Human interferon-inducible protein 10 is a potent inhibitor of angiogenesis in vivo.

Human interferon-inducible protein 10 (IP-10), a member of the alpha chemokine family, inhibits bone marrow colony formation, has antitumor activity in vivo, is chemoattractant for human monocytes and T cells, and promotes T cell adhesion to endothelial cells. Here we report that IP-10 is a potent inhibitor of angiogenesis in vivo. IP-10 profoundly inhibited basic fibroblast growth factor-induced neovascularization of Matrigel (prepared by H. K. Kleinman) injected subcutaneously into athymic mice. In addition, IP-10, in a dose-dependent fashion, suppressed endothelial cell differentiation into tubular capillary structures in vitro. IP-10 had no effect on endothelial cell growth, attachment, and migration as assayed in vitro. These results document an important biological property of IP-10 and raise the possibility that IP-10 may participate in the regulation of angiogenesis during inflammation and tumorigenesis.

T cell receptor alpha-, beta-, and gamma-genes in T cell and pre-B cell acute lymphoblastic leukemia.

We examined alpha-, beta-, and gamma-T cell receptor (TCR) gene activation within acute lymphoblastic leukemias (ALLs) that represent early stages of B and T cell development. We wished to determine if TCR rearrangement and expression was lineage restricted, showed any developmental hierarchy, or could identify new subsets of T cells. Rearrangement of gamma and beta TCR genes occurred early in development but in no set order, and most T-ALLs (22/26) were of sufficient maturity to have rearranged both genes. T-ALLs preferentially rearranged C gamma 2 versus the C gamma 1 complex; no preference within the beta locus was apparent. Once rearranged, the beta TCR continued to be expressed (11/13), whereas the gamma TCR was rarely expressed (3/14). The alpha TCR was expressed only in more mature T-ALLs (8/14) that usually displayed T3. The 3A-1 T cell associated antigen appeared earliest in development followed by T11 and T3. Within pre-B cell ALL a higher incidence of lineage spillover was noted for gamma TCR rearrangements (8/17) than for beta rearrangements (3/17). This also contrasts with the only occasional rearrangement of immunoglobulin (Ig) heavy chains (3/25) in T-ALL. However, in pre-B ALL the pattern of gamma TCR usage was distinct from that of T cells, with the C gamma 1 complex utilized more frequently. Almost all ALLs could be classified as pre-B or T cell in type by combining Ig and TCR genes with monoclonal antibodies recognizing surface antigens, although examples of lineage duality were noted. Unique subpopulations of cells were discovered including two genetically uncommitted ALLs that failed to rearrange either Ig or TCR loci. Moreover, two T lymphoblasts were identified that possessed the T3 molecule but failed to express alpha plus beta TCR genes. These T-ALLs may represent a fortuitous transformation of T cell subsets with alternative T3-Ti complexes.

Absence of hereditary p53 mutations in 10 familial leukemia pedigrees.

Germline p53 mutations have been identified in the Li-Fraumeni syndrome but the role of such mutations in familial leukemia is not established. The p53 gene was examined by single-strand conformation polymorphism analysis of exons 4-8 in 10 families with multiple members affected with leukemia. The diagnoses included acute and chronic leukemias and Hodgkin's disease. Identified in two families were p53 mutations that were nonhereditary. These included a 2-bp deletion in exon 6 found in the lymphoblast DNA of one child whose sibling, cousin, and several adult relatives had acute leukemia. The other nonhereditary p53 mutation was a transition at codon 248 (CGG to CAG, arginine to glutamine) found in the lymphoblasts of a patient with a preleukemic syndrome and acute lymphoblastic leukemia (ALL) whose brother is a long-term survivor of ALL. Thus, p53 mutations were found to occur in two families but both were nonhereditary. Moreover, in the remaining eight families no p53 mutation was identified in the regions of p53 where most mutations have been found in other cancers. Although p53 mutations sometimes may be present, they do not appear to be a primary event responsible for hereditary susceptibility to familial leukemia. This study suggests involvement of other genes or mechanisms.

Hereditary and acquired p53 gene mutations in childhood acute lymphoblastic leukemia.

The p53 gene was examined in primary lymphoblasts of 25 pediatric patients with acute lymphoblastic leukemia by the RNase protection assay and by single strand conformation polymorphism analysis in 23 of 25 cases. p53 mutations were found to occur, but at a low frequency (4 of 25). While all four mutations were identified by single strand conformation polymorphism, the comparative sensitivity of RNase protection was 50% (2 of 4). Heterozygosity was retained at mutated codons in 3 of 4 cases. One pedigree was consistent with the Li-Fraumeni syndrome, and bone marrow from both diagnosis and remission indicated a germline G to T transversion at codon 272 (valine to leucine). Although members of another family were affected with leukemia, a 2-bp deletion in exon 6 was nonhereditary. The other two nonhereditary p53 mutations included a T to G transversion at codon 270 (phenylalanine to cysteine) and a G to C transversion at codon 248 (arginine to proline). These data support the role of both hereditary and acquired p53 mutations in the pathogenesis and/or progression of some cases of childhood acute lymphoblastic leukemia.

Parental alcohol consumption, cigarette smoking, and risk of infant leukemia: a Childrens Cancer Group study.

BACKGROUND: Whether parental drinking and smoking during pregnancy are associated with an increased risk of cancer in offspring is controversial. There are some indications that maternal alcohol consumption is associated with an elevated risk of acute myeloid leukemia (AML) appearing in very young children. Evidence for an association between maternal smoking during pregnancy and risk of leukemia in offspring has been inconsistent. PURPOSE: Using data from a Children's Cancer Group case-control study, we evaluated relationships between infant leukemia risk and parental alcohol consumption and/or cigarette smoking during pregnancy or during the month prior to it. METHODS: Three hundred two leukemia cases (203 acute lymphoid leukemias [ALLs], 88 AMLs, and 11 other leukemia types) diagnosed in children at 18 months of age or younger and 558 individually matched, regional (i.e., same telephone area code and exchange number) controls were included in the analysis. Information concerning parental alcohol consumption and smoking behavior during the index pregnancy and during the month prior to it was collected by telephone interviews with the mothers of all case and control subjects and the fathers of 250 case and 361 control subjects. Odds ratios (ORs) were used to measure the risk of infant leukemia associated with parental smoking and drinking; tests for trend were used to assess dose-response relationships. The data were analyzed further after stratifying the leukemia cases according to histologic and morphologic types. Reported P values are from two-sided tests of statistical significance. RESULTS: Maternal drinking during pregnancy (compared with not drinking) was associated with ORs of 1.43 (95%) confidence interval [CI] = 1.00-2.04) for ALL and 2.64 (95% CI = 1.36-5.06) for AML. A dose-response relationship was observed for total maternal alcohol consumption during pregnancy and risk of AML (P < .01). Alcohol-related risk appeared to be most pronounced for children who developed AML with a morphology of M1 (myeloblastic with minimal maturation) or M2 (myeloblastic with maturation (OR = 7.62; 95% CI = 2.03-28.64). Paternal alcohol consumption did not confer an increased risk of infant leukemia. Maternal smoking during pregnancy (compared with not smoking) was negatively associated with infant leukemia risk (OR = 0.66 and 95% CI = 0.46-0.94 for total leukemia; OR = 0.45 and 95% CI = 0.21-0.96 for AML), whereas paternal smoking 1 month prior to pregnancy (compared with not smoking during the same period) was related to an elevated risk of ALL (OR = 1.56; 95% CI = 1.03-2.36). CONCLUSIONS: Maternal alcohol consumption during pregnancy increases the risk of infant leukemia, especially AML. Maternal smoking, however, does not elevate risk for either AML or ALL. IMPLICATIONS: The data suggest that in utero exposure to alcohol may contribute to leukemogenesis involving myeloid cells.

Breast-feeding and risk of childhood acute leukemia.

BACKGROUND: Breast-feeding is well known to have a protective effect against infection in infants. Although the long-term effects of breast-feeding on childhood cancer have not been studied extensively, a protective effect against childhood Hodgkin's disease and lymphoma has been suggested previously from small investigations. In this study, we tested the hypothesis that breast-feeding decreases the risk of childhood acute leukemia. METHODS: A total of 1744 children with acute lymphoblastic leukemia (ALL) and 1879 matched control subjects, aged 1-14 years, and 456 children with acute myeloid leukemia (AML) and 539 matched control subjects, aged 1-17 years, were included in the analysis. Information regarding breast-feeding was obtained through telephone interviews with mothers. All leukemias combined, histologic type of leukemia (ALL versus AML), immunophenotype of ALL (early pre-B cell, pre-B cell, or T cell), and morphology of AML were assessed separately in the data analysis. RESULTS: Ever having breast-fed was found to be associated with a 21% reduction in risk of childhood acute leukemias (odds ratio [OR] for all types combined = 0.79; 95% confidence interval [CI] = 0.70-0.91). A reduction in risk was seen separately for AML (OR = 0.77; 95% CI = 0.57-1.03) and ALL (OR = 0.80; 95% CI = 0.69-0.93). The inverse associations were stronger with longer duration of breast-feeding for total ALL and AML; for M0, M1, and M2 morphologic subtypes of AML; and for early pre-B-cell ALL. CONCLUSION: In this study, breast-feeding was associated with a reduced risk of childhood acute leukemia. If confirmed in additional epidemiologic studies, our findings suggest that future epidemiologic and experimental efforts should be directed at investigating the anti-infective and/or immune-stimulatory or immune-modulating effects of breast-feeding on leukemogenesis in children.

Bacillus Calmette-Guérin enhancement of colony-stimulating activity and myeloid colony formation following administration of cyclophosphamide.

Pretreatment of mice with Bacillus Calmette-Guérin (BCG) enhances recovery of the peripheral granulocyte count from cyclophosphamide (CTX)-induced leukopenia. In the present study, in vitro bone marrow culture was used to assess the effect of BCG pretreatment on serum levels of myeloid colony-stimulating activity and on regeneration of bone marrow myeloid colony-forming units (CFU-c) following CTX. C57BL/6 mice received either BCG or 0.9% NaCl solution i.p. 8 days prior to the administration of CTX (300 mg/kg i.p.). Following CTX, peak serum levels of myeloid colony-stimulating activity were strikingly higher in the BCG-pretreated mice [1320 +/- 30 (S.E.) units] than in the 0.9% NaCl solution-pretreated mice (764 +/- 37 units). BCG pretreatment also resulted in higher numbers of marrow CFU-c during recovery from CTX (e.g., 43.9 +/- 1.8 versus 20.0 +/- 0.9 myeloid colonies/10(5) marrow cells, Day 3 post-CTX). However, neither the rate of decline nor the absolute nadir of CFU-c, nor CFU-c cell cycle characteristics were affected by the pretreatment. The initial effect of i.p. BCG pretreatment on recovery from CTX-induced granulocytopenia is an augmentation of serum myeloid colony-stimulating activity which precedes the enhanced regeneration of CFU-c and the accelerated recovery of the peripheral granulocyte count.

Anti-GD3 monoclonal antibody analysis of childhood T-cell acute lymphoblastic leukemia: detection of a target antigen for antibody-mediated cytolysis.

We have demonstrated in previous studies significant quantitative differences in the ganglioside content of leukemia cell membranes within immunological subclasses of acute lymphoblastic leukemia (ALL): The disialoganglioside GD3 (disialolactosylceramide) is increased in lymphoblasts with a T-cell immunophenotype compared to non-T-ALL blasts. Utilizing an indirect immunofluorescence assays with a monoclonal antibody to GD3(R24), pretreatment leukemic lymphoblasts from 80 children with ALL were assayed for GD3 expression. GD3 was observed in 75% of leukemic samples in which lymphoblasts exhibited a T-cell phenotype, whereas none of the 33 non-T-ALL samples tested exhibited GD3. Correlation between the expression of GD3 and various antigenic determinants of T-cell differentiation was restricted to CD2; 75% of CD2-negative T-cell ALL blasts failed to express GD3. Anti-GD3 immunoreactivity to T-ALL samples was not restricted to R24 in that two other monoclonal anti-GD3 antibodies were similarly reactive to T-ALL blasts. In vitro incubation of T-cell lymphoblasts with the anti-GD3 antibodies, R24 and C281 and human serum resulted in significant cytotoxicity, and R24 also mediated antibody-dependent cellular cytotoxicity by normal effector cells. Cytotoxicity was specific for those T-ALL blast cell populations which reacted with anti-GD3 as assessed by immunofluorescence microscopy. Since immunoreactivity with monoclonal antibody to GD3 was exclusively observed in a large population of immunophenotypically defined T-cell leukemic lymphoblasts, these studies suggest a possible immunodiagnostic and immunotherapeutic potential for anti-GD3 monoclonal antibodies in T-cell lymphoblastic malignancies.

Expression of GD3 ganglioside in childhood T-cell lymphoblastic malignancies.

Lymphoblasts from seven children with T-cell lymphoblastic malignancies and three children with non-T, non-B acute lymphoblastic leukemia (ALL) were analyzed for ganglioside content. Nonmalignant T-cells from thymus served as controls. Both ganglioside and glycoprotein sialic acid were increased approximately 3-3.5-fold in T-cell disease compared to thymic tissue when expressed on a per cell basis, but not on a per milligram protein basis. Thin-layer chromatography of the isolated ganglioside fraction from T-cell lymphoblasts revealed two major resorcinol-positive bands. One ganglioside comigrated with II3-alpha-N-acetylneuraminosyllactosylceramide (GM3), the major ganglioside in normal lymphoid tissue, and the other ganglioside comigrated with authentic II3-alpha-N-acetylneuraminosyl-alpha 2----8-N-acetylneuraminosyllactosylceramide (GD3) in three different solvent systems. Neuraminidase treatment of the latter ganglioside yielded GM3 and lactosyl ceramide, hydrolysis products of GD3. Scanning densitometry revealed that whereas thymus cells contained 97% GM3 and 3% GD3, T-cell lymphoblasts contained from 22 to 86% GD3 and a corresponding decrease in GM3. The shift to increased GD3 was observed in the blasts from all seven T-cell patients, but not in the blasts from the non-T, non-B patients studied. Only trace quantities of GD3 were detected from two continuous T-ALL cell lines, HSB2 and RPMI 8402. The results demonstrate a consistently significant increase in ganglioside GD3 in uncultured, patient-derived T-cell ALL lymphoblasts when compared to non-T-cell ALL and normal lymphoid tissue. Therefore, GD3 may represent a tumor-associated antigen for the T-cell subclass of childhood lymphoblastic malignancy.

Pharmacology and phase I trial of high-dose oral leucovorin plus 5-fluorouracil in children with refractory cancer: a report from the Children's Cancer Study Group.

Because of the synergy seen in adult trials when 5-fluorouracil is combined with leucovorin, we initiated a Phase I trial of this combination in children's refractory cancer. Leucovorin, an equal mixture of the (6R,S)-diastereoisomers, was administered p.o. for 6 consecutive days as 4 equal doses at 0, 1, 2, and 3 h totaling 500 mg/m2/day. 5-Fluorouracil was given daily on days 2 to 6 as an i.v. bolus immediately following the last dose of leucovorin. The leucovorin dose was held constant while the 5-fluorouracil dose was escalated in cohorts of patients from 300 mg/m2/day to its maximally tolerated dose. Thirty-five patients (19 with acute leukemia and 16 with solid tumors) were evaluable for toxicity. The maximally tolerated dose of FUra was 450 mg/m2/day for 5 treatments for patients with solid tumors and 650 mg/m2/day for 5 treatments for the children with leukemia. The dose-limiting toxicities were myelosuppression and stomatitis. Other side effects included transient, mild elevations of serum transaminases, mild nausea, vomiting, and diarrhea. The pharmacokinetics of high-dose p.o. leucovorin was studied in 23 children. There was considerable interpatient variability in the plasma concentrations of total bioactive folates (TBAF), (6S)-leucovorin, and (6S)-5-methyltetrahydrofolic acid. The maximum plasma concentration (Cmax) of TBAF was 821 +/- 97 (SE) nM, occurring at a median of 8 h; the Cmax of (6S)-leucovorin was 77 +/- 11 nM, occurring at 4 h. The TBAF concentration fell to 146 +/- 42 nM by 24 h. (6S)-5-Methyltetrahydrofolic acid accounted for 90 +/- 7% of the TBAF at the Cmax. The plasma concentration of (6R)-leucovorin, the unnatural isomer, was equal to that of TBAF. Thus, p.o. leucovorin reduced the 5-fold excess of (6R)-leucovorin over TBAF seen after i.v. doses. The relative amounts of the three major plasma species were approximately the same as in adults, even though the Cmax of each compound was lower.

Phase I trial and pharmacokinetic evaluation of fazarabine in children.

A phase I trial of fazarabine (1-beta-D-arabinofuranosyl-5-azacytosine, NSC 281272) administered as a 24-h continuous infusion was performed in 16 children with refractory malignancies. Dose-limiting toxicity consisting of reversible granulocytopenia and thrombocytopenia was observed in 4 of 4 solid tumor patients treated at the starting dose of 20 mg/m2/h. Subsequent patients were treated at a dose of 15 mg/m2/h which was determined to be the maximum tolerated dose. Moderate nausea and vomiting were the only other toxicities observed. Plasma steady-state concentrations of fazarabine were attained by 2-4 h in all patients and were 1.8 and 2.5 microM at the 15- and 20-mg/m2/h doses, respectively. The total body clearance of fazarabine was 571 and 550 ml/min/m2 at the 15- and 20-mg/m2/h doses, respectively. In three of four patients evaluated, fazarabine was detectable in the cerebrospinal fluid (CSF). Steady-state CSF concentrations ranged from 0.29 to 0.74 microM in these three individuals and the steady-state CSF:plasma ratios ranged from 0.22-0.25. Both the plasma and CSF steady-state concentrations were within the 0.1 to 1 microM range reported to be cytotoxic in vitro against the Molt-4 human T-lymphoblastic leukemia cell line. Based on the above, the optimal dose for phase II trials of fazarabine administered as a 24-h infusion is 15 mg/m2/h (360 mg/m2/day).

Phase I and pharmacokinetic evaluation of thiotepa in the cerebrospinal fluid and plasma of pediatric patients: evidence for dose-dependent plasma clearance of thiotepa.

A Phase I trial of thiotepa (TT) administered as an i.v. bolus was performed in 19 children with refractory malignancies. The starting dose was 25 mg/m2 with escalations to 50, 65, and 75 mg/m2. Seven additional patients were treated with 8-h infusions at 50 or 65 mg/m2. The maximum tolerated bolus dose was 65 mg/m2. Reversible myelosuppression was the dose-limiting toxicity. The plasma and cerebrospinal fluid (CSF) pharmacokinetic parameters of TT and its major active metabolite tepa (TP) were also evaluated. When the bolus or infusion methods of TT administration were compared, there was little difference observed in any pharmacokinetic parameter for either TT or TP. The plasma disappearance of TT was rapid and biphasic with half-lives of 0.14 to 0.32 and 1.34 to 2.0 h. Dose-dependent pharmacokinetics was demonstrated by steadily declining plasma clearance with increasing TT dose. Clearance values declined from 28.6 liters/m2/h at the 25-mg/m2 dose to 11.9 liters/m2/h at the 75-mg/m2 dose. The half-life of TP was longer than that of TT and ranged between 4.3 and 5.6 h. There was evidence of the saturation of TP production. TT and TP both exhibited excellent penetration into the CSF, producing lumbar and ventricular concentrations which were nearly identical to simultaneous plasma concentrations. In one patient with a Rickham reservoir, the CSF:plasma area under the (concentration x time) curve ratios for TT and TP were 1.01 and 0.95, respectively. The above data indicate that TT can be safely administered to pediatric patients at doses higher than conventionally used. The favorable CSF penetration of TT and TP suggests that Phase II studies of TT be considered in patients with central nervous system tumors.

Pediatric phase I trial and pharmacokinetic study of trimetrexate.

Trimetrexate, a new nonclassical antifolate, was evaluated in a phase I trial in children with refractory cancer including nine with acute leukemia and 21 with solid tumors. The drug was administered as an i.v. bolus injection weekly for three doses, and courses were repeated every 28 days. The dose ranged from 35 to 145 mg/m2. Thirty patients who received a total of 33 courses were evaluable for toxicity, including 19 who were evaluable for hematological toxicity. The maximally tolerated dose for patients with a solid tumor and leukemia was 110 mg/m2. The dose-limiting toxicities were myelosuppression, mucositis and a pruritic, diffuse maculopapular rash. Other side effects observed included transient, mild elevations of serum transaminases, mild nausea and vomiting, and a local phlebitis at the site of injection at higher dose levels. A single patient with delayed drug clearance had evidence of renal toxicity with a transient increase in serum creatinine. The pharmacokinetics of trimetrexate were studied in 25 patients over the entire dose range. There was considerable interpatient variability in total drug clearance (range 9.2 to 215 ml/min/m2) and half-life (2.1 to 20 h). There was a suggestion of a correlation between plasma concentration at 24 h and the development of hematological toxicity at the highest dose level. Trimetrexate was cleared primarily by biotransformation with renal clearance accounting for only 10% of total clearance. Two metabolites of trimetrexate which inhibit the enzyme dihydrofolate reductase were identified in the urine. One of these appears to be a glucuronide conjugate.

Clinical pharmacology of 9-beta-D-arabinofuranosyladenine in combination with 2'-deoxycoformycin.

It has been suggested that, by inhibiting the adenosine deaminase (ADA)-mediated catabolism of 9-beta-D-arabinofuranosyladenine (ara-A), 2'-deoxycoformycin (DCF) would increase the half-life (t1/2) of ara-A, a compound with known antileukemic activity. To test this hypothesis, we collected serial plasma samples from five patients with refractory acute lymphoblastic leukemia who participated in a Phase I trial of i.v. DCF 915 mg/sq m) in combination with i.v. single-dose ara-A (120-250 mg/sq m). In four of these patients, of whom three were known to have achieved greater than 98% ADA inhibition, a mean ara-A t1/2 of 227 min was achieved. Extrapolated peak levels (i.e., following infusion of ara-A) ranged from 1.5 to 7.4 micrograms/ml (mean, 4.2 micrograms/ml). Elimination of drug appeared to follow a single-compartment model. In two patients who received ara-A without prior DCF and in a third patient who had significant residual ADA activity despite DCF, ara-A was unmeasurable within 5 min of the end of infusion. These data confirm that the kinetics of ara-A catabolism can be altered by inhibition of ADA and suggest that more than one dose of DCF may be necessary for complete inhibition of the enzyme and optimal pharmacological modulation of ara-A.

A pediatric phase I and pharmacokinetic study of spirohydantoin mustard.

A pediatric Phase I and pharmacokinetic study of the lipophilic alkylating agent spirohydantoin mustard (SHM) was conducted in 23 patients. The dose-limiting toxicity of SHM was neurological with disorientation, delirium, or hallucinations occurring in 9 of 23 patients. These symptoms were partially reversible and preventable with physostigmine. In 17 patients who were evaluable for response to treatment (14 of whom had central nervous system malignancies), no objective tumor responses were observed. Pharmacokinetic evaluation of SHM revealed a t1/2 alpha of 1.7 +/- 0.7 min, t1/2 beta of 16 +/- 8.3 min, and total body clearance of 2134 +/- 735 ml/min/m2. Measureable peak plasma levels were less than 40% of that which produces cytotoxicity in vitro against monolayer cultures of rat 9L brain tumor. Over 90% of SHM was protein bound, greatly limiting the free drug available for central nervous system penetration. SHM cerebrospinal fluid to plasma ratios were less than 0.047. The above suggests that in spite of its lipophilicity, SHM may not reach clinically significant levels in the central nervous system at clinically tolerable doses.

Remission induction of meningeal leukemia with high-dose intravenous methotrexate.

Twenty children with acute lymphoblastic leukemia who developed meningeal disease were treated with a high-dose intravenous methotrexate regimen that was designed to achieve and maintain CSF methotrexate concentrations of 10(-5) mol/L without the need for concomitant intrathecal dosing. The methotrexate was administered as a loading dose of 6,000 mg/m2 for a period of one hour followed by an infusion of 1,200 mg/m2/h for 23 hours. Leucovorin rescue was initiated 12 hours after the end of the infusion with a loading dose of 200 mg/m2 followed by 12 mg/m2 every three hours for six doses and then every six hours until the plasma methotrexate level decreased to less than 1 X 10(-7) mol/L. The mean steady-state plasma and CSF methotrexate concentrations achieved were 1.1 X 10(-3) mol/L and 3.6 X 10(-5) mol/L, respectively. All 20 patients responded to this regimen, 16/20 (80%) achieved a complete remission, and 20% obtained a partial remission. The most common toxicities encountered were transient serum transaminase and bilirubin elevations, neutropenia, and mucositis. One patient had focal seizures and transient hemiparesis but recovered completely. High-dose intravenous methotrexate is an effective treatment for the induction of remission after meningeal relapse in acute lymphoblastic leukemia.

Phase I study of chimeric human/murine anti-ganglioside G(D2) monoclonal antibody (ch14.18) with granulocyte-macrophage colony-stimulating factor in children with neuroblastoma immediately after hematopoietic stem-cell transplantation: a Children's Cancer Group Study.

PURPOSE: Ganglioside G(D2) is strongly expressed on the surface of human neuroblastoma cells. It has been shown that the chimeric human/murine anti-G(D2) monoclonal antibody (ch14.18) can induce lysis of neuroblastoma cells by antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. The purposes of the study were (1) to determine the maximum-tolerated dose (MTD) of ch14.18 in combination with standard dose granulocyte-macrophage colony-stimulating factor (GM-CSF) for patients with neuroblastoma who recently completed hematopoietic stem-cell transplantation (HSCT), and (2) to determine the toxicities of ch14.18 with GM-CSF in this setting. PATIENTS AND METHODS: Patients became eligible when the total absolute phagocyte count (APC) was greater than 1, 000/microL after HSCT. ch14.18 was infused intravenously over 5 hours daily for 4 consecutive days. Patients received GM-CSF 250 microg/m(2)/d starting at least 3 days before ch14.18 and continued for 3 days after the completion of ch14.18. The ch14.18 dose levels were 20, 30, 40, and 50 mg/m(2)/d. In the absence of progressive disease, patients were allowed to receive up to six 4-day courses of ch14.18 therapy with GM-CSF. Nineteen patients with neuroblastoma were treated. RESULTS: A total of 79 courses were administered. No toxic deaths occurred. The main toxicities were severe neuropathic pain, fever, nausea/vomiting, urticaria, hypotension, mild to moderate capillary leak syndrome, and neurotoxicity. Three dose-limiting toxicities were observed among six patients at 50 mg/m(2)/d: intractable neuropathic pain, grade 3 recurrent urticaria, and grade 4 vomiting. Human antichimeric antibody developed in 28% of patients. CONCLUSION: ch14.18 can be administered with GM-CSF after HSCT in patients with neuroblastoma with manageable toxicities. The MTD is 40 mg/m(2)/d for 4 days when given in this schedule with GM-CSF.

Recombinant urate oxidase for the prophylaxis or treatment of hyperuricemia in patients With leukemia or lymphoma.

PURPOSE: To improve the control of hyperuricemia in patients with leukemia or lymphoma, we tested a newly developed uricolytic agent, recombinant urate oxidase (SR29142; Rasburicase; Sanofi-Synthelabo, Inc, Paris, France), which catalyzes the oxidation of uric acid to allantoin, a highly water-soluble metabolite readily excreted by the kidneys. PATIENTS AND METHODS: We administered Rasburicase intravenously, at 0.15 or 0.20 mg/kg, for 5 to 7 consecutive days to 131 children, adolescents, and young adults with newly diagnosed leukemia or lymphoma, who either presented with abnormally high plasma uric acid concentrations or had large tumor cell burdens. Blood levels of uric acid, creatinine, phosphorus, and potassium were measured daily. The pharmacokinetics of Rasburicase, the urinary excretion rate of allantoin, and antibodies to Rasburicase were also studied. RESULTS: At either dosage, the recombinant enzyme produced a rapid and sharp decrease in plasma uric acid concentrations in all patients. The median level decreased by 4 hours after treatment, from 9.7 to 1 mg/dL (P =.0001), in the 65 patients who presented with hyperuricemia, and from 4.3 to 0.5 mg/dL (P =.0001) in the remaining 66 patients. Despite cytoreductive chemotherapy, plasma uric acid concentrations remained low throughout the treatment (daily median level, 0.5 mg/dL). The urinary excretion rate of allantoin increased during Rasburicase treatment, peaking on day 3. Serum phosphorus concentrations did not change significantly during the first 3 days of treatment, decreased significantly by day 4 in patients presenting with hyperuricemia (P =.0003), and fell within the normal range in all patients by 48 hours after treatment. Serum creatinine levels decreased significantly after 1 day of treatment in patients with or without hyperuricemia at diagnosis (P =.0003 and P =.02, respectively) and returned to normal range in all patients by day 6 of treatment. Toxicity was negligible, and none of the patients required dialysis. The mean plasma half-lives of the agent were 16.0 +/- 6.3 (SD) hours and 21.1 +/- 12.0 hours, respectively, in patients treated at dosages of 0.15 or 0.20 mg/kg. Seventeen of the 121 assessable patients developed antibodies to the enzyme. CONCLUSION: Rasburicase is safe and highly effective for the prophylaxis or treatment of hyperuricemia in patients with leukemia or lymphoma.

Pharmacokinetics of subcutaneous methotrexate.

The pharmacokinetics of subcutaneously administered methotrexate was studied as a parenteral alternative to oral administration. An initial feasibility study was performed in Rhesus monkeys comparing the subcutaneous route to intravenous (IV) injection and oral administration. The subcutaneous dose was completely absorbed and a sustained-release effect was observed when compared with the IV dose. No local or systemic toxicities resulted from subcutaneous methotrexate in the animals. Twelve children with acute lymphoblastic leukemia on maintenance therapy protocols prescribing either 7.5 mg/m2 biweekly or 40 mg/m2 weekly were also monitored after both a subcutaneous and an oral dose of methotrexate. Four children at the higher dosage level were also studied after an equal IV dose. The subcutaneous dose was again completely absorbed in these children at both dose levels, whereas the oral dose, which produced comparable plasma drug concentrations at the lower dosage level, resulted in a total drug exposure (area under the plasma concentration-time curve) that was one third that of the equal subcutaneous dose at the higher dosage level. No local or systemic toxicity was attributed to the subcutaneous methotrexate. Subcutaneous administration of methotrexate is well tolerated and well absorbed and appears to overcome the problems associated with oral administration, including variable absorption and saturation of the absorption mechanism with increasing doses.

The effect of initial management of hyperleukocytosis on early complications and outcome of children with acute lymphoblastic leukemia.

Data were collected from 124 patients with newly diagnosed acute lymphoblastic leukemia (ALL) and WBC greater than 200,000/microL seen at institutions affiliated with the Children's Cancer Study Group (CCSG) from April 1981 to May 1983. The presenting characteristics, initial management, early complications, and outcome were reviewed. All the children received vigorous intravenous (IV) hydration, alkalinization of the urine, and allopurinol. Thirty-two patients were started on full therapy with no additional measure. One or more special measures believed to reduce the complications of leukostasis and blast cell lysis were administered to 92 patients as follows: small initial doses of prednisone, 63; emergency cranial irradiation, 26; exchange transfusion, 21; and leukopheresis, 19. The incidence of CNS hemorrhage was only 3% (4/124). Seven patients expired during induction and four failed to achieve a remission by day 28. Nineteen patients (15%) had documented bacterial or fungal sepsis. Mild to moderate electrolyte abnormalities occurred in 29 patients: three patients required renal dialysis. Pretreatment with small doses of prednisone did not decrease the incidence of electrolyte abnormalities in those patients when compared with patients who received full chemotherapy. The event-free survival (EFS) for the 106 patients treated on one of the three intensive pilot studies is 55% at 36 months. On multivariate analysis the two significant adverse prognostic factors were massive splenomegaly (P = .02) and WBC count greater than 600,000/microL (P = .05). In conclusion, in patients with hyperleukocytosis the complications of blast cell lysis and leukostasis were manageable with acceptable morbidity and minimal mortality in a group of patients treated with vigorous hydration, allopurinol, and alkalinization of the urine before beginning chemotherapy. Selected patients with severe hyperuricemia and renal dysfunction may benefit from leukopheresis. No beneficial role was demonstrated for the use of small initial doses of prednisone or emergency cranial irradiation.