with AML in REL1 or in REM2. There is no apparent clinical advantage in attempting to obtain second remissions in relapsed patients before ABMT if marrow has been cryopreserved during REM1. Although a strategy of transplantation in REL1 has advantages for the patient, such an approach involves the storage of marrow, which may not be used, and is impractical without the coordinated support of the treating physician, the patient, and the marrow transplant center.

Relapse of acute leukemia after marrow transplantation: natural history and results of subsequent therapy.

Of 455 acute nonlymphocytic leukemia (ANL) patients who underwent marrow transplantation, 95 (21%) relapsed a median of 6.5 months posttransplantation and 62 received further treatment. Twenty achieved remission. Success of therapy was related to the length of time from marrow transplant to relapse and to the use of cytarabine (Ara-C) and daunomycin. Aggressive chemotherapy for patients relapsing within 100 days of marrow transplant was associated with a high incidence of early death (six of 14 patients) and a low probability of remission (one of 14). Of 23 patients who relapsed in excess of 1 year from marrow transplant, 15 achieved a complete remission. The median disease-free survival is 6 months (range, 0.4 to 53+ months). Acute lymphocytic leukemia (ALL) recurred in 130 of 366 patients (36%), and 94 received further therapy. Fifty-two achieved a remission. Remissions were more common in late relapse patients (greater than 1 year from transplantation): 65% v 7% for those relapsing within 100 days from transplant (P less than .05). Testicular relapse occurred in 11 patients and was the sole site of relapse in seven. Three are alive and free of disease 58 to 109+ months after relapse. The median survival for the treated patients is 10.5 months (range, 5 to 109+ months). We propose that reinduction be attempted in all patients relapsing greater than 1 year from marrow transplantation. Ara-C and daunomycin should be employed in the treatment of ANL. The decision for treatment of patients relapsing earlier than 1 year should be made on an individual basis.

Analysis of prognostic factors for the outcome of marrow transplantation or further chemotherapy for patients with acute nonlymphocytic leukemia in first remission.

To test whether variables at diagnosis can identify patients with acute nonlymphoblastic leukemia (ANL) for whom bone marrow transplantation (BMT) is more likely to be of benefit and those for whom continued chemotherapy is a better approach, the association of 15 clinical and laboratory factors with outcome was investigated among 220 patients (ages 1 to 53 years) treated with cyclophosphamide and total body irradiation (TBI) followed by allogeneic BMT, and among 392 patients (ages 13 to 50) administered intensive chemotherapy. In the BMT group, female sex, younger age, the absence of hepatitis during induction, a larger percentage of circulating blasts, and a shorter duration of symptoms were associated with longer survival, whereas only female sex and younger age favorably influenced disease-free survival (DFS). In the chemotherapy group, younger age, lower WBC at diagnosis, a single successful induction course, and the absence of circulating promyelocytes were associated with longer survival, whereas only a lower WBC and a lower percentage of peripheral neutrophils were associated with longer DFS. Estimated regression coefficients for treatment-by-prognostic-factor interactions were used to characterize subgroups of patients in which one treatment or the other produced better outcomes. BMT and chemotherapy produced similar durations of survival in a subset of patients characterized by many or all of the following: older age, male sex, achievement of complete remission (CR) after one induction, and absence of circulating blast cells at presentation. These data suggest that, using pretreatment variables, subgroups of patients can be identified for whom either BMT or continued chemotherapy is most likely to be beneficial.

Treatment of refractory non-Hodgkin's lymphoma with radiolabeled MB-1 (anti-CD37) antibody.

The biodistribution, toxicity, and therapeutic potential of anti-CD37 monoclonal antibody (MoAb) MB-1 labeled with iodine 131 (131I) was evaluated in ten patients with advanced-, low- or intermediate-grade non-Hodgkin's lymphomas who failed conventional treatment. Sequential dosimetric studies were performed with escalating amounts of antibody MB-1 (0.5, 2.5, 10 mg/kg) trace-labeled with 5 to 10 mCi 131I. Serial tumor biopsies and gamma camera imaging showed that the 10 mg/kg MoAb dose yielded the best MoAb biodistribution in the ten patients studied. Biodistribution studies in the five patients with splenomegaly and tumor burdens greater than 1 kg indicated that not all tumor sites would receive more radiation than normal organs, and these patients were therefore not treated with high-dose radioimmunotherapy. The other five patients did not have splenomegaly and had tumor burdens less than 0.5 kg; all five patients in this group showed preferential localization and retention of MoAb at tumor sites. Four of these patients have been treated with 131I (232 to 608 mCi) conjugated to anti-CD37 MoAb MB-1, delivering 850 to 4,260 Gy to tumor sites. Each of these four patients attained a complete tumor remission (lasting 4, 6, 11+, and 8+ months). A fifth patient, whose tumor did not express the CD37 antigen, was treated with 131I-labeled anti-CD20 MoAb 1F5 and achieved a partial response. Myelosuppression occurred 3 to 5 weeks after treatment in all cases, but there were no other significant acute toxicities. Normal B cells were transiently depleted from the bloodstream, but immunoglobulin (Ig) levels were not affected, and no serious infections occurred. Two patients required reinfusion of previously stored autologous, purged bone marrow. Two patients developed asymptomatic hypothyroidism 1 year after therapy. The tolerable toxicity and encouraging efficacy warrant further dose escalation in this phase I trial.

Regimen-related toxicity and early posttransplant survival in patients undergoing marrow transplantation for lymphoma.

Ninety-five patients transplanted for malignant lymphoma were retrospectively evaluated for regimen-related toxicity (RRT) and early posttransplant survival. Nineteen patients developed life-threatening (grade 3) or fatal (grade 4) RRT in one or more organs. Grade 3 or 4 RRT was more common in patients with advanced disease versus those transplanted earlier in their course (P = .008), and was more common in patients with advanced disease conditioned with cytarabine (Ara-C)/total body irradiation (TBI) versus those prepared with cyclophosphamide (CY)/TBI (P = .033). There was no significant difference in the incidence of grade 3 or 4 toxicity in autologous, histocompatibility locus antigen (HLA)-identical, or HLA-mismatched marrow recipients. Grade 3 or 4 RRT tended to be more common and 100-day survival worse in patients with a Karnofsky performance status of less than 90 (P = .063 and .0002, respectively). Patients receiving 20 Gy or more of mediastinal irradiation before coming to transplant had more idiopathic or cytomegalovirus (CMV) interstitial pneumonitis than those who received less than 20 Gy (30% v 9%, P = .027). The probability of survival decreased with the number of organs in which toxicity was observed (P = .0001). Severe or fatal toxicities directly related to the preparative regimen are a significant problem in the treatment of patients with advanced malignant lymphoma and can be reduced by carrying out transplantation earlier in the course of the disease.

High-dose fractionated total-body irradiation, etoposide, and cyclophosphamide followed by autologous stem-cell support in patients with malignant lymphoma.

PURPOSE: To evaluate a high-dose treatment regimen of fractionated total-body irradiation (TBI), etoposide, and cyclophosphamide (Cy) followed by autologous stem-cell transplantation (ASCT) in patients with malignant lymphoma. PATIENTS AND METHODS: Fifty-three patients with non-Hodgkin's lymphoma (NHL; n = 43) or Hodgkin's disease (HD; n = 10) received 12.0 Gy of fractionated TBI, etoposide 60 mg/kg, and Cy 100 mg/kg followed by infusion of autologous hematopoietic stem cells. RESULTS: Thirty-one of 53 patients are alive a median of 643 (range, 177 to 1,144) days after transplant. The 2 year Kaplan-Meier (K-M) estimates of survival, event-free survival (EFS), and relapse for all 53 patients were 54%, 45%, and 43%, respectively. Sixteen of 24 patients with less advanced disease and 10 of 29 patients with more advanced disease survive free of disease for K-M estimates of EFS of 61% and 31%, respectively (P = .006). The K-M estimates of relapse were 34% for patients with less advanced disease and 53% (P = .05) for patients with more advanced disease. The K-M estimates of dying from causes other than relapse were 8% in patients with less versus 25% in patients with more advanced disease (P = .09). CONCLUSION: These data indicate that approximately 60% of patients transplanted early after failure of initial therapy for malignant lymphoma are projected to be disease-free more than 2 years after treatment with fractionated TBI, etoposide, and Cy and infusion of autologous hematopoietic stem cells. The transplant-related mortality rate is low and relapse is the main cause of treatment failure in patients with less advanced disease. For patients with more advanced disease, the K-M estimates of both transplant-related deaths (25%) and relapse (53%) remain major problems.