Phase I study of gemcitabine (difluorodeoxycytidine) in children with relapsed or refractory leukemia (CCG-0955): a report from the Children's Cancer Group.

To determine the maximum tolerated dose (MTD) and assess the toxicity profile and pharmacokinetics of weekly gemcitabine infusions in pediatric patients with refractory hematologic malignancies. Fourteen patients under 21 years old were given infusions of gemcitabine for escalating durations at 10 mg/m2/min weekly for three consecutive weeks. Two males and two females were studied at each dose level. Pharmacokinetics of the drug's metabolism were measured by high pressure-liquid chromatography (HPLC) for 24 h after the first dose. Intracellular difluorodeoxycytidine triphosphate formation in leukemic blasts was measured in selected patients. The MTD of gemcitabine in these patients was 3600 mg/m2/week for three consecutive weeks (10 mg/m2/min for 360 min). Hepatotoxicity was the dose limiting toxicity. Thirty to fifty percent of patients exhibited fever, rash, or myalgia. Rare instances of hypotension and pulmonary toxicity were observed. Two of six patients [one acute lymphoblastic leukemia (ALL) and one acute myelogenous leukemia (AML)] treated at the MTD had at least M2 marrows, although peripheral blood counts did not recover sufficiently for the patients to be considered in complete response. Pharmacokinetics of gemcitabine fit a two-compartment open model with terminal half-life and plasma clearance value of 62 min and 2.2 l/min/m2, respectively. No gender differences were observed. In conclusion, the MTD of gemcitabine was 10 mg/m2/min for 360 min every week for 3 weeks. This is the recommended phase II dose schedule for children with leukemia. The activity of the drug at this schedule in heavily pretreated, refractory patients warrants a phase II trial in hematologic malignancies.

High-dose melphalan, etoposide, total-body irradiation, and autologous stem-cell reconstitution as consolidation therapy for high-risk Ewing's sarcoma does not improve prognosis.

PURPOSE: To determine whether consolidation therapy with high-dose melphalan, etoposide, and total-body irradiation (TBI) with autologous stem-cell support would improve the prognosis for patients with newly diagnosed metastatic Ewing's sarcoma (ES). PATIENTS AND METHODS: Thirty-two eligible patients with newly diagnosed ES metastatic to bone and/or bone marrow were enrolled onto this study. Treatment was initially comprised of five cycles of induction chemotherapy (cyclophosphamide, doxorubicin, and vincristine alternating with ifosfamide and etoposide) and local control. Peripheral-blood stem-cell collection was performed after the second cycle of chemotherapy, with delay if the bone marrow was persistently involved. If patients had a good response to initial therapy, they proceeded to consolidation therapy with melphalan, etoposide, TBI, and stem-cell support. RESULTS: Of the 32 eligible patients, 23 proceeded to high-dose therapy consolidation. Of the nine patients who did not proceed to consolidation, four were secondary to progressive disease and two were secondary to toxicity. Three patients died from toxicity during the high-dose phase of the therapy. The majority of the patients who underwent high-dose consolidation therapy experienced relapse and died with progressive disease. Two-year event-free survival (EFS) for all eligible patients is 20%. The 2-year post-stem-cell reconstitution EFS for the subset of 23 patients who received consolidation therapy is 24%. Analysis of peripheral-blood stem-cell collections by molecular techniques for minimal residual disease showed contamination of at least some samples by tumor cells in all three patients with available data. CONCLUSION: Consolidation with high-dose melphalan, etoposide, TBI, and autologous stem-cell support failed to improve the probability of EFS in this cohort of patients with newly diagnosed metastatic ES.

Phase I study of CI-958 in children and adolescents with recurrent solid tumors.

BACKGROUND: CI-958 is a synthetic intercalating agent of a new chemical class, the benzopyranoindazoles, with promising preclinical activity. Its mechanism of action is thought to be stabilization of the cleavable complex of DNA with topoisomerase II, as well as DNA helicase blockade. It is thought to have less cardiotoxicity than the anthracyclines. Early Phase I studies in adults showed the drug to be well tolerated, making it an attractive agent to pursue in Phase I clinical trials in children. METHODS: Children and adolescents with recurrent solid tumors received CI-958 at an initial dose of 450 mg/m(2) over 2 hours. Dose escalation was performed in a standard fashion in cohorts of three patients until dose limiting toxicity and the maximum tolerated dose were determined. RESULTS: Twenty-one patients were entered on the study. The maximum tolerated dose was found to be 650 mg/m(2). Dose limiting toxicities were Grade 4 neutropenia and Grade 4 hypotension at the dose level of 700 mg/m(2). CONCLUSIONS: The maximum tolerated dose of CI-958 in children and adolescents is 650 mg/m(2). No antitumor activity has been observed.

Prospective randomized trial between two doses of granulocyte colony-stimulating factor after ifosfamide, carboplatin, and etoposide in children with recurrent or refractory solid tumors: a children's cancer group report.

PURPOSE: The objectives of this study were: 1) to compare the time to hematologic recovery (absolute neutrophil count [ANC] > or = 1,000/mm3 and platelet count > or = 100,000/mm3) in a randomized prospective study of two doses of granulocyte colony-stimulating factor (G-CSF) (5.0 vs. 10.0 microg/kg per day) after ifosfamide, carboplatin, and etoposide (ICE) chemotherapy; and 2) to determine the response rate (complete response [CR] + partial response [PR]) of ICE in children with refractory or recurrent solid tumors. PATIENTS AND METHODS: From June 1992 until November 1994, 123 patients with recurrent or refractory pediatric solid tumors were treated with ifosfamide (1,800 mg/m2 per day x 5), carboplatin (400 mg/m2 per day x 2), and etoposide (100 mg/m2 per day x 5) and randomized to receive either 5.0 microg/kg per day or 10.0 microg/kg per day of G-CSF subcutaneously until recovery of ANC to > or = 1,000/mm3. RESULTS: The incidence of grade 4 neutropenia during the first course was 88%. Median time from the start of chemotherapy to ANC > or = 1,000/mm(-3) for all patients during courses 1 and 2 was 21 and 19 days, respectively. The incidence of developing platelet count < or = 20,000/mm3 during course 1 was 82%. The median time from the start of the course of chemotherapy to platelet recovery > or =100,000/mm3 for all patients during courses 1 and 2 was 27 days. There was no significant difference in the median time of ANC recovery, platelet recovery, or incidence of grade 4 neutropenia; and in the median days of fever and the incidence of infections requiring hospitalization and intravenous antibiotics during courses 1 and 2, there was no significant difference between the two doses of G-CSF. One hundred eighteen patients were evaluated for response to ICE. The overall response rate (CR + PR) in this study was 51% (90% confidence interval, 43%-59%). The CR rate for all diagnostic categories was 27%. The Kaplan-Meier estimates of 1-year and 2-year survival probabilities for all patients were 52% and 30%, respectively. CONCLUSION: In summary, this combination of chemotherapy (ICE) was associated with a high CR rate (27%) in children with recurrent or refractory solid tumors, but also with a high incidence of grade 4 neutropenia and thrombocytopenia. Doubling the dose of G-CSF from 5.0 to 10.0 microg/kg per day after ICE chemotherapy did not result in an enhancement of neutrophil or platelet recovery or the incidence of grade 4 neutropenia developing.

A phase I clinical, pharmacological, and biological trial of interleukin 6 plus granulocyte-colony stimulating factor after ifosfamide, carboplatin, and etoposide in children with recurrent/refractory solid tumors: enhanced hematological responses but a high incidence of grade III/IV constitutional toxicities.

A Phase I trial was conducted to determine the safety, biological activity, and hematopoietic recovery by the combination of interleukin 6 (IL-6) and granulocyte-colony stimulating factor (G-CSF) after myelosuppressive chemotherapy in children. Patients <22 years of age at diagnosis with either recurrent or refractory solid tumors received ifosfamide 1,800 mg/m2/day x 5 days, carboplatin 400 mg/m2/ day x 2 days, and etoposide 100 mg/m2/day x 5 days, followed by daily s.c. G-CSF (5 microg/kg/day) and IL-6 (2.5, 3.75, or 5.0 microg/kg/day). Pharmacokinetic, proinflammatory mediator levels, hematopoietic colony assays, and cytokine receptor expression studies were performed during course one. Nineteen patients were evaluable for toxicity and received IL-6 at doses of 2.5 (n = 8), 3.75 (n = 5), or 5.0 (n = 6) microg/kg/day. Dose-limiting constitutional toxicity occurred in two of six patients at 5.0 microg/kg/day, two of five patients at 3.75 microg/kg/day, and two of eight patients at 2.5 microg/kg/day. The maximum tolerated dose (MTD) exceeded the lowest dose tested. Because of lack of drug availability, an MTD was not established. The maximum concentration of IL-6 (2.5 microg/kg/day) was 0.799 +/- 1.055 ng/ml (mean +/- SD). During the first course, the median time to absolute neutrophil count > or = 1,000/mm3 and platelets > or = 100,000 mm3 was estimated at 19 and 23 days, respectively. Peripheral blood progenitor cells expressing receptors to IL-3, IL-6, and G-CSF increased significantly over baseline (P < 0.05). After the first dose of IL-6, IFN-gamma levels were abnormal in 13 patients, and IL-1beta levels were abnormal in 10 patients. IL-6 has a high incidence of constitutional toxicity and a lower MTD in children compared with adults. In vivo use of IL-6 in children after chemotherapy remains limited. However, IL-6 may be more optimally investigated in children under ex vivo conditions.

Phase I trial of anti-B4-blocked ricin in pediatric patients with leukemia and lymphoma.

Monoclonal antibodies, specific for antigens expressed on lymphoid malignancies, which have been conjugated to toxins such as ricin, hold promise in the therapy of childhood leukemia and lymphoma. Anti-B4-blocked ricin (anti-B4-bR) is such an agent, and a phase I study of this agent was conducted in children with relapsed or refractory B-lineage leukemia and lymphoma. Anti-B4-bR was given as two 7-day continuous infusions separated by 7 days. Twenty patients were enrolled and 19 received the drug. Two dosage levels (30 and 40 microg/kg per day) were evaluated. Forty micrograms per kilogram per day was the maximally tolerated dose. Dose-limiting toxicity was capillary leak syndrome. Grade 3 reversible elevation in transaminases was also encountered. Human antimouse antibodies or human antiricin antibodies were detected in five patients. No complete remissions or partial remissions were seen.

Randomized comparison of cisplatin/vincristine/fluorouracil and cisplatin/continuous infusion doxorubicin for treatment of pediatric hepatoblastoma: A report from the Children's Cancer Group and the Pediatric Oncology Group.

PURPOSE: Previous studies demonstrated that chemotherapy with either cisplatin, vincristine, and fluorouracil (regimen A) or cisplatin and continuous infusion doxorubicin (regimen B) improved survival in children with hepatoblastoma. The current trial is a randomized comparison of these two regimens. PATIENTS AND METHODS: Patients (N = 182) were enrolled onto study between August 1989 and December 1992. After initial surgery, patients with stage I-unfavorable histology (UH; n = 43), stage II (n = 7), stage III (n = 83), and stage IV (n = 40) hepatoblastoma were randomized to receive regimen A (n = 92) or regimen B (n = 81). Patients with stage I-favorable histology (FH; n = 9) were treated with four cycles of doxorubicin alone. RESULTS: There were no events among patients with stage I-FH disease. Five-year event-free survival (EFS) estimates were 57% (SD = 5%) and 69% (SD = 5%) for patients on regimens A and B, respectively (P =.09) with a relative risk of 1.54 (95% confidence interval, 0.93 to 2.5) for regimen A versus B. Toxicities were more frequent on regimen B. Patients with stage I-UH, stage II, stage III, or stage IV disease had 5-year EFS estimates of 91% (SD = 4%), 100%, 64% (SD = 5%), and 25% (SD = 7%), respectively. Outcome was similar for either regimen within disease stages. At postinduction surgery I, patients with stage III or IV disease who were found to be tumor-free had no events; those who had complete resections achieved a 5-year EFS of 83% (SD = 6%); other patients with stage III or IV disease had worse outcome. CONCLUSION: Treatment outcome was not significantly different between regimen A and regimen B. Excellent outcome was achieved for patients with stage I-UH and stage II hepatoblastoma and for subsets of patients with stage III disease. New treatment strategies are needed for the majority of patients with advanced-stage hepatoblastoma.

Children's cancer group trials of interleukin-2 therapy to prevent relapse of acute myelogenous leukemia.

PURPOSE: Up to 80% of children with acute myelogenous leukemia treated with intensive chemotherapy achieve remission; however, a large proportion of patients develops recurrent disease. Because interleukin (IL)-2 can induce remission in patients with overt evidence of acute myelogenous leukemia, we hypothesized that it might prevent relapse when administered to patients in first remission after intensive consolidation chemotherapy. A pilot Children's Cancer Group (CCG) trial (CCG-0941) demonstrated the feasibility of this approach, and we initiated a prospective randomized trial (CCG-2961) to further evaluate the safety and potential efficacy of IL-2 therapy in preventing relapse of acute myelogenous leukemia. PATIENTS AND METHODS: In trial CCG-0941, 21 pediatric patients in complete remission following induction and consolidation chemotherapy on protocol CCG-2941 received IL-2 therapy. In CCG-2961, 79 patients in complete remission were randomized as of February 1999 to receive either IL-2 (n = 39) or no further therapy. In both trials, recombinant IL-2 was given at a dose of 9 million IU/m2/d by continuous intravenous infusion for 4 days. After 4 days of rest, IL-2 was resumed at a dose of 1.6 million IU/m2/d for 10 days by continuous infusion. We monitored patients for toxicity and relapse. RESULTS: The majority of patients treated with IL-2 in these two trials experienced some degree of fever. Seven of 60 patients (12%) had clinically significant rashes, and grade 3 vascular leak syndrome and hypotension have each been observed in five patients (8%). Hypotension resolved promptly after treatment with intravenous fluids. No patients have experienced renal toxicity or required cardiac vasopressors or transfer to an intensive care unit; there have been no treatment-related deaths. Overall, the incidence and severity of adverse events remain similar in the two trials. Total projected accrual to the IL-2 randomization is anticipated to be 326 patients, and relapse and survival data remain blinded. CONCLUSION: The dose and schedule of IL-2 used in these two trials continue to be reasonably well tolerated by children with acute myelogenous leukemia in first remission. Any conclusions with regard to efficacy must await completion of the randomized trial.

Association of chromosome arm 9p abnormalities with adverse risk in childhood acute lymphoblastic leukemia: A report from the Children's Cancer Group.

Cytogenetic abnormalities of chromosome arm 9p occur frequently in children with acute lymphoblastic leukemia (ALL). We analyzed 201 such cases (11%) in 1,839 children with newly diagnosed ALL treated between 1989 and 1995 on risk-adjusted protocols of the Children's Cancer Group (CCG). The majority of patients (131; 65%) with a 9p abnormality were classified as higher risk. Nearly all patients had complex karyotypes; most cases had deletions of 9p, add/der(9p), a dicentric involving chromosome arm 9p, and/or balanced translocations and inversions involving 9p. Event-free survival (EFS) estimates at 6 years for patients with and without a 9p aberration were 61% (standard deviation [SD] = 5%) and 76% (SD = 2%; P <.0001). In addition, patients with a 9p abnormality had an increased cumulative incidence of both marrow (P =.04) and central nervous system (P =.0001) relapses. Overall survival also was significantly worse for patients with an abnormal 9p (P <.0001). These effects were most pronounced in standard-risk patients (age 1 to 9 years with white blood cell count <50,000/microL): 6-year EFS of 61% (SD = 9%) versus 80% (SD = 2%; P <.0001). Also, a 9p aberration was an adverse risk factor for B-lineage, but not T-lineage patients. The effect of 9p status on EFS was attenuated, but maintained in a multivariate analysis of EFS after adjustment for Philadelphia chromosome status, age, white blood cell (WBC) count, sex, race, and ploidy group (P =.01). Thus, abnormalities of chromosome arm 9p identify a subgroup of standard-risk patients with increased risk of treatment failure.

Phase I study of temozolomide in children and adolescents with recurrent solid tumors: a report from the Children's Cancer Group.

PURPOSE: The Children's Cancer Group conducted a phase I trial of temozolomide stratified by prior craniospinal irradiation (CSI). PATIENTS AND METHODS: Children and adolescents with recurrent or progressive cancer were enrolled. Temozolomide was administered orally daily for 5 days, with subsequent courses administered every 21 to 28 days after full hematologic recovery. Dose levels tested included 100, 150, 180, 215, 245, and 260 mg/m2 daily. RESULTS: Twenty-seven patients on the non-CSI stratum were assessable for hematologic toxicity. During the first three dose levels (100, 150, and 180 mg/m2 daily), only grades 1 and 2 hematologic toxicity occurred. One patient at 215 mg/m2 daily had grade 3 hematologic toxicity. Three of eight patients (38%) treated at 245 to 260 mg/m2 daily had dose-limiting toxicity (DLT), which included both neutropenia and thrombocytopenia. Twenty-two patients on the CSI stratum were assessable for hematologic toxicity. Hematologic DLT occurred in one of six patients (17%) at 100 mg/m2 daily and in two of four patients (50%) at 215 mg/m2 daily. No nonhematologic DLT occurred; nausea and vomiting occurred in more than half of the patients. After two courses of temozolomide, 10 patients had stable disease (SD), and three patients had a partial response (PR), one of whom subsequently had a complete response (CR) that persists through 24 months of follow-up. CONCLUSION: The maximum-tolerated dose (MTD) of temozolomide for children and adolescents without prior CSI is 215 mg/m2 daily and for those with prior CSI is 180 mg/m2 daily for 5 days, with subsequent courses that begin on day 28. Temozolomide is well tolerated and should undergo phase II testing in children and adolescents.

A Phase II clinical trial of idarubicin administered to children with relapsed brain tumors.

BACKGROUND: Idarubicin (IDR), an anthracycline that is a derivative of daunorubicin, was synthesized in an attempt to find new analogs of daunorubicin with an improved spectrum of activity and diminished acute or chronic toxicity. Because of the favorable pharmacokinetic profile of IDR (with the persistence of its active metabolite [idarubicinol], the penetration of idarubicinol into the cerebrospinal fluid, and the lipophilicity of IDR/idarubicinol compared with other anthracyclines), its more favorable therapeutic index regarding cardiotoxicity in animals, and its potential for oral administration, a Phase II trial of IDR in children with relapsed brain tumors was undertaken. METHODS: Patients received IDR at a dose of 5 mg/m2/day x 3 days by intravenous bolus, followed by granulocyte-colony stimulating factor (G-CSF) at a dose of 5 microg/kg/day, starting on Day 7 of each cycle and continuing for at least 7 days, until the absolute neutrophil count was > or =10,000/mm3. RESULTS: Three of 19 patients with high grade astrocytoma achieved a partial response, 1 of 20 patients with medulloblastoma had a complete response, and 0 of 13 patients with ependymoma and 0 of 13 patients with brainstem tumors had responses. In nine other brain tumor patients there were no responses. The most significant toxicity was myelosuppression. CONCLUSIONS: IDR, given at a dose of 5 mg/m2/day x 3 days, is not sufficiently active against relapsed medulloblastoma, ependymoma, or brain stem tumors to warrant further study of this agent in a Phase III setting. The response rate for patients with relapsed high grade astrocytoma was 15% (95% confidence interval, 3.3-40%).

Pharmacokinetic and pharmacodynamic studies of fludarabine and cytosine arabinoside administered as loading boluses followed by continuous infusions after a phase I/II study in pediatric patients with relapsed leukemias. The Children's Cancer Group.

The sequential administration of fludarabine followed by cytosine arabinoside (ara-C) has demonstrated significant synergistic effects against the CEM human leukemic cell line. This in vitro synergism was investigated in a Phase I trial in pediatric patients with relapsed acute leukemia. The optimum concentrations of 9-beta-D-arabinofuranosyl 2-fluoroadenine and ara-C necessary to achieve significant drug synergism from in vitro studies were between 10 and 20 microM. Fludarabine was infused at a dose to attain a target plasma concentration of 10 microM for 48 h, followed by a continuous infusion of escalated ara-C doses to maintain plasma ara-C concentrations of 10, 12.5, 15, or 17.5 microM for 72 h. Thirteen patients with acute lymphocytic leukemia and 18 with acute myelocytic leukemia were entered into the study, 30 of whom were clinically evaluable for toxicity. Pharmacokinetic and pharmacodynamic studies were performed on specimens from 20 patients. The optimal 9-beta-D-arabinofuranosyl 2-fluoroadenine and ara-C concentrations in plasma were easily achieved after continuous infusion regimens of both drugs. Cellular ara-CTP is augmented 5-8-fold in leukemic cells from patients receiving fludarabine phosphate treatment followed by ara-C. The maximum tolerated plasma concentrations for this combination regimen was 10 microM fludarabine for 48 h followed by 72 h of 15 microM ara-C, which were achieved at dose level 3. A significant number of responses were also seen. Nine of 18 evaluable patients (50%) with acute myelocytic leukemia achieved complete or partial responses, and 3 of 9 evaluable patients with acute lymphocytic leukemia achieved complete or partial responses. Fludarabine and ara-C successfully eradicated bone marrow disease in 16 of 27 patients (59%), 23 patients of which had been treated previously with high-dose ara-C. These results verified the synergistic effect fludarabine exhibited in augmenting ara-CTP concentrations in patients' leukemic blasts, thus improving the clinical response in relapsed pediatric leukemias.

Feasibility, toxicity, and biologic response of interleukin-2 after consolidation chemotherapy for acute myelogenous leukemia: a report from the Children's Cancer Group.

PURPOSE: Although remission can be achieved in 80% of children with acute myelogenous leukemia (AML), many patients experience relapse. Because interleukin-2 (IL-2) can induce remission in patients with overt evidence of AML, we hypothesized that IL-2 given to patients in first remission after intensive consolidation chemotherapy might prevent relapse. This study sought to determine whether such an approach was feasible. PATIENTS AND METHODS: Twenty-one patients in complete remission received IL-2 after completion of treatment on Children's Cancer Group (CCG) protocol 2941. Recombinant IL-2 9 x 10(6) IU/m2 daily by continuous intravenous infusion (c.i.v.) was given for 4 days. After 4 days rest, IL-2 1.6 x 10(6) IU/m2 daily c.i.v. was resumed for 10 days. We monitored patients for toxicity and measured absolute lymphocyte count, the absolute count of cells that express CD56 and CD3 antigen, and soluble IL-2 receptor alpha-chain (sIL-2R alpha) levels before the start of IL-2 and after completion of each of the two courses of IL-2. RESULTS: Observed toxicities included fever (57%), vascular leak (48%), hypotension (38%), tachycardia (14%), rash (29%), septicemia (5%), thrombocytopenia (29%), elevated transaminase (14%), electrolyte disturbance (29%), and hyperglycemia (10%). No patient required cardiac pressors or transfer to an intensive care unit. All patients studied developed an increase in lymphocyte count, CD56 count, CD3 count, and sIL-2R alpha levels after treatment with IL-2. CONCLUSION: This schedule of IL-2 was reasonably well tolerated by children with AML in first remission. After treatment, increased levels of sIL-2R alpha were observed. CCG is conducting a randomized prospective trial to assess the efficacy of IL-2 to prevent the relapse of AML (CCG-2961).

Phase I/II study of idarubicin given with continuous infusion fludarabine followed by continuous infusion cytarabine in children with acute leukemia: a report from the Children's Cancer Group.

PURPOSE: The Children's Cancer Group (CCG) undertook a phase I study (CCG-0922) to determine a tolerable dose of idarubicin given with fludarabine and cytarabine in children with relapsed or refractory leukemia. The phase I study was extended to a limited phase II study to assess the activity of this combination in children with acute myelogenous leukemia (AML). PATIENTS AND METHODS: This was a multiinstitutional study within the CCG. Eleven patients were entered onto the phase I study: seven with AML, three with acute lymphoblastic leukemia (ALL), and one with chronic myelogenous leukemia (CML). The maximal-tolerated dose (MTD) of fludarabine and cytarabine determined in a previous study was a fludarabine loading dose (LD) of 10.5 mg/m2 followed by a continuous infusion (CI) of 30.5 mg/m2/24 hours for 48 hours, followed by cytarabine LD 390 mg/m2, then CI 101 mg/m2/h for 72 hours. Idarubicin was given at three dose levels: 6, 9, and 12 mg/m2 intravenously (I.V.) on days 0, 1, and 2. The phase II portion of the trial included 10 additional patients with relapsed or refractory AML. RESULTS: A dose of idarubicin 12 mg/m2/d for 3 days given in combination with fludarabine and cytarabine was tolerated. The major toxicity encountered was hematologic. Nonhematologic toxicities included transaminase elevations, hyperbilirubinemia, and infections. Eight of 10 patients with AML in the phase II portion (12 mg/m2 idarubicin) achieved a complete remission (CR). CONCLUSION: This combination is active in patients with relapsed or refractory AML. The major toxicity encountered is hematologic. This regimen may be useful therapy for AML and should be compared with standard induction therapy in children with newly diagnosed AML.

A phase II study of carboplatin as a treatment for children with acute leukemia recurring in bone marrow: a report of the Children's Cancer Group.

BACKGROUND: Carboplatin is an analogue of cisplatin with less nonhematologic toxicity and a similar spectrum of antineoplastic activity. Although cisplatin has not been found to be an active agent against leukemia, carboplatin-induced complete remissions have been observed in adults with acute myelogenous leukemia (AML), and antileukemic activity has been observed in a Phase I trial involving children with acute lymphoblastic leukemia (ALL) and AML. Therefore, a pediatric Phase II study was undertaken to determine the degree of activity of carboplatin in childhood ALL and AML. METHODS: Between October 1991 and November 1994, the Children's Cancer Group conducted a Phase II study of carboplatin given by 5-day continuous intravenous infusion to children with acute leukemia recurring in bone marrow. RESULTS: Minimal antileukemic activity was demonstrated in patients with ALL and AML. One of 21 eligible patients with ALL achieved a partial response. Of 23 eligible patients with AML, including 1 patient with chronic myelogenous leukemia in blast crisis, 1 had hypocellular M1 bone marrow with a platelet count of 15,000/mm3, and 2 achieved partial responses. Nonhematologic toxicities, which were infrequent, included mild hepatic and renal dysfunction. CONCLUSIONS: In this pediatric Phase II trial of carboplatin as a treatment for acute leukemia, minimal activity was demonstrated in patients with ALL and AML recurring in bone marrow. Further evaluation of carboplatin as a treatment for childhood leukemia, using the dose schedule of 216 mg/m2/day given by 5-day continuous intravenous infusion, does not appear warranted.