The small subset of circulating monocytes that express the maturation-associated CD16 antigen has recently been reported to be elevated in patients with bacterial sepsis. We now show that this novel CD16+ monocyte population is also spontaneously expanded in patients with cancer. We studied 14 patients with metastatic gastrointestinal carcinoma enrolled ina clinical trial of recombinant human macrophage colony-stimulating factor (rhMCSF) plus monoclonal antibody D612. We found that before any cytokine treatment, 12 of 14 patients constitutively displayed significant elevations in both the percentage and the absolute number of CD16+ monocytes, as compared with both normal subjects and ill patients with elevated monocyte counts but without malignancy. CD16+ monocytes accounted for 46% +/- 22% of total monocytes in the patients with cancer versus 5% +/- 3% for controls (P < .01). The increase was not attributable to infection or intercurrent illness and appeared to be associated with the underlying malignancy itself. A similar spontaneous elevation of CD16+ monocytes was observed in 35 of 44 additional patients diagnosed with a variety of other solid tumors. When patients with gastrointestinal carcinoma were treated with rhMCSF, there was a marked further increase in the percentage of CD16+ monocytes (to 83% +/- 11%), as well as in the absolute number of CD16+ cells and the level of CD16 antigen expression. In every case, the patients with cancer showed a greater CD16+ monocyte response than the maximal response obtained in normal volunteer subjects treated witha similar regimen of rhMCSF (n = 5, P < .001), suggesting that the presence of malignancy primed patients for enhanced responsiveness to rhMCSF. We hypothesize that spontaneous expansion of the CD16+ monocyte population may represent a novel biologic marker for a widespread and previously unsuspected host immune response to malignancy.

Topotecan [(S)-9-dimethylaminomethyl-10-hydroxycamptothecin hydrochloride; SK&F 104864-A, NSC 609699], a water soluble semisynthetic analogue of the alkaloid camptothecin, is a potent topoisomerase I inhibitor. Here we show that topotecan stabilizes topoisomerase I/DNA cleavable complexes in radiation-resistant human B-lineage acute lymphoblastic leukemia (ALL) cells, causes rapid apoptotic cell death despite high-level expression of bcl-2 protein, and inhibits ALL cell in vitro clonogenic growth in a dose-dependent fashion. Furthermore, topotecan elicited potent antileukemic activity in three different severe combined immunodeficiency (SCID) mouse models of human poor prognosis ALL and markedly improved event-free survival of SCID mice challenged with otherwise fatal doses of human leukemia cells at systemic drug exposure levels that can be easily achieved in children with leukemia.

To evaluate the safety and efficacy of didanosine (ddl) monotherapy and three different combinations of zidovudine (ZDV) and ddl in asymptomatic human immunodeficiency virus-1 (HIV-1) infection, we conducted an open-label, phase I/II study in 126 asymptomatic HIV-1-infected hemophilic and nonhemophilic subjects with a CD4 count of 200 to 500/mm3 stratified for prior zidovudine treatment and baseline CD4 count. Study arms included arm A, low-dose combination (ZDV 150 mg and ddl 134 mg, daily); arm B, moderate-dose combination (ZDV 300 mg and ddI 334 mg, daily); arm C, high-dose combination (ZDV 600 mg and ddl 500 mg, daily), and arm D, ddl monotherapy (ddl 500 mg, daily). Earlier, more frequent hepatotoxicity was experienced by hemophilic subjects (P = .008), but there were no differences in toxicity between treatment arms (P = .51), nor were there any differences in the rate of development of clinical endpoints by treatment (P = .41). Smaller median CD4 increases occurred over the first 12 weeks for arms A and D, 44/mm3 and 42/mm3, than arms B and C, 105/mm3 and 114/mm3, respectively, (P = .015). Hemophilia status (P = .0004) and prior ZDV experience (P = .044) independently predicted weaker CD4 responses during the first 12 weeks of treatment. Using a regression model and adjusting for hemophilia status, prior ZDV treatment, and baseline CD4, there was a significant reduction in quantitative viral load from baseline by week 12 for all treatment arms combined (P = .0001), with significantly lower median percent reduction for arm A (56.3%) than arms B, C, and D (94.6%, 98.5%, and 91.9%, respectively, P = .015). Although greater hepatoxicity and weaker CD4 responses occur in hemophilic subjects, didanosine monotherapy and combination therapy with zidovudine are safe and effective in asymptomatic HIV-1-infected patients.

We explored the ex vivo alteration in the cytokine release of stimulated blood taken from healthy volunteers treated subcutaneously with 480 micrograms granulocyte colony-stimulating factor (G-CSF). In a double-blind, controlled, randomized study with 21 volunteers who received G-CSF once or twice 24 hours apart, we measured lipopolysaccharide (LPS)-inducible release of various cytokines and soluble receptors at different times after treatment. At day 1 after a single dose of G-CSF, mediator release was also initiated with muramyl dipeptide, Staphylococcus aureus enterotoxin A, lipoteichoic acid, streptolysin O, complement factor C5a, phytohemagglutinin, or phorbol myristate acetate. In blood from G-CSF-treated subjects, our major findings were (1) a maximal 12-fold increase in interleukin-1 receptor antagonist (IL-1ra) release and an increase of both the p55 and p75 soluble tumor necrosis factor (TNF) receptors; (2) a reduction in TNF release when using all the various stimuli described except LPS; (3) an increase in G-CSF and, to lesser extent, in IL-6, IL-8, and IL-10 release; and (4) an attenuation of interferon-gamma (IFN-gamma) and granulocyte-macrophage (GM)-CSF release. Our findings demonstrate that the major effect of G-CSF treatment is a change in the responsiveness of blood towards a variety of stimuli, which we interpret as a shift toward an antiinflammatory cytokine response.

Recombinant human interleukin-6 (IL-6) has previously been shown to increase platelet counts in normal and sublethally irradiated mice, dogs, and primates. To assess its tolerance and efficacy in clinical use, we performed a randomized phase Ib study in patients with ovarian carcinoma. IL-6 was administered during an initial 7-day cycle before any chemotherapy. Beginning 7 days later, six cycles of chemotherapy containing carboplatin were administered every 3 weeks. During chemotherapy cycles 2 to 6, IL-6 was administered from day 4 through day 17 at escalating dose levels from 0.5 to 10 micrograms/kg/d. At each level, three patients received IL-6 and one patient received a placebo. During the prechemotherapy cycle of IL-6, a dose-dependent increase in platelet count was observed from day 12 to 15 and was maximal on day 15 (r = .77; P < .01). The median ploidy of bone marrow megakaryocytes shifted from 16 N to 32 N after 7 days of the initial prechemotherapy IL-6 administration. Dose-dependent increases in C-reactive protein (CRP) and fibrinogen levels were observed on day 8 (P < .0001 for both). A significant decrease in hemoglobin level occured rapidly after initiation of IL-6 therapy and was maximal on day 8 (P < .001). When given after chemotherapy, IL-6 accelerated platelet recovery after chemotherapy cycles 2 to 6. Postponements of scheduled chemotherapy due to thrombocytopenia were less frequent in patients treated with IL-6. No difference in either neutrophils or peripheral blood progenitor assays was observed during or after IL-6 treatment. Toxicity of IL-6 appeared mild and was not dose-limiting up to 10 micrograms/kg/d. Systemic symptoms such as fever, headache, and myalgia were the main side effects and were easily relieved by acetaminophen administration. No biologic toxicity was observed. The data indicate that IL-6 is a well-tolerated cytokine and capable of accelerating platelet recovery in patients receiving chemotherapy.

From March 1988 to March 1991, 19 French bone marrow transplant (BMT) centers participated in a prospective randomized trial comparing two conditioning regimens for patients with chronic myeloid leukemia transplanted in first chronic phase with an HLA identical sibling donor. A total of 120 consecutive patients were randomized to receive either 120 mg/kg of cyclophosphamide followed by total body irradiation (CY-TBI; n = 55) or 16 mg/kg of busulfan followed by 120 mg/kg of CY (BU-CY; n = 65). Two different TBI regimens were used. Thirteen patients received a 10-Gy single-dose TBI (SDTBI), and 42 received a fractionated TBI (FTBI). Median time between diagnosis and BMT was 315 days. Overall 5-year actuarial survival was 62.9% (65.8% +/- 12.5% for CY-TBI and 60.6 +/- 11.7% for BU-CY; P = .5), and overall disease-free survival was 55% (51% +/- 14% for CY-TBI and 59.1% +/- 11.8% for BU-CY; P = .75). All patients conditioned with CY-TBI experienced sustained engraftment; in contrast, 4 of 65 patients conditioned with BU-CY rejected the graft (P = .18). There was no significant statistical difference between the two groups regarding transplant-related mortality (29% for CY-TBI and 38% for BU-CY; P = .44). So far, with a median follow up of 42 months, 11 patients have relapsed; 9 relapses occurred after CY-TBI, mostly after FTBI (8 of 9) and 2 after BU-CY (P = .02). The actuarial risk of relapse was 4.4% +/- 6.7% after BU-CY, 11.1% +/- 20.8% after SDTBI, and 31.3% +/- 18.1% after FTBI (P = .039). In addition, independently of the conditioning regimen, the increase of posttransplant immunosuppression in 16 patients with an anti-interleukin-2 receptor monoclonal antibody (MoAb) in addition to a short course of methotrexate and cyclosporine was shown to increase the actuarial risk of relapse (57% +/- 30% with MoAb v 9% +/- 7.3% without MoAb; P = .001). We conclude that BU is an acceptable alternative to TBI for patients with chronic myeloid leukemia in first chronic phase receiving BMT from HLA identical sibling donors. Both BU-CY and CY-TBI regimens gave similar transplant-related mortality, and the antileukemic efficiency of BU-CY regimen was either similar or even higher than that of CY-TBI.

The goal of this phase II multicenter clinical trial was to evaluate a new intensive chemotherapy program for adults with untreated acute lymphoblastic leukemia (ALL) and to examine prospectively the impact of clinical and biologic characteristics on the outcome. One hundred ninety-seven eligible and evaluable patients (16 to 80 years of age; median, 32 years of age) received cyclophosphamide, daunorubicin, vincristine, prednisone, and L-asparaginase; 167 patients (85%) achieved a complete remission (CR), 13 (7%) had refractory disease, and 17 (9%) died during induction. A higher CR rate was observed in younger patients (94% for those < 30 years old, 85% for those 30 to 59 years old, and 39% for those > or = 60 years old, P < .001) and in those who had a mediastinal mass (100%) or blasts with a T-cell immunophenotype. Eighty percent of B-lineage and 97% of T-cell ALL patients achieved a CR (P = .01). The coexpression of myeloid antigens did not affect the response rate or duration. Seventy percent of those with cytogenetic or molecular evidence of the Philadelphia (Ph) chromosome and 84% of those without such evidence achieved a CR (P = .11). Patients in remission received multiagent consolidation treatment, central nervous system prophylaxis, late intensification, and maintenance chemotherapy for a total of 24 months. After a median follow-up time of 43 months, the median survival for all 197 patients is 36 months; the median remission duration for the 167 CR patients is 29 months. Favorable pretreatment characteristics relative to remission duration or survival are younger age, the presence of a mediastinal mass or lymphadenopathy, a white blood cell count (WBC) less than 30,000/microL, L1 morphology, T or TMy immunophenotype, and the absence of the Ph chromosome. The estimates of the proportion surviving at 3 years are 69% for patients less than 30 years old, 39% for those 30 to 59 years old, 89% for those who had a mediastinal mass, 59% with WBC less than 30,000/microL, 63% with L1 morphology, 69% for T or TMy antigen expression, and 62% for those who lack the Ph chromosome. Fifteen patients (8%) had no unfavorable prognostic factors and have an estimated probability of survival at 5 years of 100% (95% confidence interval, 77% to 100%). This intensive chemotherapy regimen produces a high remission rate and a high proportion of durable remissions in adults with ALL.

Relapse is a major cause of treatment failure following allogeneic bone marrow transplantation (BMT) for acute myeloid leukemia (AML). To reduce the risk of relapse following BMT for patients with hematologic malignancy, our group developed a novel preparative regimen which combines high-dose etoposide with cyclophosphamide and total body irradiation (VPCyTBI). We now report the outcome of therapy with VPCyTBI followed by allogeneic BMT for 40 patients with AML in untreated first relapse. With the exception of increased stomatitis, the toxicity of this regimen was similar to that reported by others for CyTBI. Forty-four months after transplant the actuarial probabilities of disease-free survival (DFS), persistent or recurrent leukemia, and transplant related mortality were .29, .44, and .47 respectively. DFS was improved (P < .01) and risk of persistent or recurrent leukemia reduced (P = .005) among patients with significant (grade > or = 2) acute GVHD. Patients with 30% or more blasts on pre-BMT bone marrow examination were not at increased risk for persistent or recurrent leukemia. We conclude that VPCyTBI with allogeneic BMT is effective therapy for AML in untreated first relapse and that a randomized trial comparing this regimen with CyTBI is warranted.

We conducted a multicenter trial of treatment with all-trans retinoic acid (ATRA) for newly diagnosed acute promyelocytic leukemia (APL) in the AML-92 study and compared it with our previous study with standard intensive chemotherapy, the AML-89 study, in the view of complete remission (CR) rate, incidence of early death, and event-free survival (EFS). Patients were scheduled to receive oral ATRA 45 mg/m2 daily until CR. If patients had leukocyte counts above 3 x 10(9)/L at the start of therapy, they received daunorubicine (DNR) 40 mg/m2 for 3 days and behenoyl cytosine arabinoside (BHAC) 200 mg/m2 for 5 days in addition to ATRA. During the ATRA therapy, if patients showed myeloblast plus promyelocyte counts higher than 1 x 10(9)/L in the peripheral blood, they received additional DNR and BHAC in the same schedule, as well. A total of 110 patients were entered into the study. Median age was 43 years (range, 16 to 74). Twenty-eight (26%) of 109 patients (one died before the start of therapy) received ATRA alone. Ninety-seven patients (89%) achieved CR; 48 of 49 (98%) aged less than 40 years, 44 of 52 (84%) aged between 40 and 69, and 5 of 8 (63%) aged above 70 achieved CR, respectively; 25 of 28 (89%) with ATRA alone, 46 of 51 (90%) with ATRA plus initial chemotherapy and 26 of 30 (87%) with ATRA plus later chemotherapy attained CR, respectively. Nine (8%) patients died within 28 days after the start of therapy. In contrast, 44 of 62 patients (71%) attained CR, and 13 (21%) died within 28 days in the AML-89 study with the combination of DNR, BHAC, 6-mercaptopurine and prednisolone. Seven developed retinoic acid syndrome and one died of it in the present study. Other toxicities associated with this drug included cheilitis, desquamation, muscle pain, and hypertriglyceridemia. Predicted 23 months EFS for all ATRA-treated patients and disease-free survival (DFS) in the CR cases were 75% and 81%, respectively, in a median follow-up period of 21 months. Compared to the AML-89 study, there was a highly significant difference in remission rate (P = .004), EFS (P = .0007), and also early mortality rate (P = .02). Present results demonstrated that ATRA with or without chemotherapy gives a statistical improvement in CR rate and early mortality rate, as well as superior survival in newly diagnosed APL.

Patients with severe aplastic anemia (SAA) and a neutrophil (PMN) count of less than 0.5 x 10(9)/L are exposed to a high risk of early mortality when treated with antilymphocyte globulin (ALG) and steroids, with the major problem being infectious complications. The addition of human recombinant granulocyte colony-stimulating factor (rhG-CSF) to ALG may reduce early mortality by improving neutrophil counts in the short term. To test the feasibility of this approach, the SAA Working Party of the European Group for Blood and Marrow Transplantation (EBMT) designed a pilot study that included rhG-CSF (5 micrograms/kg/d, days 1 through 90), horse ALG (HALG; 15 mg/kg/d, days 1 through 5), methylprednisolone (2 mg/kg/d, days 1 through 5, then tapering the dose), and cyclosporin A (CyA; 5 mg/kg/d orally, days 1 through 180). Patients with newly diagnosed acquired SAA (untreated) and with neutrophil counts of < or = 0.5 x 10(9)/L were eligible. Forty consecutive patients entered this study and are evaluable with a minimum follow up of 120 days: the median age was 16 years (range, 2 to 72 years), the interval from diagnosis to treatment was 24 days, and the median PMN count was 0.19 x 10(9)/L. Twenty-one patients had hemorrhages, and 19 were infected at the time of treatment. Overall, treatment was well tolerated: the median maximum PMN count during rhG-CSF administration was 12 x 10(9)/L (range, 0.4 x 10(9)/L to 44 x 10(9)/L). There were three early deaths (8%) due to infection. Four patients (10%) showed no recovery, whereas 33 patients (82%) had trilineage hematologic reconstitution and became transfusion-independent at a median interval of 115 days from treatment. Median follow up for surviving patients is 428 days (range, 122 to 1,005). Actuarial survival is 92%: 86% and 100% for patients with PMN counts less than 0.2 x 10(9)/L or between 0.2 x 10(9)/L and 0.5 x 10(9)/L, respectively. This study suggests that the addition of rhG-CSF to ALG and CyA is well tolerated, is associated with a low risk of mortality, and offers a good chance of hematologic response. This protocol would appear to be an interesting alternative treatment for SAA patients with a low PMN count who lack an HLA-identical sibling.

The administration of low doses of recombinant interleukin-2 (rIL-2) in vivo to patients with malignant neoplasms has been demonstrated to selectively increase the number of circulating natural killer (NK) cells in these patients. Recent evidence from SCID mouse models suggests that IgG subclass levels can be influenced by the presence and activity of NK cells. Therefore, we sought to examine the effect of rIL-2 infusions on human serum IgG subclass concentrations. We determined serum IgG subclass concentrations in 27 cancer patients receiving low-dose rIL-2 by daily continuous intravenous infusion. Eleven of these patients had active, metastatic, nonhematologic tumors; 16 patients had received IL-2 when they were in a minimal residual disease state after autologous or allogeneic bone marrow transplantation. Samples obtained before beginning IL-2 therapy and 8 to 10 weeks into therapy were tested. Treatment with IL-2 resulted in an increase in the percentage of CD56+ NK cells from 18% to 54% (P = .0001). A significant decrease in geometric mean IgG2 concentration from 2,017 micrograms/mL to 1,655 micrograms/mL was noted over this time interval (P = .03). Furthermore, the geometric mean IgG2 concentration after treatment was significantly lower than that of healthy controls (P = .026). In contrast, no significant changes in serum IgG1, IgG3, or IgG4 were noted during r-IL2 infusions. Our data suggest that rIL-2 treatment selectively decreases serum IgG2 concentrations. We speculate that increased NK cells mediate downregulation of human serum IgG2.

Seven of 21 patients with sickle cell anemia developed neurologic complications 5 to 243 days (median, 33 days) after allogeneic marrow transplantation. Among these 7 patients, indications for transplantation included either a past history of stroke (4 patients) or recurrent severe vaso-occlusive events (3 patients). All received marrow from an HLA-identical sibling after preparation with busulfan and cyclophosphamide, and in 4 patients with antithymocyte globulin. Five of 6 patients developing seizures received anticonvulsant and supportive treatment with resolution of neurologic abnormalities. Three patients experienced intracranial bleeding, which was fatal in two. Of the 14 patients free of neurologic complications, 4 patients had experienced stroke before transplantation. However, among all patients with prior stroke, the incidence of intracranial hemorrhage was 38% (3/8), whereas none of the 13 patients without prior stroke developed posttransplant intracranial bleeding (P = .026). We conclude that patients with sickle cell anemia are at increased risk for neurologic complications after marrow ablative therapy and that patients with prior stroke are at increased risk for intracranial hemorrhage. Transplantation of patients before the onset of overt stroke may reduce this risk.

Mice with severe combined immunodeficiency (SCID) provide a model system to examine the in vivo homing, engraftment, and growth patterns of normal and malignant human hematopoietic cells. The relation between leukemic cell growth in this model and the treatment outcome in patients from whom cells were derived has not been established. Leukemic cells from 42 children with newly diagnosed high-risk B-lineage acute lymphoblastic leukemia were inoculated intravenously into CB.17 SCID mice. Mice were killed at 12 weeks or when they became moribund as a result of disseminated leukemia. All mice were necropsied and subjected to a series of laboratory studies to assess their burden of human leukemic cells. Twenty-three patients whose leukemic cells caused histopathologically detectable leukemia in SCID mice had a significantly higher relapse rate than the 19 patients whose leukemic cells did not (estimated 5-year event-free survival: 29.5% v 94.7%; 95% confidence intervals, 11.2% to 50.7% v 68.1% to 99.2%; P < .0001 by log-rank test). The occurrence of overt leukemia in SCID mice was was a highly significant predictor of patient relapse. The estimated instantaneous risk of relapse for patients whose leukemic cells caused overt leukemia in SCID mice was 21.5-fold greater than that for the remaining patients. Thus, growth of human leukemic cells in SCID mice is a strong and independent predictor of relapse in patients with newly diagnosed high-risk B-lineage acute lymphoblastic leukemia.

The effect of priming on occult tumor cell involvement of peripheral blood (PB) and PB progenitor cell (PBPC) collections is poorly characterized. Using sensitive immunocytochemistry (ICC) and tumor clonogenic assays (TCA) specific for epithelial-derived tumor cells, hematopoietic specimens were analyzed for PBPC and occult tumor cell involvement in 28 patients with chemotherapy-sensitive stage IIIB or IV breast cancer. Before PBPC priming, tumor was detected by ICC in PB of 1 of 23 (4%) patients and in bone marrow (BM) harvests of 4 of 27 (15%) patients. Fifteen days after cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF) priming, 2 of 28 (7%) patients had ICC-positive PBPC collections. The median amplification of CD34+ PBPC during this time was over 19-fold (range, < 1 to 199). One patient had pretreatment tumor involvement of both PB and BM. One patient grew tumor colonies in TCA; the PB and BM were ICC- and TCA-positive, but the PBPC collection was ICC-positive and TCA-negative. After cytoreduction with conventional-dose chemotherapy, patients with advanced breast cancer and histologically negative BM biopsy specimens have rare tumor cell involvement of PB and BM. Despite effective PBPC priming with cyclophosphamide and GM-CSF, clonogenic breast cancer cells were not found in the PBPC collection performed on day 15.