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Biomedical subjects

M Abromowitch

Publications and source records attributed to M Abromowitch.

At least 37 records · Page 2Linked to original sources
PubMed1987

Clinical pharmacodynamics of continuous infusion teniposide: systemic exposure as a determinant of response in a phase I trial.

Teniposide (VM-26) is an effective anticancer drug usually administered as a short infusion in doses of 150 to 165 mg/m2. The objectives of the trial reported here were to evaluate clinical responses and assess pharmacokinetic parameters as a determinant of outcome when VM-26 was administered as a 72-hour continuous infusion (CI) with doses escalated from 300 to 750 mg/m2 per course. Twenty-eight patients with recurrent leukemia, lymphoma, or neuroblastoma received 53 courses of CI VM-26 and 16 had measurable responses. There were two partial remissions and one stable disease among seven neuroblastoma patients and 13 of 21 leukemia/lymphoma patients had oncolytic responses (greater than or equal to 75% decrease in circulating blasts). Toxicity included moderate to severe mucositis and myelosuppression. Pharmacokinetic parameters determined during 35 courses administered to 23 patients were highly variable. Clearance (CI) ranged between 3.7 and 43.8 ml/min/m2, resulting in VM-26 plasma concentrations from 2.8 to 30.6 mg/L across all dose levels. The interpatient pharmacokinetic variability reflected in CI and VM-26 steady state concentrations (Css), obscured any dose-response relationship. However, when pharmacokinetic parameters for responding and nonresponding patients were compared, statistically significant relationships were observed. For responders, the mean Css was 15.2 mg/L and mean CI was 12.1 mL/min/m2; for nonresponders, mean Css was 6.2 mg/L (P less than .01) and mean CI was 21.3 mL/min/m2 (P less than .05). Thus, patients with higher CI and lower Css were less likely to respond. Clinical responses occurred in ten of ten patients with Css greater than 12 mg/L, and only five of 13 patients with Css less than 12 mg/L (P less than .01). In this study, interpatient pharmacokinetic variability yielded a four- to sixfold difference in intensity of systemic exposure (Css) within the same dose level, which was an important determinant of clinical response. These data indicate that achieving a VM-26 target concentration for individual patients could ensure an increased intensity of systemic exposure in patients with a high CI and improve the likelihood of effective therapy.

Child↗
PubMed1987

Teniposide plus cytarabine improves outcome in childhood acute lymphoblastic leukemia presenting with a leukocyte count greater than or equal to 100 x 10(9)/L.

Childhood acute lymphoblastic leukemia with an initial leukocyte count greater than or equal to 100 X 10(9)/L responds poorly to conventional chemotherapy. To extend event-free survival (EFS) in this disease, we devised a protocol that specifies intensive 2-week courses of teniposide (VM-26, 165 mg/m2) plus cytarabine (ara-C, 300 mg/m2), before and immediately after standard 4-week remission induction therapy with prednisone, vincristine, and L-asparaginase. The VM-26 and ara-C combination was also administered intermittently for the first year of continuation treatment with oral 6-mercaptopurine and methotrexate. CNS prophylaxis consisted of periodic intrathecal (IT) injections of methotrexate and delayed cranial irradiation. At a median follow-up of 4 years, the estimated EFS rate for 57 consecutive patients with leukocyte counts of 100 to 1,000 X 10(9)/L was 44%, compared with 10% for matched controls (P less than .001). Remission induction rates in the two groups were similar (82% v 72%, P = .16). Twenty-five patients in the VM-26/ara-C group have survived without adverse events for 2.7 to 6.8 years, whereas only nine of the controls achieved more than a year of EFS. The most common complications during early treatment were acute hyperkalemia from rapid tumor cell lysis and infections due to prolonged marrow aplasia. Continuation chemotherapy was well tolerated. We conclude that VM-26 plus ara-C, added to each phase of an otherwise basic regimen of chemotherapy, will substantially improve prognosis in this high-risk form of childhood leukemia.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Clinical and biologic hallmarks of the Philadelphia chromosome in childhood acute lymphoblastic leukemia.

Of 366 children with acute lymphoblastic leukemia (ALL) in whose bone marrow cells complete G-banding of chromosomes was successful, translocations were present at diagnosis in 141 (38.5%). The Philadelphia (Ph) chromosome was identified in 18 of these cases (4.9%). Features closely associated with the presence of the Ph chromosome were older age (median, 7.9 years), high leukocyte count (median, 47.3 X 10(9)/L), French-American-British L1 blast cell morphology, high incidence of CNS leukemia at diagnosis, and the common ALL immunophenotype. All patients were treated according to modern chemotherapeutic regimens for ALL used at our institution. Complete remissions were successfully induced in only 13 (72%) of the 18 patients with Ph + ALL, and only six remain free of leukemia for periods of 7+, 9+, 10+, 13+, 49+, and 70+ months. Our findings confirm the association of the Ph chromosome with classic high-risk features of ALL in children and suggest that this abnormality confers a very poor prognosis that has not yet been improved by modifications in established therapeutic regimens.

Acute Disease↗
PubMed1987

Clinical pharmacodynamic studies of high-dose methotrexate in acute lymphocytic leukemia.

As the intensity of cancer chemotherapy has been reported to influence clinical response for several drug-sensitive cancers, we have investigated the relation between systemic exposure to high-dose methotrexate (HDMTX) and clinical response in childhood acute lymphocytic leukemia (ALL). A total of 108 consecutive, previously untreated children with "standard-intermediate risk" ALL were randomized to receive postinduction therapy with HDMTX (1000 mg/m2 iv over 24 hours weekly for 3 weeks, then every 6 weeks for 72 weeks), superimposed on conventional therapy with low-dose 6-mercaptopurine (6MP; 50 mg/m2 orally per day) and methotrexate (MTX; 25 mg/m2 orally per week). The systemic clearance of HDMTX ranged from 40 to 131 ml/minute/m2 among these patients, yielding MTX steady-state plasma concentrations (Cpss) ranging from 9.3 to 25.4 microM during the infusion. The group of patients (n = 59) with median MTX Cpss less than 16 microM during the HDMTX infusion had a higher probability of having any relapse than patients (n = 49) with MTX Cpss greater than 16 microM (P less than 0.05). In a previously reported univariate analysis, patients with MTX Cpss less than or equal to 16 microM were 3.2 times more likely to relapse on therapy (P = 0.01) and 6.9 times more likely to have a hematologic relapse on therapy (P = 0.001). Multivariate and stepwise Cox's regression analyses indicated that MTX Cpss retains its prognostic importance even when other prognostic variables (i.e., DNA Index, WBC, hemoglobin) are considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1986

Clinical pharmacodynamics of high-dose methotrexate in acute lymphocytic leukemia. Identification of a relation between concentration and effect.

High-dose methotrexate (500 to 33,600 mg per square meter of body-surface area) with leucovorin rescue is a common component of therapy for acute lymphocytic leukemia. To increase understanding of the relation between the serum concentration and the effect of methotrexate, we conducted a randomized, prospective study of 108 children with "standard-risk" acute lymphocytic leukemia who were treated with 15 doses of methotrexate (1000 mg per square meter) that were infused over 24 hours. The median length of follow-up was 3.5 years from diagnosis for patients still in remission. Variability between patients in methotrexate clearance produced steady-state serum concentrations that ranged from 9.3 to 25.4 microM. Patients with median methotrexate concentrations of less than 16 microM (n = 59) had a lower probability of remaining in remission (P less than 0.05) than patients with concentrations of 16 microM or more (n = 49). Multivariate analyses indicated that patients with methotrexate concentrations of less than 16 microM were 3 times more likely to have any kind of relapse during therapy (P = 0.01) and 7 times more likely to have a hematologic relapse during therapy (P = 0.001). Stepwise Cox's regression identified leukemic-cell DNA content, methotrexate concentration, and hemoglobin as significant prognostic variables for hematologic relapse (P = 0.0005). We conclude that there is a concentration-effect relation for high-dose methotrexate in acute lymphocytic leukemia and that 1000 mg per square meter infused over a period of 24 hours may not be optimal for patients with relatively fast drug clearance.

Adolescent↗
PubMed1986

Use of the automatic interaction detector method to identify patient characteristics related to methotrexate clearance.

Systemic methotrexate (MTX) clearance was determined in 108 children who received 15 courses of MTX, 1000 mg/m2 iv over 24 hours, as a component of therapy for acute lymphocytic leukemia. The median MTX clearance was used as the representative value for each patient, and these values ranged from 44.7 to 132.1 ml/min/m2 (X = 78.4 ml/min/m2). The automatic interaction detector approach was used to determine the patient characteristics that correlated with MTX clearance. Characteristics examined were sex, age, estimated creatinine clearance, SGPT, and body surface area. The initial splits were based on creatinine clearance, and mean MTX clearances in three subgroups (50 to 100, 100 to 150, and greater than 150 ml/min/m2) were 73.1, 78.3, and 90.5 ml/min/m2, respectively. For patients with the slowest creatinine clearance, abnormal SGPT concentrations (greater than 35 IU/L) were associated with slower MTX clearance (77.6 vs. 67.8 ml/min/m2). In the latter subgroup, boys had faster clearance than girls (77.4 vs. 60.9 ml/min/m2). These results demonstrate that for children with normal serum creatinine concentrations, interpatient variability in MTX clearance can partly be explained by measures of renal and hepatic function, which indicates that the observed variability in MTX clearance is not totally random.

Adolescent↗
PubMed1986

Results of treatment of advanced-stage Burkitt's lymphoma and B cell (SIg+) acute lymphoblastic leukemia with high-dose fractionated cyclophosphamide and coordinated high-dose methotrexate and cytarabine.

To address the problem of historically poor results in the treatment of children with advanced-stage Burkitt's lymphoma and B cell (SIg+) acute lymphoblastic leukemia (ALL), an intensive chemotherapy regimen was devised using the most effective single agents in high-dose short courses. Treatment commenced with a fractionated schedule of intravenous (IV) cyclophosphamide (300 mg/m2 every 12 hours for six doses) followed immediately by Adriamycin (50 mg/m2) and vincristine (1.5 mg/m2) with combined intrathecal (IT) methotrexate and cytarabine. Predictably, this treatment produced virtually complete disappearance of all tumor and profound myelosuppression. Immediately on hematologic recovery, IV high-dose methotrexate (1,000 mg/m2 over 24 hours) followed by IV cytarabine (400 mg/m2 over the next 48 hours) was administered with leucovorin rescue and repeated IT treatments. The treatment sequence described above is repeated four times, with the dose of cytarabine doubled in succeeding courses, up to 3,200 mg/m2. The entire planned therapy required approximately 24 weeks. Since 1981, we treated a total of 29 children with this approach, 19 of whom had massive unresectable intraabdominal tumor. According to initial extent of disease, 17 were classified as stage III, four as stage IV non-Hodgkin's lymphoma (NHL), and eight as B cell ALL. Eight of the 12 patients with stage IV NHL or B cell ALL had initial involvement of the CNS. Twenty-seven of 29 patients (93%) attained a complete remission. Fourteen of 17 stage III NHL patients remain disease free, for periods ranging from 3+ months to 4 1/2+ years. The actuarial estimate of the proportion of stage III patients remaining disease free at 2 years is 81%. Results in patients with initial involvement of the CNS and/or marrow are much less favorable, with only two of ten patients who attained remission apparently being cured. In addition to stage, the initial serum lactic dehydrogenase (LDH) level emerged as a prognostic indicator, higher levels (over 1,000 IU/L) being associated with the worst prognosis (P less than .05). Major toxicity consisted of severe hematopoietic suppression and febrile episodes associated with neutropenia. We conclude that this treatment is highly effective for advanced-stage Burkitt's tumors in children free of initial CNS involvement.

Actuarial Analysis↗
PubMed1986

Phase I-II study of recombinant alpha-2 interferon against advanced leukemia and lymphoma in children.

Alpha-2 interferon, produced in Escherichia coli using recombinant DNA techniques, was administered to 17 children with refractory acute lymphoblastic leukemia (ALL) in relapse, two children with TdT-positive, Philadelphia chromosome-positive chronic myelocytic leukemia (CML) in blast crisis, and one child with B cell (SIg+) non-Hodgkin's lymphoma (NHL) in a second extramedullary relapse. An initial 2-week intravenous (IV) phase of interferon was followed by a 3-month subcutaneous (SC) maintenance phase if patients had an objective response or disease stabilization without significant bleeding or infectious complications. When interferon dosages were escalated from 3 to 100 X 10(6) U/m2 in the first phase of therapy, there was rapid progression of disease in the first four patients treated, prompting a modification of the treatment plan. The last 16 patients enrolled received fixed dosages of interferon (ie, 10, 20, 30, and 50 X 10(6) U/m2 administered to four subjects each). One child with T cell ALL had an 11-month complete remission; the patient with lymphoma had a dramatic but brief response; three others (one CML and two ALL) showed disease stabilization for 3 to 6 months with a definite oncolytic effect in two of the three patients. The remaining 15 patients had progressive disease within 2 months and were removed from the study. Acute toxicity included a flu-like syndrome in all patients, increased serum transaminase levels in five, seizures in three (two cases temporally related to fever and one to a thrombocytopenic subarachnoid hemorrhage), and prolonged activated partial thromboplastin times in seven. This phase I-II trial of recombinant alpha-2 interferon demonstrated definite activity without dose-limiting toxicity.

Adolescent↗
PubMed1985

Elective testicular biopsy during chemotherapy for childhood leukaemia is of no clinical value.

The clinical value of early detection of testicular leukaemia was assessed by elective wedge biopsy during the 12th or 18th month of therapy in children with acute lymphoblastic leukaemia. Biopsy samples were taken in 106 of 238 consecutively treated boys who attained complete remission; only 1 had occult disease. Samples were also taken in 2 boys with testicular leukaemia at diagnosis as soon as they achieved complete remission, and in 14 others at the end of therapy; none showed evidence of leukaemic infiltration. 13 boys, including the 1 with biopsy-confirmed occult disease, had a testicular relapse; 6 of these patients had had negative biopsy findings 12-28 months before relapse. These results indicate that elective testicular biopsy during therapy for childhood leukaemia is of no benefit clinically. They also suggest that routine use of end-of-therapy testicular biopsy should be re-evaluated, since frequency of testicular relapse is low, therapy is effective, and negative biopsy findings do not preclude eventual relapse.

Adolescent↗
PubMed1985

Chloroacetate esterase positivity in acute lymphoblastic leukemia.

Chloroacetate esterase (CAE) reactivity is associated with acute nonlymphocytic leukemia (ANLL) and, to the author's knowledge, has not been reported in acute lymphoblastic leukemia (ALL). The authors have identified a single patient whose blasts displayed CAE reactivity from a review of 400 newly diagnosed patients with ALL. The diagnosis of ALL in this case was based upon morphologic evaluation (FAB:L1), presence of terminal deoxynucleotidyl transferase (TdT), the absence of reactivity with myeloperoxidase, and the failure of leukemic blasts to mark with a panel of anti-myeloid monoclonal antibodies. Remission was induced promptly with standard ALL therapy. This case demonstrates that punctate CAE positivity rarely can occur in ALL, and, therefore, CAE is not entirely specific for ANLL. The authors conclude that CAE positivity should not be used as a sole criterion to diagnose ANLL in the absence of supporting morphologic, cytochemical, immunocytologic, or clinical information.

Bone Marrow↗
PubMed1985

Unexpectedly severe toxicity from intensive early treatment of childhood lymphoblastic leukemia.

In early 1984, we treated 13 consecutive patients with acute lymphoblastic leukemia (ALL) using an induction regimen of rapidly rotated combinations of prednisone, vincristine, asparaginase, teniposide (VM-26), cytosine arabinoside, and high-dose methotrexate (MTX) followed by leucovorin rescue. The intent of this clinical trial, designated Total Therapy Study XI, is to test the hypothesis that greater initial leukemia cell kill will decrease opportunities for the development of drug-resistant mutants, with resultant improvement in the length of disease-free survival. Five patients experienced life-threatening gastrointestinal toxicity within three weeks of the start of treatment. One died. Three other patients had severe abdominal pain, abdominal distention, diarrhea, and weight loss, but not gastrointestinal bleeding. In the remaining five patients, toxicity was rapidly reversible, and each child was able to complete the planned course of chemotherapy. The study was then amended to switch high-dose MTX from the induction phase to the consolidation phase, allowing at least one week for mucosal recovery. Among the next 28 patients who were treated, none showed evidence of severe gastrointestinal toxicity. Patients now receive high-dose MTX alone as consolidation therapy and are tolerating it adequately. Drug timing should be examined critically when intensified multiple-agent regimens are being devised for initial treatment of ALL.

Adolescent↗
PubMed1985

Clinical relevance of lymphoblast biological features in children with acute lymphoblastic leukemia.

Improvements in therapy for childhood acute lymphoblastic leukemia (ALL) have led us to reevaluate the prognostic significance of lymphoblast characteristics at diagnosis. From application of univariate and multivariate statistical methods, we determined the relationship of five blast cell features to treatment outcome in 250 patients who were enrolled in two clinical trials at this center from May 1979 through April 1982. Karyotype ploidy, lymphoblast morphology, and immunophenotype were each significantly related to prognosis as measured by time to failure, while periodic acid-Schiff reactivity and glucocorticoid receptor number lacked prognostic implication for this patient population. In addition, clinical features of initial WBC count, age, and race were also significant independent variables in predicting treatment response. By multivariate analysis, both ploidy and morphology contributed prognostic information to a clinical model based on WBC count, age, and race. If the model was adjusted for impact of ploidy, however, French-American-British morphology no longer contributed additional prognostic information. Our findings suggest that many traditional biological features used to estimate prognosis in ALL can be discarded in favor of clinical features (leukocyte count, age, and race) and cytogenetics (ploidy) for planning of future clinical trials.

Adolescent↗
PubMed1985

Etoposide (VP-16) with prednisone and vincristine for the treatment of refractory acute lymphoblastic leukemia.

Fifty children with acute lymphoblastic leukemia (ALL) in first to fifth relapse were treated with a three-drug reinduction regimen consisting of prednisone (40 mg/m2/d for seven days), vincristine (1.5 mg/m2 on day 1) and etoposide (VP-16, 250 mg/m2 on days 1 through 3). The intent was to assess the efficacy of VP-16 in an otherwise conventional reinduction plan, especially in patients who had previously received teniposide (VM-26), the close congener of VP-16. Among the 46 patients who received at least two courses of the therapy, 16 (0.34) achieved complete remission. Seven others showed improvement in their bone marrow status. Each child had been heavily pretreated with prednisone and vincristine, and 14 had received VM-26. That seven patients judged to be clinically resistant to VM-26 had complete responses to prednisone-vincristine-VP-16 indicates that prior treatment with one podophyllotoxin derivative does not preclude responses to the other. We are uncertain about the pharmacologic basis of these results but suggest that the increased dosage and more frequent administration of VP-16, relative to that of VM-26, was sufficient to overcome apparent resistance to the latter compound. Remission durations ranged from one to eight months (median, four months), emphasizing the need to devise more effective continuation therapy, including investigational agents such as the epipodophyllotoxins.

Acute Disease↗
PubMed1985

Prognostic importance of blast cell DNA content in childhood acute lymphoblastic leukemia.

Using flow cytometric techniques, we determined the pretreatment distribution of DNA content in propidium iodide-stained leukemic blasts from 205 children with "standard-risk" acute lymphoblastic leukemia (ALL). Risk assignment was based on an initial WBC count less than 100 X 10(9)/L, no thymic mass, no meningeal leukemia, and lymphoblasts lacking sheep erythrocyte receptors or surface immunoglobulin. A single aneuploid leukemic line was detected in 74 cases (36.1%): 70 hyperdiploid and four hypodiploid. For hyperdiploid cases, the DNA index (DI, or ratio of the DNA content of leukemic v normal G0/G1 cells) ranged from 1.06 to 2.0 (median, 1.20). A secondary leukemic line with hyperdiploid cellular DNA content was identified in 21 cases with diploid primary lines. Children whose primary leukemic line showed a DI greater than or equal to 1.16 (n = 57) had significantly better responses to treatment than did those with either a diploid DI (n = 130; P = .002) or values in the range of 1.01 to 1.15 (n = 14; P = .001). The relative risk of failure for hyperdiploid cases with DI greater than or equal to 1.16, corresponding to greater than or equal to 53 chromosomes, was one-third that of the other two groups. Treatment responses of patients with both diploid and hyperdiploid lines were identical to those associated with single diploid lines, but significantly worse than those associated with single hyperdiploid lines with DI greater than or equal to 1.16 (P = .016). The most favorable prognostic variables selected by a Cox proportional hazards model were: DI greater than or equal to 1.16 (P = .001), white race (P = .022), WBC less than or equal to 25 X 10(9)/L (P = .032), age between 2 and 9 years (P = .075), and hemoglobin less than 7.0 g/dL (P = .094). DNA index greater than or equal to 1.16 retained its significant prognostic impact even after adjustment for other variables (P = .001). With the combination of DI greater than or equal to 1.16 and WBC less than or equal to 25 X 10(9)/L, one can identify a group of children with ALL who have a low probability of relapse when treated with current therapy. If they remain disease-free after longer follow-up, it may be advisable to treat them with less intensive, hence less toxic, chemotherapy than patients with higher WBC counts or lower DI values.

Antigens, Neoplasm↗
PubMed1985

A novel treatment of childhood lymphoblastic non-Hodgkin's lymphoma: early and intermittent use of teniposide plus cytarabine.

We treated 24 children and adolescents with stage III or IV lymphoblastic non-Hodgkin's lymphoma, using a protocol designed for patients with poor-prognosis acute lymphoblastic leukemia (ALL). Early therapy consisted of teniposide plus cytarabine administered before and immediately after prednisone, vincristine, and asparaginase. The two-drug combination was also given intermittently with continuous 6-mercaptopurine and methotrexate during the first year of continuation chemotherapy. Periodic intrathecal methotrexate and delayed cranial irradiation were used to prevent central nervous system involvement. Anthracycline compounds, alkylating agents, high-dose methotrexate, and involved-field irradiation were not used in any phase of treatment. Twenty-two (96%) of the 23 evaluable patients achieved complete remission. With a median follow-up of 2 1/2 years, only four patients have relapsed; the remainder have been disease-free for eight months to more than five years. The projected four-year continuous complete remission rate is 73% for all patients and 79% for the 19 with mediastinal involvement at diagnosis. These results demonstrate that use of teniposide plus cytarabine with an otherwise conventional plan of ALL therapy is an effective approach to the treatment of childhood lymphoblastic lymphoma.

Adolescent↗
PubMed1985

Allergic reactions to teniposide in patients with neuroblastoma and lymphoid malignancies.

Acute allergic reactions have been reported in 1%-5% of patients receiving teniposide. In a patient population of 82 children with leukemia and lymphoma, we observed only two acute reactions during the infusion of 1707 doses of teniposide. In contrast, 14 of 105 children with neuroblastoma developed acute allergic reactions during the infusion of 665 doses of teniposide. Four rechallenge doses of the drug were given to patients with neuroblastoma after premedication with antiallergic agents. All four doses resulted in repeat reactions. Our data suggest that children with neuroblastoma have a significantly higher incidence of acute reactions to teniposide than patients with other malignancies (P = 0.008), and that these reactions cannot be prevented by premedication with antiallergic drugs.

Child↗