Maintenance rituximab after autologous stem cell transplantation in patients with mantle cell lymphoma.

BACKGROUND: High-dose therapy and autologous stem cell transplantation (ASCT) improves outcomes for patients with mantle cell lymphoma (MCL), but relapse ultimately occurs in most patients. Recently presented interim results from a phase III prospective trial suggest maintenance rituximab (MR) after ASCT for MCL improves progression-free survival (PFS). The maturation of these data and any benefit of MR on overall survival (OS) remain to be defined. PATIENTS AND METHODS: In this retrospective study, we examined a cohort of consecutive patients with MCL that underwent ASCT for MCL at our center and evaluated their outcomes according to whether they received MR after ASCT (n = 50) or did not (n = 107). MR was treated as a time-dependent covariate to account for variation in timing of its initiation. RESULTS: MR was associated with an improved PFS [hazard ratio (HR) 0.44; confidence interval (CI) (0.24-0.80), P = 0.007] and overall survival (OS; HR 0.46; CI 0.23-0.93, P = 0.03) following a multivariate adjustment for confounding factors with a median follow-up of ∼5 years. Grade 4 neutropenia was increased (34% versus 18%, P = 0.04) in the MR group, but no effect on the rate of mortality unrelated to relapse was observed. CONCLUSIONS: These data support that MR after ASCT for MCL confers a benefit in PFS and additionally suggest it may improve OS. General application of this strategy will require confirmation of benefit in prospective randomized trials.

Gender-related survival differences associated with polymorphic variants of estrogen receptor-ß (ERß) in patients with metastatic colon cancer.

Estrogen replacement therapy in women has shown a protective effect on the development of colonic carcinomas. Gender-related differences in the development of colonic carcinomas have also been reported. Estrogen receptor-ß (ERß) is expressed in colon carcinomas and has shown prognostic value in colon cancer patients. This study investigated an ERß 3' non-coding polymorphism associated with transcriptional activity to determine clinical outcome in patients with metastatic colon cancer. Genomic DNA from 318 metastatic colon cancer patients, 177 males and 141 females, were collected from 1992 to 2003. These patients were analyzed for CA repeat polymorphism of the ERß gene. Gender-related survival differences were associated with an ERß (CA)n repeat polymorphism (P for interaction=0.003, the likelihood ratio test). Female patients with any short<22 (CA)n repeat alleles had shorter overall survival (OS) compared with female patients who had both long≥22 (CA)n repeat alleles. In the male patients, the opposite OS difference was found. This study supports the role of an ERß (CA)n repeat polymorphism as a prognostic marker in metastatic colon cancer; however, this prognostic factor had opposite implications based on gender.

Phytohemagglutinin-induced differentiation and blastogenesis of precursor T cells from mouse bone marrow.

The cells in mouse bone marrow (BM) capable of responding to phytohemagglutinin (PHA) were shown to be precursor T cells in experiments employing athymic mice, immunofluorescence, and specific lysis of T or B cells with cytotoxic antisera + complement. In contrast, the responses of lymph node (LN) and spleen (Spl) cells to this mitogen were shown by the same techniques to rely upon resident populations of mature T lymphocytes in these peripheral lymphoid organs. Cytolysis of T cells with anti-theta (anti-Thy 1), anti-thymocyte, or anti-brain antisera abolished the PHA responses of LN and Spl, but had no appreciable effect on the BM PHA response. Lysis of B cells with anti-mouse gamma globulin or anti-mouse IgM antisera had no significant effect on either Spl or BM blastogenesis in response to this lectin. Immunofluorescent studies with fluoresceinated anti-brain sera demonstrated acquisition of T-cell surface antigens by BM null lymphocytes during the blastogenic response of this tissue to PHA. The results of these immunofluorescence experiments were reproducible even when marrow obtained from nude mice and pretreated with anti-brain serum plus complement was employed. The implications of these findings with regard to prophylaxis against graft versus host disease in BM transplant recipients are discussed.

Prognostic value of regulatory T cells, lymphoma-associated macrophages, and MUM-1 expression in follicular lymphoma treated before and after the introduction of monoclonal antibody therapy: a Southwest Oncology Group Study.

BACKGROUND: The purpose was to examine the prognostic impact of features of tumor cells and immune microenvironment in patients with follicular lymphoma treated with and without anti-CD20 monoclonal antibody therapy. PATIENTS AND METHODS: Tissue microarrays were constructed from archived tissue obtained from patients on three sequential Southwest Oncology Group (SWOG) trials for FL. All three trials included anthracycline-based chemotherapy. Anti-CD20 monoclonal antibodies were included for patients in the latter two trials. Immunohistochemistry was used to study the number and distribution of cells staining for forkhead box protein P3 (FOXP3) and lymphoma-associated macrophages (LAMs) and the number of lymphoma cells staining for myeloma-associated antigen-1 (MUM-1). Cox proportional hazards regression was used to evaluate the association between marker expression and overall survival (OS). RESULTS: The number or pattern of infiltrating FOXP3 cells and LAMs did not correlate with OS in sequential SWOG studies for FL. The presence of MUM-1 correlated with lower OS for patients who received monoclonal antibody but not for those treated with chemotherapy alone. CONCLUSIONS: Immune cell composition of lymph nodes did not correlate with OS in this analysis of trials in FL. The mechanism of the observed correlation between MUM-1 expression and adverse prognosis in patients receiving monoclonal antibody therapy requires confirmation.

The impact of histologic grade on the outcome of high-dose therapy and autologous stem cell transplantation for follicular lymphoma.

The impact of the follicular lymphoma (FL) histologic grade on outcomes after high-dose therapy (HDT) and autologous stem cell transplantation (ASCT) is unknown. We evaluated 219 consecutive patients with grades 1-3 FL who underwent HDT and ASCT at our center. Overall survival (OS), progression-free survival (PFS), relapse and non-relapse mortality (NRM) was estimated for each grade after controlling for other predictive factors. The number of patients with grades 1, 2 and 3 FL was 106 (48%), 75 (34%) and 38 (17%), respectively. Five-year outcome estimates for the entire cohort included 60% OS, 39% PFS and 46% relapse (median follow-up=7.8 years). PFS and relapse were nearly identical among patients with grade 3 FL versus grades 1-2 FL after adjusting for other contributing factors (hazard ratio (HR)=0.90, P=0.68; HR=1.07, P=0.80, respectively). The hazard for mortality (HR=0.70, P=0.23) and NRM (HR=0.33, P=0.07) was non-significantly lower among patients with grade 3 FL compared to patients with grades 1-2 disease. Factors associated with inferior PFS included elevated lactate dehydrogenase (HR=1.52, P=0.03), chemoresistance (HR=1.82, P=0.02), > or =2 prior therapies (HR=1.8, P=0.03) and prior radiation (HR=1.99, P=0.003). These data suggest that the histologic grade of FL does not impact PFS or relapse following HDT and ASCT.

A prospective, randomized study of cryotherapy during administration of high-dose melphalan to decrease the severity and duration of oral mucositis in patients with multiple myeloma undergoing autologous peripheral blood stem cell transplantation.

Forty patients with multiple myeloma scheduled to receive melphalan 200 mg/m(2) followed by autologous stem cell transplantation were randomly assigned to receive oral cryotherapy or room temperature normal saline rinses 30 min before and for 6 h after high-dose therapy. Patients were evaluated for the development of mucositis using the National Cancer Institute grading system as well as evaluation of secondary measures such as days of total parenteral nutrition (TPN), narcotic use, hospitalization, weight loss and resumption of oral caloric intake for 28 days after transplant. Patients self-scored their pain, swallowing, drinking, eating, sleeping and taste alterations for 28 days. The primary end point of this trial was the incidence of grades 3-4 mucositis. Compared to the normal saline group, patients using cryotherapy experienced less grade 3-4 mucositis, 14 vs 74%, P=0.0005. Patients receiving cryotherapy also had statistically lower uses of narcotics and TPN, although there were no differences in length of hospitalization or weight loss. Patient-reported pain was significantly lower and activities were significantly better in the cryotherapy group.

Intracellular catabolism of radiolabeled anti-mu antibodies by malignant B-cells.

The endocytosis and degradation of 125I-labeled anti-mu monoclonal antibody DA4-4 by a Burkitt's lymphoma cell line was investigated using biochemical, chromatographic, electrophoretic, radioautographic, and electron microscopic techniques. 125I-DA4-4 was rapidly internalized by Ramos cells and routed from endosomes to lysosomes. Proteolysis of radiolabeled antibodies began in a late endosomal compartment, but lysosomes were primarily responsible for the terminal degradation of 125I-DA4-4. Catabolism of 125I-DA4-4 could be inhibited by 74-95% by blocking its delivery to late endosomes and lysosomes by incubation at 18 degrees C, by neutralizing the pH in intracellular organelles with monensin or ammonium chloride, or by inhibiting lysosomal enzymes with leupeptin. Radiolabeled antibodies synthesized using the chloramine T or Iodo-Gen techniques were degraded three times faster than conjugates made using a nonmetabolizable 125I-tyramine cellobiose adduct. Five major intermediate metabolites (Mr 48,000, 42,000, 25,000, 15,000, and 10,000) were generated during the intracellular catabolism of 125I-DA4-4, but 125I-tyrosine was responsible for 95% of the small-molecular-weight metabolites released by cells into the culture medium. We anticipate that a full comprehension of the catabolism of radiolabeled antibodies by tumor cells will make possible the development of clinical interventions which will enhance the retention of radioimmunoconjugates by hematologic malignancies and improve the efficacy of radioimmunotherapy.

Endocytosis and degradation of murine anti-human CD3 monoclonal antibodies by normal and malignant T-lymphocytes.

Treatment of lymphoid malignancies with monoclonal antibodies (mAbs) and immunoconjugates is a promising new immunotherapeutic approach. However, few published studies have examined in detail the subcellular fate of antibodies following binding to lymphocyte cell surface antigens. In this study, we have investigated the disposition of monoclonal anti-CD3 antibody 64.1 following binding to normal and malignant T-lymphocytes by using cellular radioimmunoassays and immunoperoxidase and immunogold electron microscopy. Anti-CD3 mAbs were predominantly cleared from the cell membrane at 37 degrees C by receptor-mediated endocytosis, although passive shedding of antibody was also observed. Internalized antibody was sequentially transferred from coated pits to receptosomes and eventually to lysosomes. Intralysosomal degradation appeared to be the ultimate fate of internalized radiolabeled mAbs and was followed by exocytosis of free 125I to the culture medium. Ammonium chloride and monensin were potent inhibitors of lysosomal degradation of 125I-anti-CD3 mAbs and caused intracellular trapping of radiolabeled antibodies. The rapid endocytosis, degradation, and exocytosis of antibody observed in these studies elucidate the mechanism of the improved efficacy of anti-CD3 immunoconjugates when used in conjunction with inhibitors of lysosomal action.

Inhibition of catabolism of radiolabeled antibodies by tumor cells using lysosomotropic amines and carboxylic ionophores.

The rates of degradation of radioiodinated monoclonal antibodies (MoAbs) by malignant T- and B-lymphoid cells were studied in the presence and absence of a variety of pharmacological agents known to affect the intracellular metabolism of internalized ligands. 125I-MoAbs directed against the CD2, CD3, CD5, and anti-mu surface antigens underwent rapid endocytosis, followed by prompt degradation with release of greater than or equal to 50% of the initially bound radioactivity as free, trichloroacetic acid-soluble 125I within 24 h. Lysosomotropic amines (chloroquine, ammonium chloride, amantadine), carboxylic ionophores (monensin, nigericin), calcium channel blockers (verapamil), thionamides (propylthiouracil), lysosomal enzyme inhibitors (leupeptin), and colchicine all inhibited metabolism of radioiodinated MoAbs and enhanced retention of 125I-MoAbs by tumor cells. The most effective agents (e.g., monensin, nigericin) diminished the release of free 125I by greater than 90% and enhanced retention of radioactivity by greater than 300% at 24 h. Experiments with immunoperoxidase electron microscopy and Percoll gradient fractionation of organelles from disrupted cells suggested that high concentrations of monensin (10-20 microM) delayed transfer of 125I-MoAbs to lysosomes, but other mechanisms (e.g., pH neutralization) were operative at lower concentrations (1-3 microM). Clinical administration of these agents may enhance retention of radioimmunoconjugates by tumor cells, resulting in improved radioimmunoscintigraphy and radioimmunotherapy.

Radiolabeled antibody targeting of the HER-2/neu oncoprotein.

The HER-2/neu oncogene encodes a Mr 185,000 transmembrane phosphoglycoprotein which is overexpressed in 25-35% of breast and ovarian neoplasms and portends a poor prognosis. We have studied the feasibility of targeting this oncoprotein, designated p185, with radioiodinated murine monoclonal antibodies (muMABs) 4D5 and 7C2, which recognize distinct epitopes on its extracellular domain. The rates of internalization and catabolism of these antibodies were analyzed by cellular radioimmunoassay and electron microscopy. After binding to NIH3T3 HER-2/neu cells, which show high surface expression of p185, the muMABs were endocytosed via coated pits, routed to lysosomes, and degraded. Approximately 44% of 125I-4D5 and 39% of 125I-7C2 were catabolized by tumor cells after 24 h. The biodistribution of radiolabeled 4D5 and 7C2 were evaluated in beige/nude mice bearing s.c. NIH3T3 HER-2/neu grafts. A high specificity of localization was seen with tumor:organ ratios of activity generally ranging from 5:1 to 30:1. However, the percentage injected dose of radioactivity per gram of tumor declined sharply from 25% at 24 h to 5% at 120 h postinjection. Treating the animals with 400-700 muCi 131I-4D5 caused a marked inhibition of tumor growth, although no mice were cured. Unlabeled 4D5 had no effect on tumor progression in this model, but administering 400-700 muCi of 131I-DA4-4, an isotype-matched irrelevant muMAB, resulted in an intermediate degree of growth retardation. Analysis of kinetic blood data and whole-body time-activity curves indicated that the irrelevant conjugate remained in the body 2-3 times longer than 131I-4D5. Radioiodinated anti-HER-2/neu muMABs are attractive agents for radioimmunodiagnosis and radioimmunotherapy of aggressive HER-2/neu-positive breast and ovarian carcinomas, but effective strategies for retarding intratumoral catabolism may be necessary to optimize their clinical utility.

Endocytosis and degradation of monoclonal antibodies targeting human B-cell malignancies.

Seven murine monoclonal antibodies (MoAbs) recognizing differentiation antigens present on B-lymphocytes were analyzed in preclinical studies for their potential use for antibody-targeted therapy of B-cell malignancies. MoAbs HD37 (anti-CD19), 1F5 (anti-CD20), HD6 (anti-CD22), MB-1 (anti-CD37), G28-5 (anti-CDw40), 7.2 (anti-class II), and DA4-4 (anti-IgM) were studied for their binding avidities, immunoreactivities, isotypes, endocytosis rates, degradation rates, and number of binding sites on Daudi cells. Lineweaver-Burke analyses of 125I-labeled MoAbs demonstrated immunoreactivities ranging from 59 to 92%. Scatchard analyses of 125I-MoAbs demonstrated that five of the antibodies had binding avidities in excess of 10(9) L/M, whereas MoAbs 1F5 and HD37 had avidities of 3-4 x 10(8) L/M. CD20, CD37, mu, and HLA Class II were found to be highly expressed (200,000-400,000 binding sites/cell) on Daudi cells whereas CD19, CD22, and CDw40 were less densely expressed (80,000-100,000 sites/cell). DA4-4 (mu), HD6 (CD22), and G28-5 (CDw40) were rapidly internalized by cells, HD37 (CD19) and MB-1 (CD37) underwent endocytosis at an intermediate rate, and 7.2 (class II) and 1F5 (CD20) were internalized slowly. Trichloroacetic acid precipitation and high-performance liquid chromatography revealed the following relative rates of 125I-MoAb degradation: DA4-4 (mu) greater than HD6 (CD22) greater than HD37 (CD19) greater than G28-5 (CDw40) greater than MB-1 (CD37) greater than 1F5 (CD20) greater than 7.2 (class II).

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.

Improving the tumor retention of radioiodinated antibody: aryl carbohydrate adducts.

Improved methods for attaching radioiodine to monoclonal antibodies have been developed. Ten aryl carbohydrate adducts were synthesized by the reductive amination of a carbohydrate with an aryl amine, using sodium cyanoborohydride as a reducing agent. After purification by chromatography and characterization by nuclear magnetic resonance they were iodinated using the chloramine-T method. Iodinated adducts were activated with cyanuric chloride and incubated with protein at room temperature. The immunoreactivity and avidity of radioiodinated tyramine cellobiose (TCB) labeled antibody were fully preserved when compared to electrophilically radioiodinated antibody. Radioiodinated TCB-and tyramine glucose-labeled monoclonal antibodies showed much greater intracellular retention of radioiodine when compared to electrophilically radioiodinated monoclonal antibodies. Neither radioiodinated tyramine nor radioiodinated TCB had any specific tissue uptake or retention. In mice the retention of radioiodinated TCB labeled anti-Thy-1.1 antibody (1A14) by Thy-1.1-bearing lymphoma cells was 2 times greater than that of chloramine-T labeled 1A14 antibody, whereas the plasma clearance curve and uptake in normal tissues was not changed. This method of radioiodinating monoclonal antibodies increases the retention time of radioiodine in tumor and thus may obviate the problem of intracellular deiodination, a perceived disadvantage of electrophilically iodinated antibodies, with respect to tumor retention of radioactivity.

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.

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.

Bendamustine, etoposide and dexamethasone to mobilize peripheral blood hematopoietic stem cells for autologous transplantation in patients with multiple myeloma.

Chemotherapeutic agents without cross-resistance to prior therapies may enhance PBSC collection and improve patient outcomes by exacting a more potent direct antitumor effect before autologous stem cell transplant. Bendamustine has broad clinical activity in transplantable lymphoid malignancies, but concern remains over the potential adverse impact of this combined alkylator-nucleoside analog on stem cell mobilization. We performed a prospective, nonrandomized phase II study including 34 patients with multiple myeloma (MM) (n=34; International Staging System (ISS) stages I (35%), II (29%) and III (24%); not scored (13%)) to evaluate bendamustine's efficacy and safety as a stem cell mobilizing agent. Patients received bendamustine (120 mg/m2 IV days 1, 2), etoposide (200 mg/m2 IV days 1-3) and dexamethasone (40 mg PO days 1- 4) (bendamustine, etoposide and dexamethasone (BED)) followed by filgrastim (10 µg/kg/day SC; through collection). All patients (100%) successfully yielded stem cells (median of 21.60 × 106/kg of body weight; range 9.24-55.5 × 106/kg), and 88% required a single apheresis. Six nonhematologic serious adverse events were observed in 6 patients including: neutropenic fever (1, grade 3), bone pain (1, grade 3) and renal insufficiency (1, grade 1). In conclusion, BED safely and effectively mobilizes hematopoietic stem cells.

A randomized study of melphalan 200 mg/m(2) vs 280 mg/m(2) as a preparative regimen for patients with multiple myeloma undergoing auto-SCT.

We aimed to examine whether doses of melphalan higher than 200 mg/m(2) improve response rates when used as conditioning before autologous transplant (ASCT) in multiple myeloma (MM) patients. Patients with MM, n=131, were randomized to 200 mg/m(2) (mel200) vs 280 mg/m(2) (mel280) using amifostine pretreatment. The primary end point was the proportion of patients achieving near complete response (⩾nCR). No treatment-related deaths occurred in this study. Responses following ASCT were for mel200 vs mel280, respectively, ⩾nCR 22 vs 39%, P=0.03, ⩾PR 57 vs 74%, P=0.04. The hazard of mortality was not statistically significantly different between groups (mel200 vs mel280; hazard ratio (HR)=1.15 (95% confidence interval (CI), 0.62-2.13, P=0.66)) nor was the rate of progression/mortality (HR=0.81 (0.52-1.27, P=0.36)). The estimated PFS at 1 and 3 years were 83 and 46%, respectively, for mel200 and 78 and 54%, respectively, for mel280. Amifostine and mel280 were well tolerated, with no grade 4 regimen-related toxicities and only one grade 3 mucositis (none with mel200) and three grade 3 gastrointestinal (GI) toxicities (two in mel200). Hospitalization rates were more frequent in the mel280 group (59 vs 43%, P=0.08). Mel280 resulted in a higher major response rate (CR+nCR) and should be evaluated in larger studies.

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.

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.