Peripheral blood mononuclear cells (PBMC) were collected after the administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and used as the sole source of hematopoietic stem cells after myeloablative therapy with busulfan (Bu) and cyclophosphamide (Cy). These studies were performed in 12 patients with malignancies (4 non-Hodgkin's lymphoma, 5 breast cancer, 1 testicular carcinoma, 1 Wilm's tumor, and 1 undifferentiated carcinoma) who had bone or bone marrow disease or had low marrow cellularity. rhG-CSF (16 micrograms/kg/d) was administered for 5 to 7 days by subcutaneous injection and PBMC were collected for 2 to 5 days beginning on day 4 after initiation of rhG-CSF, using continuous-flow blood-cell separators that processed 10 to 12 L of whole blood. From a median of three collections, a mean of 24.0 x 10(8) (+/- 10.5 SD) total nucleated cells/kg containing 12.6 x 10(8) (+/- 4.5 SD) mononuclear cells/kg, 7.3 x 10(6) (+/- 4.3 SD) CD34+ cells/kg and 20.5 x 10(4) (+/- 28.1 SD) granulocyte-macrophage colony-forming units (CFU-GM)/kg were harvested and cryopreserved. After the administration of Bu 14 to 17 mg/kg and Cy 120 to 150 mg/kg, PBMC were thawed and infused. One patient received rhG-CSF after the infusion of PBMC and the remaining 11 patients did not receive postinfusion growth factors. Mean days to recovery of neutrophil levels of 0.1, 0.5, and 1.0 x 10(9)/L were 11.4 (range, 9 to 13), 12.7 (range, 10 to 15), and 13.6 (range, 11 to 16) and the mean day to platelet transfusion independence was 13.3 (range, 7 to 49). Time to recovery of neutrophils to 0.5 and 1.0 x 10(9)/L and platelets to 20 x 10(9)/L was more rapid than in historical patients treated with Bu and Cy who received marrow alone or marrow followed by the posttransplant administration of rh-G or GM-CSF. No graft failures have been observed with a follow-up of 4 to 12 months. These results indicate that PBMC collected after rhG-CSF lead to rapid hematopoietic recovery after myeloablative chemotherapy.

Patients with idiopathic, cyclic, and congenital neutropenia have recurrent severe bacterial infections. One hundred twenty-three patients with recurrent infections and severe chronic neutropenia (absolute neutrophil count < 0.5 x 10(9)/L) due to these diseases were enrolled in this multicenter phase III trial. They were randomized to either immediately beginning recombinant human granulocyte colony-stimulating factor (filgrastim) (3.45 to 11.50 micrograms/kg/d, subcutaneously) or entering a 4-month observation period followed by filgrastim administration. Blood neutrophil counts, bone marrow (BM) cell histology, and incidence and duration of infection-related events were monitored. Of the 123 patients enrolled, 120 received filgrastim. On therapy, 108 patients had a median absolute neutrophil count of > or = 1.5 x 10(9)/L. Examination of BM aspirates showed increased proportions of maturing neutrophils. Infection-related events were significantly decreased (P < .05) with approximately 50% reduction in the incidence and duration of infection-related events and almost 70% reduction in duration of antibiotic use. Asymptomatic splenic enlargement occurred frequently; adverse events frequently reported were bone pain, headache, and rash, which were generally mild and easily manageable. These data indicate that treatment of patients with severe chronic neutropenia with filgrastim results in a stimulation of BM production and maturation of neutrophils, an increase in circulating neutrophils, and a reduction in infection-related events.

The effect of 5-fluorouracil (5-FU) pretreatment on human bone marrow (BM) progenitor/stem cells and recovery of hematopoiesis after autologous marrow transplant was studied. Twenty-one patients were treated with 5-FU (15 mg/kg to 45 mg/kg) intravenously (IV) for 1 to 3 days administered 6 to 22 days before BM harvest. Post-FU marrow was infused into 15 patients after high-dose cyclophosphamide, carmustine (BCNU), and VP-16 (CBV). Seventeen patients (historical controls) were treated with CBV and autologous BM transplantation but did not receive 5-FU before marrow harvest. The groups were comparable for diagnosis and prior therapy. In the 5-FU-treated group and control group, median recovery times for platelet count to 50,000/mm3 were 20 and 30 days, respectively (P = .007), and for platelet count to 100,000/mm3, 23 and 38 days, respectively (P = .007), while neutrophil recovery was not significantly altered. In vitro cultures with 1 to 7 growth factors (interleukin-1 [IL-1], IL-3, IL-4, IL-6, colony-stimulating factor-1 [CSF-1], granulocyte-macrophage colony-stimulating factor [GM-CSF], and G-CSF) were performed. In 8 of 10 patients whose marrow was studied before and after 5-FU treatment, the numbers of CFU-C responsive to the combination of GM-CSF and IL-3 was increased 6.15-fold by 5-FU pretreatment. In 4 of these patients, thymidine suicide of GM-CSF- and IL-3-stimulated CFU-C ranged from 17% to 42%. High proliferative potential colony-forming cell (HPP-CFC) was observed in low frequency in normal marrow and patient's marrow before 5-FU treatment. In 11 of 16 patients pretreated with 5-FU, increased numbers of HPP-CFC were noted. GM-CSF and IL-3 interacted synergistically to stimulate HPP-CFC. Multifactor combinations, especially GM-CSF + G-CSF + IL-3 + IL-6 + IL-1 + CSF-1 did not increase total colony count or classic HPP-CFC but did result in altered morphology, producing huge, loose colonies. The marrow from patients pretreated with 5-FU is enriched with multifactor-responsive HPP-CFC, renews in vivo granulopoiesis in a manner comparable with marrow harvests without 5-FU pretreatment, and provides accelerated in vivo platelet recovery. This marrow may be an appropriate target marrow for gene insertion in gene-therapy protocols.

Anti-B-blocked ricin (anti-B4-bR) combines the specificity of the anti-B4 (CD19) monoclonal antibody with the protein toxin "blocked ricin." In blocked ricin, affinity ligands are attached to the ricin B-chain to attenuate its lectin binding capacity. In a phase I trial, Anti-B4-bR was administered by 7-day continuous infusion to 12 patients in complete remission after autologous bone marrow transplantation (ABMT) for relapsed B-cell non-Hodgkin's lymphoma (NHL). Patients were treated at 20, 40, and 50 micrograms/kg/d for 7 days. Potentially therapeutic serum levels could be sustained for 3 to 4 days. The maximum tolerated dose was 40 micrograms/kg/d for 7 days (total 280 micrograms/kg). The dose-limiting toxicities were reversible grade IV thrombocytopenia and elevation of hepatic transaminases. Mild capillary leak syndrome was manifested by hypoalbuminemia, peripheral edema (4 patients), and dyspnea (1 patient). Anti-immunotoxin antibodies developed in 7 patients. Eleven patients remain in complete remission between 13 and 26 months post-ABMT (median 17 months). These results show that Anti-B4-bR can be administered with tolerable, reversible toxicities to patients with B-cell NHL in complete remission following ABMT.

Endogenous cytokines are thought to mediate numerous biologic processes and may account for some adverse effects experienced following the administration of recombinant proteins. This study describes the pattern of endogenous cytokine exposure following high-dose chemotherapy. Blood concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), macrophage colony-stimulating factor (M-CSF), and erythropoietin (EPO) were measured by enzyme-linked immunosorbent assay (ELISA) methods in 68 patients receiving the same ablative chemotherapy regimen (cyclophosphamide, cisplatin, carmustine). Patients were grouped according to cellular support (autologous bone marrow [BM] CSF-primed peripheral blood progenitor cells [PBPCs]) and prescribed growth factor (recombinant human granulocyte or granulocyte-macrophage colony-stimulating factor [rHuG-CSF or rHuGM-CSF]). Leukocyte reconstitution was most accelerated in the groups treated with PBPCs and rHuG-CSF. IL-6, M-CSF, and TNF-alpha concentrations were higher in the groups treated with rHuGM-CSF and without PBPCs. Maximal endogenous cytokine concentrations occurred approximately 12 days after BM reinfusion. High concentrations of EPO occurred in patients experiencing significant hypotension despite routine transfusions for hematocrit < 42%. High M-CSF and IL-6 levels were associated with increased platelet transfusion requirements. Concentrations of all four cytokines were significantly higher in patients experiencing renal or hepatic toxicity, with elevations occurring in a predictable sequence and M-CSF elevations occurring first. This report shows that endogenous cytokine concentrations may be influenced by either cellular or CSF support and are associated with differences in platelet reconstitution and organ toxicity.

Two novel preparatory regimens for conditioning of patients with leukemia for allogeneic bone marrow transplantation (BMT) from histocompatible sibling donors have been tested in a phase III trial under the auspices of the Southwest Oncology Group (SWOG 8612). These two regimens consisted either of fractionated total body irradiation and etoposide (FTBI/VP-16) or high-dose busulfan with cyclophosphamide (BU/CY). Only patients who had failed prior conventional management at least once were study eligible, ie, no patients with acute leukemia in first remission (CR) or in first chronic phase (CP) of chronic myelogenous leukemia (CML) participated. Patients were stratified according to the following risk criteria: "good-risk" patients were those who were in second CR of their acute leukemia or in accelerated phase (AP) of CML; "poor-risk" patients had further advanced stages of leukemia. During a 52-month period, 131 patients were registered of whom 122 (93%) were study eligible. Sixty-one eligible patients were randomized to the FTBI/VP-16 arm and 61 to the BU/CY regimen. Of these 122 patients, 114 (93%) proceeded to BMT according to protocol. Posttransplant immunosuppression to prevent graft-versus-host disease (GVHD) consisted of cyclosporine and prednisone (CSA/PSE). Neither overall survival nor disease-free survival (DFS) differed significantly between the two treatment groups (P = .89 and .69, respectively). Estimated DFS for "good-risk" patients who had been prepared with the FTBI/VP-16 regimen was 55% +/- 11%, as compared with patients treated with BU/CY whose DFS figure was 34% +/- 10% (P = .30). For "poor-risk" candidates, the DFS rates at 24 months were 17% +/- 6% (for FTBI/VP-16) and 24% +/- 8% (for BU/CY), respectively (P = .81). These figures do not differ significantly, especially in view of the fact that the "good-risk" patients prepared with the FTBI/VP-16 regimen were younger than those treated with BU/CY. Both regimens were well tolerated with no regimen-related deaths encountered during the 6-week period after BMT. This study also confirmed the efficacy of the CSA/PSE combination in the prevention of GVHD with 23 of 113 (20%) of BMT recipients developing moderate to severe acute GVHD. The leading cause for treatment failure was leukemic relapse (45 of the 114 BMT recipients suffered a recurrence of their leukemia), whereas 38 patients died without evidence of relapse. Thirty-one patients are alive and in continued CR after marrow transplantation; four are alive in relapse.(ABSTRACT TRUNCATED AT 400 WORDS)

Based on preclinical studies showing that CD8+ T lymphocytes of human immunodeficiency syndrome (HIV)-infected subjects have anti-HIV activities, a phase 1 study was undertaken to determine the safety and feasibility of infusing in vitro purified, activated, and expanded CD8+ cells as a therapeutic measure in seven patients with acquired immunodeficiency syndrome (AIDS)-related complex (ARC) or AIDS. Autologous CD8+ cells were first selectively isolated in monoclonal antibody-coated flasks from peripheral blood mononuclear cells recovered by leukapheresis. They were then cultured and expanded with phytohemagglutinin and recombinant interleukin-2 (rIL-2) before infusion. Five cycles of isolations and infusions of increasing numbers of CD8+ T cells were achieved in five of seven subjects. Five cycles could not be completed in two subjects with AIDS whose CD4+ cell counts were < or = 48/microliters. Infusions of CD8+ cells alone were well tolerated. Four patients received rIL-2 by continuous infusion for 5 days with their final cycle of CD8+ cells. All developed reversible adverse effects attributable to rIL-2. After infusion, 111In-labeled CD8+ cells quickly accumulated in the lungs, with less than 10% of the labeled cells remaining in the circulation. After 24 hours, labeled CD8+ cells were reduced in the lungs, but increased and persisted in liver, spleen, and bone marrow. Four of five patients who were treated with multiple infusions of CD8+ cells have improved or remained clinically stable, and the fifth developed Pneumocystis carinii pneumonia but recovered. This study demonstrated that infusion of autologous, in vitro expanded and activated CD8+ cells was feasible and clinically well tolerated in five of seven subjects with advanced HIV infections.

Cytolytic T lymphocytes play an important role in host defense against viral infections, including human immunodeficiency virus (HIV). In a phase I clinical trial (protocol 080 of the AIDS Clinical Trials Group), generation of CD8+ effector cells from peripheral blood of patients with acquired immunodeficiency syndrome (AIDS)-related complex (ARC) or AIDS and safety of autologous adoptive transfer of these cells were evaluated. For therapeutic infusions, CD8+ T cells were purified by positive selection on anti-CD8 monoclonal antibody-coated flasks from leukapheresed peripheral blood of seven patients. These CD8+ T cells were cultured in the presence of interleukin-2 and phytohemagglutinin for up to 3 weeks to obtain cells sufficient for therapeutic infusions (10(8) to 10(10)). All 31 cell cultures established from the seven patients and used for therapy were highly enriched in CD8+ (mean, 97%), CD8+HLA-DR+ (50%), cytotoxic CD8+CD11b- (82%), and memory CD29+ (78%) T lymphocytes. In vitro expanded CD8+ cells had excellent cytotoxic function at the time they were used for therapy, including HIV-specific activity against autologous targets infected with vaccinia vectors expressing HIV-IIIb antigens, gag, pol, and env. Anti-HIV activity of cultured CD8+ cells was significantly higher than that of autologous fresh peripheral blood lymphocytes. Our results show that CD8+ T lymphocytes obtained from peripheral blood of symptomatic HIV-infected patients can be purified, cultured to obtain large numbers of cells with enhanced anti-HIV activity, and safely infused into patients with AIDS as a form of immunotherapy.

One hundred and twenty-eight patients with non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD), and acute lymphoblastic leukemia (ALL) previously reported from a phase III trial of rhGM-CSF or placebo following autologous bone marrow transplantation (ABMT) were investigated for the development of late toxicities. Median follow-up is 36 months. No apparent long-term deleterious effects on BM function were observed. Moreover, disease-free survival and overall survival were similar for patients on both treatment arms, arguing for the long-term safety of recombinant human granulocyte macrophage-colony-stimulating factor (rhGM-CSF). The only factors predictive for both a high risk of relapse over time and mortality were having the diagnosis of ALL and/or undergoing ABMT in resistant relapse. We attempted to identify clinical variables before BM harvest, at the time of marrow infusion, or events within the first 100 days posttransplant, which might predict speed of neutrophil recovery in the setting of placebo or rhGM-CSF administration after ABMT. Only previous exposure to agents that deplete stem cells led to a significant delay in neutrophil recovery, suggesting their avoidance in patients who may undergo ABMT. Nevertheless, even those patients benefited from rhGM-CSF. For all patients, rhGM-CSF and agents that deplete stem cells were the strongest independent predictors for neutrophil engraftment. With the increasing use of newer hematopoietic growth factors both alone and in combination, long-term follow-up is essential to confirm the same safety that we report with rhGM-CSF.

Non-Hodgkin's lymphoma (NHL) is the most common human immunodeficiency virus (HIV)-associated malignancy in hemophiliacs. We studied the incidence and clinicopathologic features of NHL in 3,041 hemophiliacs followed at 18 US Hemophilia Centers between 1978 and 1989. Of the 1,295 (56.6%) who were HIV(+), 253 (19.5%) developed acquired immunodeficiency syndrome (AIDS), of whom 14 (5.5%) developed NHL. Three NHL occurred in HIV(-) hemophiliacs, for a 36.5-fold greater risk in HIV(+) than HIV(-) hemophiliacs (P < .001). The NHL incidence rate was 29-fold greater than in the US population by Surveillance, Epidemiology, and End Results (SEER) estimates (P < .001). Between 0 and 4 lymphomas have been observed per year between 1978 and 1989. At presentation 13 (92.9%) of the HIV(+) NHL were extranodal. Ten were stage IV, 1 stage II, and 3 stage IE. Ten (71.4%) were high-grade, 3 (21.4%) intermediate-grade, and 1 (7.1%) was a low-grade B-cell lymphoma. Epstein-Barr virus (EBV) DNA was detected in 36% by in situ hybridization, including one central nervous system (CNS) lymphoma. The mean CD4 cell count at NHL diagnosis was 64/mm3, the mean latency from initial HIV infection was estimated to be 59 months, and the median survival was 7 months. The incidence of basal cell carcinoma in HIV(+) hemophiliacs was 18.3-fold greater than in HIV(-) hemophiliacs (P < .001) and 11.4-fold greater than in the US population (P < .001). In conclusion, incidence rates of NHL and basal cell carcinoma in HIV(+) hemophiliacs are significantly increased over rates in HIV(-) hemophiliacs and over rates in the US population. Clinicopathologic presentation of NHL in HIV(+) hemophiliacs is similar to that in HIV(+) homosexual men.

Platelet-derived growth factor (PDGF) is a potent mitogen thought to propagate atherosclerosis and other proliferative or inflammatory diseases. Some of these diseases are ameliorated in humans by ingestion of omega-3 fatty acids. We investigated mRNA expression of both PDGF-A and PDGF-B in quiescent peripheral blood mononuclear cells from healthy male volunteers. For this, a highly sensitive, quantitative polymerase chain reaction strategy (3n-PCR) was developed. In contrast to granulocytes, both PDGF-A and PDGF-B mRNAs are expressed in mononuclear cells. This expression occurs at a remarkably constant rate. Moreover, effects of 7 g/d of a 85% omega-3 fatty acid fish oil concentrate were investigated in a 6-week controlled, randomized, observer-blind study in 14 human volunteers, 7 of whom served as controls. omega-3 Fatty acids increased in mononuclear cell phospholipids. We demonstrate for the first time that diet affects human gene regulation. Dietary omega-3 fatty acids downregulate gene expression of both PDGF-A (-66%), and PDGF-B (-70%). This may represent a novel mechanism for the antifibrotic and antiatherosclerotic action of omega-3 fatty acids.

Interleukin-1 (IL-1) modulation of cytokine receptors (human IL-1 receptor [hIL-1R], human granulocyte colony-stimulating factor [hG-CSFR], human granulocyte-macrophage CSF receptor [hGM-CSFR], and human tumor necrosis factor receptor [hTNFR]) on human neutrophils was studied both in vitro and in vivo. In vitro, incubation of neutrophils with IL-1 at 37 degrees C for 0.5 or 8 hours caused a reduction of IL-1 binding in a dose-dependent manner, but did not demonstrably affect binding of the other cytokines tested. In vivo, neutrophils from patients with gastrointestinal malignancies who were participating in a clinical trial of recombinant human IL-1 beta (rhIL-1 beta) demonstrated modulation of cytokine receptors in an IL-1 beta dose- and time-dependent manner. At the two highest dose levels of IL-1 beta (0.068 and 0.1 microgram/kg), reduction (> 40%) of G-CSF binding and elevation (twofold to sixfold) of IL-1 binding to neutrophils was observed after 1 hour and 4 to 8 hours, respectively. In addition, IL-1 beta rapidly elevated G-CSF and glucocorticoid levels in plasma. Patients at the lowest dose level (0.002 microgram/kg) had a less dramatic change in these parameters. Further in vitro studies showed that synthetic glucocorticoids and G-CSF synergistically up-modulated IL-1 binding to neutrophils in a dose- and time-dependent manner. Scatchard analysis of binding data showed that this in vitro synergistic modulation was due to an increase in receptor numbers, rather than an increase in binding affinity. In addition, both human umbilical cord blood and bone marrow neutrophils responded to G-CSF and dexamethasone (Dex) with a superadditive increase in IL-1 binding. Therefore, one of mechanisms for IL-1 up-modulation of IL-1R on human neutrophils in vivo was due to the fact that IL-1 rapidly elevates serum levels of G-CSF and glucocorticoids.

Three hundred thirty-five previously untreated patients with multiple myeloma in clinical stages II and III entered a randomized trial comparing intermittent oral melphalan and prednisone (MP) therapy (n = 171) with MP in combination with natural (leukocyte-derived) alpha-interferon (MP/IFN) (n = 164). The treatment groups were comparable with regard to major prognostic factors. The response frequency was 42% in the MP group and 68% in the MP/IFN group (P < .0001). Eighty-five percent of IgA myelomas and 71% of Bence-Jones myelomas responded to MP/IFN compared with 48% and 27%, respectively, to MP treatment (P = .001). There was no difference in the overall survival between the two treatment groups. However, the survival of 72 patients with IgA or Bence-Jones myeloma randomized to receive MP/IFN was significantly longer (median 32 months) than that of 71 patients treated with MP (median 17 months) (p < .05). No statistically significant difference in response frequency (60% v 46%) or survival was found for patients with IgG myeloma. Hematologic toxicity, WHO grades III and IV, was higher in the MP/IFN group (48%) than in the MP group (33%) (P < .05) during the induction treatment period. Flulike syndrome was observed in 68% of patients receiving MP/IFN. The results show that MP/IFN is a well-tolerated treatment regimen, superior to MP for remission induction, and it improves significantly the overall survival for patients with IgA and Bence-Jones myelomas.

We treated 23 patients with myelodysplastic syndromes (MDS); 2 refractory anemia (RA) with prior therapy, 11 RA with excess of blasts (RAEB), and 10 RAEB in transformation (RAEB-T), with daily oral 45 mg/m2 all-trans retinoic acid (ATRA) in a multiinstitutional prospective study. In two patients with RAEB and one with RAEB-T, a more than 1,000/microL increase of peripheral neutrophil counts was observed with some reduction of blast percentage in the bone marrow 2 to 9 weeks after the start of ATRA. However, the effect was transient and did not last for more than 5 weeks despite the continuation of ATRA therapy. In one other patient with RA, one patient with RAEB, and one patient with RAEB-T, slight increase of hemoglobin levels or reduction of blast percentage in bone marrow was noted. Toxicities attributable to ATRA were minimal and included cheilitis, xerosis, dermatitis, gastrointestinal disorders, abnormal liver function tests, and high serum triglyceridemia. Although ATRA works remarkably as a differentiation therapy in acute promyelocytic leukemia, its effect in MDS included in this study was modest. Further study of this agent alone or in combination may be warranted in less advanced stages of this disease.

Although high-dose chemotherapy and autologous bone marrow transplantation (ABMT) are increasingly being used for the treatment of relapsed and resistant Hodgkin's disease, there have been few large, single-center studies reported with adequate follow-up to allow full evaluation of this therapeutic modality. We present 155 poor-risk Hodgkin's disease patients who received high-dose BEAM (BCNU, etoposide, cytosine arabinoside, and melphalan) chemotherapy and ABMT who have been studied over a period of 8 years. All patients had either not attained a remission on mechlorethamine, vincristine, procarbazine, prednisone-type therapy and had poor prognostic features at presentation, not attained a complete remission or relapsed within 1 year of an initial alternating regimen, or not attained remission with two or more lines of treatment. At the time of ABMT the relapse status of the patients was as follows: 46 patients were primarily refractory to induction therapy, 7 were good partial responders, 52 were in first relapse, 37 in second relapse, and 13 in third relapse. Seventy-eight patients had chemoresistant disease, 33 had chemosensitive disease at the time of ABMT, and 44 were untested for chemosensitivity at latest relapse. The procedure related mortality in the first 90 days post-ABMT of 10% overall. At 3 months 43 patients (28%) were assessed as complete responders, 72 patients had a partial response (46%), and 24 patients (16%) had no response or progression of disease. However, by 6 months, 53 (24%) patients were assessed as complete responders and 51 (33%) patients had nonprogressive disease. Forty-five patients had received radiotherapy post-ABMT to residual masses (41 patients) or to previous sites of bulk disease (4 patients). The actuarial overall and progression-free survival at 5 years was 55% and 50%, respectively. On multivariate analysis patients with bulk (masses > 10 cm), heavily pretreated patients (those receiving three or more lines of treatment) and females had a significantly poorer prognosis. Relapse status was also significant for progression-free survival in that patients in second (60%) and third relapse (70%) had a better prognosis than those in first relapse (44%) or with primary refractory disease (33%). Response to prior chemotherapy did not predict for progression-free survival. These results enable comparisons to be made between high-dose chemotherapy with ABMT and conventional dose salvage therapy. Furthermore, although the results as a whole are highly encouraging, certain groups carry an unfavorable prognosis.

The purpose of this study was to define, in a phase I study in leukemia, the maximally tolerated dose (MTD), major toxicities, and possible antitumor activity of Topotecan, a new topoisomerase I (topo I) inhibitor. Topotecan was delivered by a 5-day continuous infusion every 3 to 4 weeks to patients with refractory or relapsed acute leukemia, at doses ranging from 3.5 mg/m2 to 18 mg/m2 per course. Twenty-seven patients were treated, including 17 patients with acute myelogenous or undifferentiated leukemia, 7 with acute lymphocytic leukemia, and 3 with chronic myelogenous leukemia in blastic phase. Severe mucositis was the dose-limiting toxicity occurring in two of five patients treated with Topotecan 11.8 mg/m2 per course; a third patient had prolonged myelosuppression. At the MTD of 10 mg/m2 per course, 1 of 12 patients had severe mucositis and 5 had mild-to-moderate mucositis. Nausea, vomiting, diarrhea, and prolonged myelosuppression were uncommon. Three patients (11%) achieved a complete response, two (7%) had a partial response, and one (4%) had a hematologic improvement. The overall complete plus partial response rate was 19%, and 24% in acute myelogenous or undifferentiated leukemia. A novel in vitro assay that quantifies Topotecan-stabilized topo I-DNA complexes in patient samples was used, which demonstrated heterogeneity in the ability of Topotecan to interact with topo I, the intracellular target of Topotecan. This phase I study defined the MTD of Topotecan to be 10 mg/m2 by continuous infusion over 5 days every 3 to 4 weeks in patients with refractory or relapsed acute leukemia. Severe mucositis was the dose-limiting toxicity. Future studies will define the precise activity of Topotecan in different leukemia subsets, its efficacy in combination with other antileukemic drugs, and correlations between Topotecan-induced topo I-DNA complex formation and individual patient response to Topotecan.

The effects of interferon-alpha (IFN-alpha) on clinical and serologic manifestations of mixed cryoglobulinemia (MC) were investigated by randomized, crossover-controlled trial in 26 patients. The trial alternated 6 months with and 6 months without IFN-alpha therapy (2 x 10(6) IU daily for a month, then every other day for 5 months). In 22 patients, pretreatment steroid dosage remained unchanged during the study. Six patients dropped out (three because of side effects), whereas another 20 patients experienced a significant improvement of purpura (P < .02) and serum transaminases (P < .005) during IFN-alpha treatment. The presence of clinical improvement was supported by the outcome measurements of several immunologic parameters. In particular, serum cryoglobulins were significantly reduced (P < .04) during IFN-alpha therapy. A rebound phenomenon of clinical and serologic parameters was observed after IFN-alpha discontinuation. In addition, no variations were recorded during 6 months without therapy. Hepatitis C virus (HCV) RNA was detected in 91% (20/22) of our MC patients; in 2/13 cases HCV RNA was no longer detectable in serum samples after IFN-alpha therapy. Thus, IFN-alpha could be considered as treatment for MC in patients with HCV seropositivity.