[Translational research and Cancer Plan]

The French Cancer Plan 2003-2007 has made translational research central to its research programme, to ensure the care-research continuum and the quickest application possible for the most recent discoveries, for the patients' benefit. This is a new field of research, still little-known or ill-understood. A working group, composed of physicians and researchers from academic research and industrial research, sought to define translational research in cancerology and define the issues at stake in it. Translational research needs to develop in close connection with the patients in order to enable a bi-directional flow of knowledge from cognitive research toward medical applications and from observations made on patients toward cognitive research. Placed under the aegis of the French National Cancer Institute and Leem Research, the group has put forth a strategy for implementing translational research in cancerology in France to make it attractive, competitive and efficient and to foster the development of public-private partnerships.

Dose finding study of oral PSC 833 combined with weekly intravenous etoposide in children with relapsed or refractory solid tumours

PSC 833 is an effective MDR1 reversal agent in vitro, including studies with paediatric cancer cell lines such as neuroblastoma and rhabdomyosarcoma. This study was performed to determine the safety profile, dose limiting toxicity (DLT) and maximum tolerated dose (MTD) in children with solid tumours and to determine the influence of PSC 833 on the pharmacokinetics of co-administered etoposide. Each patient received one cycle of intravenous etoposide (100 mg/m2 daily for 3 days on three consecutive weeks) to document baseline pharmacokinetics, and subsequently the same schedule using a dose of 50 mg/m2 was given combined with PSC 833 given orally every 6h at a starting dose of 4 mg/kg. Thirty two eligible patients (23 male, median age 8.3 years) were enrolled. Neuroblastoma and rhabdomyosarcoma were the common disease types. Brain tumours were excluded. DLT was defined as any non-haematological grade 3-4 toxicity (common toxicity criteria) and using a specific toxicity scale for cerebellar toxicity. The MDT was defined as the first dose below which 2 or more patients per dose level experienced DLT. Grade 1-2 ataxia occurred in cohorts 2 and 3 (4 and 5 mg/kg, respectively). Three patients developed grade 3 neurotoxicity in the 6 mg/kg cohort and this defined the MTD. Six responses were observed (2 CR, 4 PR). Pharmacokinetic studies indicated that the clearance of etoposide was reduced by approximately 50% when combined with PSC 833. It is concluded that the toxicity profile and MDT is similar in both children and adults, as is the effect on etoposide metabolism. The study demonstrated the feasibility and safety of carrying out a paediatric phase 1 trial across European boundaries and acts as a model for future cooperative studies in rare cancers among children.

Activation of the PI3K/Akt pathway in neuroblastoma

9523

Background: Neuroblastoma is a pediatric malignant neurorectodermal tumor with still a poor survival in children over 1 year of age. In cancer, the PI3K/Akt pathway contributes to tumor aggressiveness (proliferation, metastasis). It is a major target for novel anti- cancer therapies. The objective was to study the activation of the PI3K/Akt pathway in NB. Methods: 101 patients (median age 2.5 years, range: 0–13) with a resected neuroblastoma (16 stage I; 7, II; 22, III; 48, IV and 8, IVS) were included. Tissue microarrays were constructed containing 101 primary tumors, 39 paired metastases and 56 paired normal tissues. Immunohistochemical staining was performed on sections using antibodies against PI3K, Akt and phosphoAkt (S-473). The expression of membrane receptors (EGFR, HER-2, VEGFR1, VEGFR2, PDGFRa, PDGFRβ, IGF1Rβ, TrkB), proteins directly interfering with AKT (PTEN, mTOR) and downstream proteins (phospho-p70S6 kinase, 4eBP1) was studied. The intensity was evaluated by a semi-quantitative score based on the percentage of positive cells. The Wilcoxon signed rank test was applied for the comparison of paired data and adjusted for multiple testing using the False Discovery Rate criterion. Spearman correlation values (rho) were used to compare the expression between genes in the primary tumors. Results: 60% of the tumors expressed PI3K, 80% AKT and 73% pAKT. In addition, phospho-p70S6 kinase and 4eBP1p were expressed in 95% and 85%. All these proteins had a higher expression in tumors as compared with paired normal tissues (fdr-adjusted p<0.001). Akt and pAkt showed a tendency for higher expression in metastases as compared to paired primary tumors (raw p<0.05 for both, but fdr-p=0.11 and fdr-p=0.17 respectively). While EGFR, IGF1Rβ, TrkB, PDGFRa and PDGFRβ were significantly more expressed in primary tumors as compared to normal tissues (fdr-p<0.05), only IGF1Rβ seemed more expressed in metastases (fdr-p=0.09). A significant positive correlation was found between pAkt and the following: VEGFR1, VEGFR2 and IGF1Rβ (rho>0.34, p<0.001), phospho-p70S6 kinase and mTOR(rho>0.26, p<0.01). Conclusions: The PI3K/Akt pathway is activated in neuroblastoma and could be an attractive target for novel therapies. In addition, the data suggested that VEGFR and IGF1R are preferentially committed to this pathway activation.

No significant financial relationships to disclose.

ITCC phase I study of erlotinib as single agent in children with refractory and relapsed malignant brain tumors and in combination with irradiation in newly diagnosed brain stem glioma

9556

Background: Erlotinib hydrochloride (OSI-774), a selective inhibitor of the EGFR tyrosine kinase, may be active in childhood brain tumors, particularly in combination with irradiation. Methods: Multicenter, non-randomized phase I study with separate dose findings for erlotinib as single agent in children with refractory or relapsing brain tumors (group 1), and combined to irradiation in newly diagnosed brain stem glioma (group 2). Erlotinib was administered orally daily at 75, 100, 125 or 150 mg/m2. Dose escalation was performed in a classical 3+3 methodology for group 1 and according to the continuous reassessment method for group 2; dose-limiting toxicity (DLT) was evaluated at 3 and 6 weeks, respectively. Results: In total, 31 patients have been entered to date, 30 received treatment, 17 in group 1 (3 relapsing brain stem glioma, 4 ependymoma, 4 oligodendroglioma, 6 other) and 13 in group 2 with a median age of 9 and 6 years (range 4–16 and 2–12), respectively. Median treatment duration was 1.5 and >5 months, respectively. In group 1, 3 patients each were treated at 75 mg/m2 and 100 mg/m2, 7 at 125 mg/m2, 4 at 150 mg/m2. One patient with a glioneuronal tumor treated at 125 mg/m2 experienced G5 intra-tumoral hemorrhage at day 4 which was considered as DLT; at 150 mg/m2, 1 patient with an oligodendroglioma experienced G3 asthenia at day 18 and G3 intratumoral hemorrhage at day 29, and 1 patient with an ependymoma experienced G5 intra-tumoral hemorrhage at day 49. In group 2, 1/6 patients treated with erlotinib 75 mg/m2 and irradiation experienced seizures and died, no DLT occurred in 6 patients at 100 mg/m2. Non-hematological toxicities included G1-G2 erythema, folliculitis, dry skin, trichomegaly, G1 transaminitis, bilirubinemia, G1–3 asthenia, G1–5 intra-tumoral hemorrhage. Minor tumor response was observed in an oligodendroglioma. Pharmacokinetic and biological evaluations are ongoing. Conclusions: Erlotinib was well tolerated in children with cutaneous symptoms being the most frequent treatment toxicity. However, neurological toxicity and intra-tumoral hemorrhage was notable in these children with brain tumors. Inclusion at 125 mg/m2 is ongoing to confirm the MTD.

No significant financial relationships to disclose.

The topoisomerase I inhibitor gimatecan exhibits anti-tumor activity against malignant glioma xenografts as single agent and in combination

2081

Background: Gimatecan, a novel oral lipohilic camptotecan (ST1481; NVP-LBQ707), has shown to irinotecan and topotecan superior anti-tumor activity against several cell lines and human xenografts. We evaluated gimatecan in microemulsion in vivo alone and in combination with temozolomide and the EGFR and VEGF tyrosine kinase inhibitor AEE788 against subcutaneous malignant glioma xenografts derived from primary tumors. Results: Gimatecan exhibited dose-dependent activity against all three advanced tumor stage glioma models with IGRG93 being the most sensitive: 0.10 to 0.25 mg/kg gimatecan daily orally in a protracted schedule 5 days/week during 4 weeks resulted in 100% partial and complete tumor regressions, significant tumor growth delays (TGD; 48 to >100 days), log cell kills of 4.3 to 9.1, and were thus considered as ++++ highly active according to the SRI activity criteria. Anti-tumor activity in the TP53 wild-type IGRG93 correlated with significant induction of apoptotic cell death, as measured by TUNEL and cell cycle analysis, and lack of induction of p21. Moreover, combination of gimatecan and temozolomide resulted in synergistic activity against the TP53 wild-type IGRG121 glioblastoma and gimatecan at the MTD could be combined with temozolomide without enhanced toxicity. Gimatecan 0.19 mg/kg q5/wx4w combined with AEE788 50 mg/kg q3/wx4w was evaluated against the TP53 mutant, EGFR gene amplified IGRG88 glioma. Both agents were highly active resulting in 100% tumor regression. Gimatecan treated tumors started to grow 2–3 weeks after treatment end, while tumors treated with AEE788 regrew directly after treatment stop resulting in less significant TGD. Gimatecan and AEE788 given simultaneously during 4 weeks yielded less significant TGD compared to gimatecan alone, thus antagonistic effects. AEE788 induced G1 cell growth arrest which may reduce sensitivity to gimatecan, necessitating S-phase to be most efficient. An alternative schedule with gimatecan followed by AEE788 may be more appropriate. Conclusions: Gimatecan is highly active against malignant glioma xenografts and has synergistic activity with temozolomide suggesting this new topoisomerase I inhibitor for the treatment of malignant glioma.

No significant financial relationships to disclose.

Identification of novel candidate genes for ependymoma progression in chromosomal regions over-represented at recurrence and detected by CGH array

2008

Background: The biology and genetics of ependymomas remain poorly understood. As opposed to other pediatric tumors, few recurrent chromosomal abnormalities or relevant pathways have been identified. Method: In order to gain new insight into the molecular mechanisms involved in ependymoma progression, we performed BAC array-based comparative genomic hybridization (aCGH) in a series of 59 tumors at diagnosis and at relapse (42 posterior fossa and 17 supratentorial). Specific chromosomal imbalances were confirmed by FISH. Expression of candidate genes was evaluated by RT-PCR and immunohistochemistry. Results: As compared to CGH (Cancer Genet Cytogenet 2002), aCGH detected more abnormalities since 18/33 samples at diagnosis and 22/26 at recurrence showed chromosomal imbalances. Three distinct patterns were observed : no imbalance (15 at diagnosis, 4 at relapse), large and numerous imbalances (7 at diagnosis, 12 at relapse) and small and rare imbalances (11 at diagnosis, 10 at relapse). At diagnosis, absence of chromosomal imbalance was correlated with young age (p=0.034) and shorter progression-free survival (p=0.014). At relapse, patients with large and numerous imbalances had a shorter survival (p=0.026). Specific chromosomal imbalances were significantly more frequent at recurrence: 9 qter gain (54% vs 21%), 1q gain (12% vs 0%) and 6q loss (27% vs 6%). Samples were available both at diagnosis and relapse for 16 patients. Whole genome changes were towards increase of genomic abnormalities (n=10) but also simplification (n=6), the former being associated with a higher risk of death from disease (Fisher exact, p=0.03). A candidate gene strategy was focussed on the frequently gained 9qter locus. Significant overexpression compared to normal brain was identified for Tenascin-C (median 35 fold, max 220 fold, p<0.0001) and Notch1 (median 6 fold, max 45 fold, p<0.0001). Notch pathway analysis by RT-PCR revealed potential regulatory loops between JAG1/2 or DLL1/3 and Notch1/2. Conclusion: aCGH pattern may identify subgroups of ependymomas with respect to prognosis. Notch pathway and Tenascin-C are important regulatory genes in ependymoma progression and may represent interesting new targets for therapy.

No significant financial relationships to disclose.

Circulating endothelial cells and progenitor cells in metastatic renal cell cancer: Predictive value during anti-angiogenic therapy?

3555

Background: Anti-angiogenic therapy has demonstrated efficacy in the treatment of metastatic renal cell carcinoma (MRCC). New surrogate biomarkers are needed to optimize the potential of this novel therapy. Circulating endothelial cell (CEC) and progenitor cell (CEP) measurement has been proposed to monitor anti-angiogenic drug activity and treatment efficiency. Methods: 21 patients (pts) with MRCC were analysed. Among them, 16 were monitored both at baseline and 2 -3 weeks after start of anti-angiogenic treatment (14 pts received sutinimib and 2, nexavar). CECs were measured in one ml erythocyte lysed whole blood by four color flow cytometry (FCM) and identified by a CD45-CD31+CD146+ 7-amino-actinomycin (7AAD)- phenotype. Enumeration of CEC was validated by spiking whole blood with human umbilical vein cells and by immunohistochemical staining of the cell sorted fraction with endothelial markers (Ulex-Europaeus-lectin-1 and Von Willebrand factor). Median CEC value in 20 healthy subjects was 5.5 /ml (range 0–15) wheras this value was 16/ml (range 0–179) in 80 metastatic cancer patients. CEPs were measured by FCM as extremely rare events with a CD45dimCD34+ VEGFR2+7AAD- phenotype. Results: Median MRCC baseline CEC value was 17/ml (range 3 to 101). 16 pts had CEC levels that were two-fold greater than healthy subjects (>10/ml). Preliminary data showed a dramatic drop in CEC levels in patients that responded to therapy. Median baseline CEP value was 0.49% of hematopoietic stem cells (HSC), with ranges from 0.06% to 9% (absolute counts: 10/ml range 1 to 181/ml). Eight patients had CEP values greater than 1% of HSC and all had high tumor burden. Among the 16 pts monitored, all except 2 showed a dramatic increase in CEPs after treatment suggesting that anti-VEGFR2 targeted therapy might induce peripheral accumulation of CEP. Updated data and correlations with prognostic factors and clinical outcome will be presented. Conclusion: During anti-angiogenic therapy, dramatic changes in both CEC and CEP levels were observed. Predictive values of CEC and CEP are currently under evaluation.

No significant financial relationships to disclose.

Operating characteristics of two independent sample design in phase I trials in pediatric oncology

9555

Background: The European Medicine Agency (EMEA) stated that the degree of pre-treatments can modify the patient's tolerance to new treatments in pediatrics oncology, and then suggested that exploration of this potential difference should be considered. It is current practice to split a phase I trial in two groups to identify the Maximum Tolerated Dose (MTD) in each group. Yet how relevant such approach is, has not been investigated. In particular, role of baseline characteristics has not been explored. Methods: We reanalyze a large phase I trial of CPT11 in which 80 children had been included (32 heavily pre-treated pts and 48 less heavily pre-treated) to determine if baseline characteristics were associated with the heaviness of pre-treatment and could predict serious adverse events. To investigate robustness of conclusions in the context of small sample sizes, we performed an extended simulation study. We explored dose recommendations in scenarios with group difference, as measured by Odds Ratio (OR), ranging from 1 (absence of difference) to 8 (large difference) and sample size increasing from 2 * 20 to 2*40. Results: We did not find any relation between the degree and pre- treatment and neither the risk of DLT nor the baseline characteristics in this pediatric trial. However robustness appeared to be critical with high risk of misidentification of MTD in each of the two groups, whatever the prognostic value. With a group difference corresponding to OR=8 and balanced sample sizes (2*20 pts), the same MTD was identified in 10% of the simulations. Even with larger sample sizes (2*40pts), this figure reached 24% for OR=3. There is also a very high risk of identifying two different MTD although the risk is similar in the two groups (52% for 40 × 2 patients). Conclusions: Two independent sample designs in pediatric phase I trials should be avoided or reserved to limited situations when there is a strong rationale possibly based on adult data.

No significant financial relationships to disclose.

Prospective validation of a novel IV busulfan fixed dosing for paediatric patients to improve therapeutic AUC targeting without drug monitoring

INTRODUCTION

Oral busulfan clearance is age-dependent and children experience a wide variability in plasma exposure. BSA- or age-based dosing is used with therapeutic drug monitoring (TDM) to reduce this variability.

PURPOSE

A new intravenous (IV) dosing of busulfan (Bu) based on body weight, designed to improve AUC targeting without TDM and dose-adjustment, was prospectively evaluated.

METHOD

Bu was administered as a 2 h IV infusion every 6 h over 4 days (16 administrations). Five dose levels were defined on body weight as follows: 1.0 mg/kg for <9 kg; 1.2 mg/kg for 9 to <16 kg; 1.1 mg/kg for 16-23 kg; 0.95 mg/kg for >23-34 kg; 0.80 mg/kg for >34 kg. Bu treatment was followed by Cyclophosphamide or Melphalan prior to allogeneic or autologous transplantation in 55 children aged 0.3-17.2 years (median 5.6 years).

RESULTS

No difference in AUC values was observed between weight strata (mean +/- SD 1248 +/- 205 micromol.min), whereas a significant difference in Bu clearance was demonstrated. This new dosing enabled to achieve a mean exposure comparable to that in adults. At dose 1, 91% of patients achieved the targeted AUC range (900-1500 micromol.min) while no patients were underexposed. At doses 9 and 13, over 75% of patients remained within that target whilst most of the others were slightly above. Successful engraftment was achieved in all patients. In conclusion, from infants to adults this new dosing enabled, without TDM and dose adjustment, to successfully target a therapeutic AUC window.

Elevated plasma ferritin and busulfan pharmacodynamics during high-dose chemotherapy regimens in children with malignant solid tumors

Hepatic veno-occlusive disease (HVOD) is a frequent complication during hematopoietic stem-cell transplantation (HSCT). A strong relationship has been demonstrated between busulfan exposure and HVOD for busulfan-cyclophosphamide and allogeneic HSCT in adults. Busulfan disposition after the first intake was studied in 77 children treated for solid malignancies with high-dose busulfan-containing regimens and autologous HSCT. Busulfan was combined with cyclophosphamide and melphalan (n=30), melphalan (n=27), and thiotepa (n=20). No relationship was observed between busulfan exposure and HVOD. In contrast, plasma ferritin at baseline was higher in patients with HVOD (750 ng/ml (20-3,110)) compared with those without HVOD (189 ng/ml (8-3,967), P=0.012). Multivariate analysis showed that a ferritin level exceeding 300 ng/ml was the only risk factor for HVOD with an odds ratio of 4.0 (confidence interval 95% (1.5-11.2), P=0.0071). A high ferritin level at baseline was explained by the diagnosis of neuroblastoma, related treatments and transfusions.

A phase I study of intravenous liposomal daunorubicin (DaunoXome) in paediatric patients with relapsed or resistant solid tumours

Anthracyclines are widely used in paediatric oncology, but their use is limited by the risk of cumulative cardiac toxicity. Encapsulating anthracyclines in liposomes may reduce cardiac toxicity and possibly increase drug availability to tumours. A phase I study in paediatric patients was designed to establish the dose limiting toxicity (DLT) and maximum tolerated dose (MTD) after a single course of liposomal daunorubicin, ‘DaunoXome’, as a 1 h infusion on day 1 of a 21 day cycle. Patients were stratified into two groups according to prior treatment: Group A (conventional) and group B (heavily pretreated patients). Dose limiting toxicity was expected to be haematological, and a two-step escalation was planned, with and without G-CSF support. Pharmacokinetic studies were carried out in parallel. In all, 48 patients aged from 1 to 18 years were treated. Dose limiting toxicity was neutropenia for both groups. Maximum tolerated dose was defined as 155 mg m⁻² for Group A and 100 mg m⁻² for Group B. The second phase with G-CSF was interrupted because of evidence of cumulative cardiac toxicity. Cardiac toxicity was reported in a total of 15 patients in this study. DaunoXome shares the early cardiotoxicity of conventional anthracyclines in paediatric oncology. This study has successfully defined a haematological MTD for DaunoXome, but the significance of this is limited given the concerns of delayed cardiac toxicity. The importance of longer-term follow-up in patients enrolled into phase I studies has been underestimated previously, and may lead to an under-recognition of important adverse events.

Pleiotrophin, a candidate gene for poor tumor vasculature and in vivo neuroblastoma sensitivity to irinotecan

In vivo neuroblastoma (NB) xenograft model, resistant to the DNA-topoisomerase I inhibitor irinotecan (CPT-11), has been established to study resistance mechanisms acquired in a therapeutic setting. Common mechanisms of resistance were not involved in this resistance. Thus, we compared the gene expression profiles of sensitive, resistant, and reverted tumors using cDNA expression arrays. Expression of selected transcripts was confirmed by quantitative real-time PCR. We found that pleiotrophin (PTN), a heparin-binding growth factor, was the only gene significantly affected: PTN gene expression was downregulated in all resistant tumors (8-14-fold) as compared to sensitive tumors, and was increased (2-4-fold) in all reverted tumors as compared to resistant tumors. PTN thus appeared to be a likely candidate gene associated with resistance to CPT-11 in this in vivo model. To investigate the direct implication of PTN in NB, we transfected two NB cell lines with RNA interferences in order to silence PTN. PTN failed to demonstrate implication in resistance to CPT-11 in vitro but could influence sensitivity to CPT-11 exclusively through an in vivo mechanism. Indeed, vasculature was significantly enhanced in resistant NB xenografts compared to sensitive and reverted xenografts, and we suggest that PTN is acting in our resistant in vivo NB model as an angiostatic factor.

Preliminary data of a phase I-II clinical and pharmacokinetic study of plitidepsin in children with malignant tumors. On behalf of the European ITCC (Innovative Therapies for Children with Cancer) Consortium

9060

Background: Plitidepsin (Aplidin) is a cyclic depsipeptide isolated from the tunicate Aplidium albicans, nowadays manufactured by synthesis. It is a rapid and potent inductor of apoptosis. Phase I trials in adults explored 5 different schedules. Muscle and liver toxicities were dose-limiting; hematological toxicity was not observed at the recommended dose (RD). Methods: This is a multicentre, open-label, non-randomized phase I-II study with a dose finding stage in children with solid tumors, and two expanded cohorts in leukemia and solid tumors at the RD. Plitidepsin was administered as a 3 h iv infusion every 2 weeks (=1 cycle). The initial dose level was 4 mg/m2 (80% of the RD in adults), with a classical escalation to 5 and 6 mg/m2. Results: 16 patients have been entered to date with median age 7.5 years (range 2–17). 54 cycles in 15 patients were evaluable for toxicity. 8 patients were treated at 4 mg/m2, five at 5 mg/m2 and three at 6 mg/m2. One patient presented dose-limiting G2 myalgia lasting more than 2 weeks at 4mg/m2. The Maximum Tolerated Dose (MTD) has not been reached at 6 mg/m2. Non-hematological toxicities included G1-G2 muscle side effects: (myalgia, CPK elevation, muscle weakness), G1–2 fatigue, G3 vomiting. One G3 hypersensitivity reaction was observed without prophylactic treatment. Pharmacokinetic data are similar to those reported in adult (extensive tissue distribution, a long half-life); if any, clearance was slightly higher and half-life shorter. Partial response was observed in a pancreatoblastoma and disease stabilization in a progressive medulloblastoma. Conclusions: Plitidepsin was well tolerated in children, with muscular side effects being the most relevant toxicity observed. The MTD for the pediatric population has not yet been achieved at a dose 1.2 fold above the RD in adults.

[Table: see text]

ITCC phase II study of imatinib mesylate in children with solid tumors expressing imatinib-sensitive tyrosine kinase receptors

9003

Background: Imatinib mesylate inhibits selectively specific activations of the platelet-derived growth factor receptor (PDGFR), c-KIT and BCR/ABL tyrosine kinases and is approved for the treatment of chronic myeloid leukemia and gastro-intestinal stromal tumors (GIST). This study evaluated efficacy of imatinib in solid childhood tumors. Methods: Phase II study of imatinib as single agent in children and adolescents with refractory or relapsing solid tumor expressing at least one of the receptors. Patients were to be treated at 340 mg/m2, a dose escalation allowed to 440 mg/m2 after 2 months in case of insignificant improvement. C-KIT, PDGFRα and β expression was determined on archive tissue sections by immunohistochemistry prior to study entry. Gene mutations, pharmacokinetics, pharmacogenetics, and positron emission tomography imaging were assessed. Results: 36 patients, 21 boys, median age 13.7 years (2.2–22.5 y), 12 with brain tumors, 6 fibromatosis, 8 mesenchymal/bone tumors, and 10 other solid tumors, including 1 GIST and 3 chordoma, were treated at 340 mg/m2 daily during a total of 168 months (median 1.9 month/patient, range 0.5–19). 18/36 expressed c-KIT, 10 PDGFRα, 21 PDGRβ; 12 expressed more than one receptor. Ten patients were escalated to 440 mg/m2 due to lack of efficacy. During the 1st month, 17 patients experienced mild toxicity (grade 1 and 2) related to study treatment: gastro-intestinal (n=22), face edema (n=7), asthenia (n=5), tumor induration (n=2), skin toxicity (n=2), thrombocytopenia (n=1). No partial or complete response was observed; 5 patients (2 fibromatosis, 1 GIST, 1 medulloblastoma, 1 pseudo-inflammatory tumor) experiencing durable stable disease have been under treatment for more than 12 months. Interesting tumor stabilization during 10 and 7 months, respectively, was achieved in a brain stem glioma and a renal carcinoma. Glucose uptake on 18FDG PET scan was reduced in a chordoma, although the child progressed and died due to disease. Pharmacokinetic and genetic data are currently evaluated. Conclusions: Imatinib as single agent was well tolerated, but—as used in our study —failed to show measurable anti-tumor effects according the standard criteria in the pediatric malignancies studied.

No significant financial relationships to disclose.

Expression of erythropoietin and its receptor in neuroblastomas

9054

Background: Children with neuroblastomas (NB) may potentially benefit from treatment with recombinant human erythropoietin (Epo). Epo is a specific stimulator of erythropoiesis, acting via its specific receptor (EpoR). The aim of this study was to evaluate the expression of Epo and EpoR in NB and in normal tissues and their action in the proliferation of tumor cells. Methods: A tissue microarrays study was performed on 101 patients with NB from 3 hospitals (16 stage I; 7, II; 22, III; 48, IV and 8, IVS). Four blocks were constructed and contained 101 primary tumors, 39 paired metastases (35 lymph nodes), 56 paired control normal tissues and 6 cell lines of NB. Immunohistochemical staining was performed on sections using antibodies against Epo and EpoR. Immunostaining intensity was evaluated by a semi-quantitative score based on the percentage of positive cells. The wilcoxon signed rank test was applied for the comparison of paired data. For overall survival analysis, the expression was dichotomized at the median value and cox regression models were used stratified by hospital. An in vitro study of cell proliferation in presence of recombinant Epo was carried out with two of the 6 cell lines, one expressing EpoR, the other not. Results: Median follow-up was 64 months. The expression of EpoR was significantly higher in tumors than in paired control tissues (p<0.0001) but not for Epo (p=0.06). When restricted to the lymph nodes metastases, the level of expression of EpoR was significantly more expressed in the metastases than in primary tumors (p=0.02), contrary to Epo (p=0.99). Survival analysis showed that patients who expressed more EpoR had a statistically significant better overall survival than those who did not (p=0.03). Furthermore, the expression of EpoR was an independent prognostic factor from induction chemotherapy, tumor stage and age (p=0.02). No significant differences were found in Epo analyses. EpoR was expressed in only three cell lines and Epo not in any of them. In the in vitro study, recombinant Epo did not modify the proliferation of both cell lines. Conclusions: Epo and EpoR were expressed in NB but did not modify cells proliferation. The use of Epo in children with NB could be proposed but its benefit should be confirmed in a clinical trials.

No significant financial relationships to disclose.

Temozolomide phase II study in children with relapsing refractory high-risk neuroblastoma

9012

Background: To determine the response rate (RR) of neuroblastoma (NB) in children to temozolomide (TMZ), and evaluate the duration of response and tolerance of the drug in this patient population. Methods: A multicenter, phase II evaluation of an oral, daily schedule of TMZ (200 mg/m2 on 5 consecutive days and repeated every 28 days) was undertaken in children with a refractory or relapsed high-risk NB (metastatic or localized with Myc-N amplification). Evidence of activity was defined by radiologic or MIBG scan evidence of sustained reduction in lesion size or activity whenever it occurs. Methodology included a two-step study using Fleming’s method with a first step of 15 patients and a second of 10 additional patients if 2 to 4 responses had been observed in the first cohort. All data were centrally reviewed by a panel. Results: Among 34 registered patients over a 14 month period in 14 centres, twenty five are finally evaluable and received 94 cycles of chemotherapy. Disease status was metastatic NB (n=23) either refractory (n=9) or in relapse (n=14). Grade ¾ thrombocytopenia was the most frequent toxic event (16% of the cycles). Myelosuppression resulted in significant treatment delays and dose reductions (24% and 21% of cycles respectively). Out of 25 patients, response (CR, VGPR or PR) was observed in 5 (RR=20 ± 8%) with a median duration of 6 months. Furthermore a mixed response or an objective effect was observed in respectively 2 and 3 additional patients. Conclusions: Temozolomide is effective in heavily pretreated patients with NB, and deserves further evaluation in combination with another drug

No significant financial relationships to disclose.

[Targeted therapies in pediatric oncology: a new therapeutic approach?]

A multidisciplinary therapeutic approach has led to significant increase in survival of children with cancer, however often with a high rate of severe sequela. Better understanding in tumor cell biology and transformation process allowed to describe active tyrosine kinases (mainly growth factor receptors) as a new target for cancer treatment. This review presents 2 approaches to target receptor tyrosine kinase activity: on one hand, antibodies that target the extracellular domain, the natural ligand binding site, and on the other hand, small inhibiting molecules, such as imatinib, targeted against the activated intracellular receptor tyrosine kinase. We focus on their clinical development and current application in the treatment of childhood cancer. Targeted therapies are in full rise and new perspectives are explored, such as their association to other treatment modalities and the targeting of microenvironment. This new therapeutic approach necessitates well designed clinical trials that include relevant biomarkers to evaluate its real therapeutic potential.

Dose finding and O6-alkylguanine-DNA alkyltransferase study of cisplatin combined with temozolomide in paediatric solid malignancies

Cisplatin may have additive activity with temozolomide due to ablation of the DNA repair protein O⁶-alkylguanine-DNA alkyltransferase (MGMT). This phase I/II study determined recommended combination doses using the Continual Reassessment Method, toxicities and antitumour activity in paediatric patients, and evaluated MGMT in peripheral blood mononuclear cells (PBMCs) in order to correlate with haematological toxicity. In total, 39 patients with refractory or recurrent solid tumours (median age ∼13 years; 14 pretreated with high-dose chemotherapy, craniospinal irradiation, or having bone marrow involvement) were treated with cisplatin, followed the next day by oral temozolomide for 5 days every 4 weeks at dose levels 80 mg m⁻²/150 mg m⁻² day⁻¹, 80/200, and 100/200, respectively. A total of 38 patients receiving 113 cycles (median 2, range 1–7) were evaluable for toxicity. Dose-limiting toxicity was haematological in all but one case. Treatment-related toxicities were thrombocytopenia, neutropenia, nausea-vomiting, asthenia. Hearing loss was experienced in five patients with prior irradiation to the brain stem or posterior fossa. Partial responses were observed in two malignant glioma, one brain stem glioma, and two neuroblastoma. Median MGMT activity in PBMCs decreased after 5 days of temozolomide treatment: low MGMT activity correlated with increased severity of thrombocytopenia. Cisplatin–temozolomide combinations are well tolerated without additional toxicity to single-agent treatments; the recommended phase II dosage is 80 mg m⁻² cisplatin and 150 mg m⁻² × 5 temozolomide in heavily treated, and 200 mg m⁻² × 5 temozolomide in less-heavily pretreated children.

No topoisomerase I alteration in a neuroblastoma model with in vivo acquired resistance to irinotecan

CPT-11 (irinotecan) is a DNA-topoisomerase I inhibitor with preclinical activity against neuroblastoma (NB) xenografts. The aim was to establish in vivo an NB xenograft resistant to CPT-11 in order to study the resistance mechanisms acquired in a therapeutic setting. IGR-NB8 is an immature NB xenograft with MYCN amplification and 1p deletion, which is sensitive to CPT-11. Athymic mice bearing advanced-stage subcutaneous tumours were treated with CPT-11 (27 mg kg⁻¹ day⁻¹ × 5) every 21 days (1 cycle) for a maximum of four cycles. After tumour regrowth, a new in vivo passage was performed and the CPT-11 treatment was repeated. After the third passage, a resistant xenograft was obtained (IGRNB8-R). The tumour growth delay (TGD) was reduced from 115 at passage 1 to 40 at passage 4 and no complete or partial regression was observed. After further exposure to the drug, up to 28 passages, the resistant xenograft was definitively established with a TGD from 17 at passage 28. Resistant tumours reverted to sensitive tumours after 15 passages without treatment. IGR-NB8-R remained sensitive to cyclophosphamide and cisplatin and cross-resistance was observed with the topoisomerase I inhibitor topotecan. No quantitative or qualitative topoisomerase I modifications were observed. The level of expression of multidrug resistance 1 (MDR1), MDR-associated protein 1 (MRP1) and, breast cancer resistance protein, three members of the ATP-binding cassette transporter family was not modified over passages. Our results suggest a novel resistance mechanism, probably not involving the mechanisms usually observed in vitro.

Temozolomide in paediatric high-grade glioma: a key for combination therapy?

This report describes a single-centre study with temozolomide (TMZ) (200 mg m⁻² day⁻¹ × 5 per cycle of 28 days) in children with (recurrent) high-grade glioma. Magnetic resonance imaging was performed every two cycles. In all, 20 patients were treated between 1998 and 2001 after the UKCCSG/SFOP TMZ phase II trial. All patients had measurable disease. Totally, 15 patients had a relapse after surgery±radiotherapy±chemotherapy. Overall, five patients received TMZ after surgery or biopsy, awaiting radiotherapy. There were one clinically malignant grade II glioma, 11 grade III and eight grade IV gliomas. Seven tumours had oligodendroglial features. Mean age at start of TMZ was 12.0 years (range 3–20.5 years). In total, eight patients had >8 cycles (range 3–30). One VGPR (currently in CR after surgery), three PRs (with a PFS of 4, 4 and 11 months, respectively) and one MR (PFS 14 months) were observed. Three out of five responses occurred after >4 courses. The overall response rate was 20%. Median progression-free survival (PFS) was 2.0 months (range 3 weeks–34⁺ months). PFS rate was 20% after 6 months. Median overall survival (OS) was 10 months. Nine patients showed a clinical improvement. Three patients vomitted shortly after TMZ administration, eight patients (13 cycles) experienced grade III/IV thrombocytopenia, occurring predominantly during the fourth week of the first two cycles. Five patients experienced neutropenia, and three patients febrile neutropenia. TMZ is a well-tolerated ambulatory treatment for children with malignant glial tumours. This drug warrants further study in these highly chemoresistant tumours and should be studied either as upfront therapy or in combination therapy.

European collaboration in trials of new agents for children with cancer

Childhood cancer is a relatively rare disease, representing just 1% of all malignancies. Within Europe, this represents some 12,000 new cases each year, with approximately 1600 a year in the United Kingdom and 1800 in France. International collaboration in phase III trials of childhood cancer has been the norm for many years, traditionally within Europe, but, largely because of organisational considerations, phase I and II trials have only been conducted on a national basis. With overall cure rates in the region of 70%, relatively few children are available for these early drug trials. Access to new drugs is also a major problem. Against this background, a United Kingdom (UK)/French 'new agent' collaboration was established, expanding subsequently into a wider European grouping. This paper documents the history of that collaboration, the outcomes and future challenges.

Outcome of flat bone sarcomas (other than Ewing's) in children and adolescents: a study of 25 cases

We analysed the clinical features and outcome of young patients with non-Ewing's flat bone sarcoma treated during the era of contemporary chemotherapy. The characteristics and outcome of 25 patients (15 males and 10 females) with primary or radiation-related flat bone sarcoma treated in the Pediatrics Department at the Institut Gustave Roussy from 1981 to 1999 were reviewed. In all, 20 patients had osteosarcoma, four chondrosarcoma and one malignant fibrous histiocytoma. The age at diagnosis ranged from 2 to 23 years (median, 15 years). Nine tumours were located in the craniofacial bones, 11 in the pelvis and five in flat bones at other sites. Four patients had metastatic disease at diagnosis. Radiation-associated flat bone osteosarcoma was diagnosed in 10 out of 25 cases. The projected overall survival and event-free survival (EFS) rates at 5 years were 45.1 and 34.3% for all the 25 patients. The EFS rate of patients with second bone sarcoma was similar to that of patients with de novo flat bone sarcoma (P=0.1). The aim of treatment was curative for 24 patients, 23 of whom were treated with intensive chemotherapy regimens and 19 with surgery. Significant adverse prognostic factors on survival included incomplete surgical resection (P=0.001) and use of regimens without pre- and postoperative chemotherapy (P=0.007). Nine of the 25 patients were treated with pre- and postoperative chemotherapy and complete surgical resection. Among them, eight are alive with no disease. Radical surgical resection is the overriding prognostic factor for flat bone sarcomas in young patients. Nevertheless, our results suggest a more favourable outcome since the advent of intensive chemotherapy.

In children and adolescents, the pharmacodynamics of high-dose busulfan is dependent on the second alkylating agent used in the combined regimen (melphalan or thiotepa)

A strong relationship has been demonstrated between high systemic exposure to busulfan and the occurrence of hepatic veno-occlusive disease (HVOD) after a busulfan-cyclophosphamide regimen (BU CY). We report a prospective study aimed at exploring the pharmacodynamics of high-dose busulfan combined with either melphalan (BU MEL) or thiotepa (BU TTP) followed by autologous stem cell transplantation in children and adolescents with a malignant solid tumor. Busulfan was given orally at a total dose of 600 mg m(-2). In all, 45 patients with a median age of 6.3 years were included in the study: 25 received BU MEL and 20 received BU TTP. The incidence of HVOD was 44% (CI 95% [23-65%]) in the BU MEL group and 25% (CI95% [9-49%]) in the BU TTP group. In the BU TTP group, patients who developed HVOD had a significantly higher AUC 0-6 h after the 13th dose (6201+/-607 h ng ml(-1)) than those who did not (5024+/-978 h ng ml(-1)) (P<0.05). In the BU MEL group, there was no difference in terms of systemic exposure to busulfan between patients who developed HVOD and those who did not. In conclusion, the guidelines established for monitoring BU CY cannot be extrapolated when busulfan is combined with another drug.

Potentiation of tumour apoptosis by human growth hormone via glutathione production and decreased NF-kappaB activity

In addition to its primary role as growth factor, human growth hormone (hGH) can also participate in cell survival, as already documented by its protective effect on human monocytes or human promyelocytic leukaemia U937 cells exposed to a Fas-mediated cell death signal. However, despite similarities in the molecular events following Fas and TNF-alpha receptor engagement, we report that U937 cells, genetically engineered to constitutively produce hGH, were made more sensitive to TNF-alpha-induced apoptosis than parental cells. This was due to overproduction of the antioxidant glutathione, which decreased the nuclear factor (NF)-kappaB activity known to control the expression of survival genes. These findings were confirmed in vivo, in nude mice bearing U937 tumours coinjected with recombinant hGH and the NF-kappaB -inducing anticancer drug daunorubicin, to avoid the in vivo toxicity of TNF-alpha. This study therefore highlights one of the various properties of hGH that may have potential clinical implications.

Potentiation of radiation therapy by the oncolytic adenovirus dl1520 (ONYX-015) in human malignant glioma xenografts

In spite of aggressive surgery, irradiation and/or chemotherapy, treatment of malignant gliomas remains a major challenge in adults and children due to high treatment failure. We have demonstrated significant cell lysis and antitumour activity of the E1B-55 kDa-gene-deleted adenovirus ONYX-015 (dl1520, CI-1042; ONYX Pharmaceuticals) in subcutaneous human malignant glioma xenografts deriving from primary tumours. Here, we show the combined efficacy of this oncolytic therapy with radiation therapy. Total body irradiation (5 Gy) of athymic nude mice prior to intratumoral injections of ONYX-015 1 x 10(8) PFU daily for 5 consecutive days yielded additive tumour growth delays in the p53 mutant xenograft IGRG88. Radiation therapy was potentiated in the p53 functional tumour IGRG121 with a 'subtherapeutic' dose of 1 x 10(7) PFU daily for 5 consecutive days, inducing significant tumour growth delay, 90% tumour regression and 50% tumour-free survivors 4 months after treatment. These potentiating effects were not due to increased adenoviral infectivity or replication. Furthermore, cell lysis and induction of apoptosis, the major mechanisms for adenoviral antitumour activity, did not play a major role in the combined treatment strategy. Interestingly, the oncolytic adenovirus seemed to accelerate radiation-induced tumour fibrosis. Potentiating antitumour activity suggests the development of this combined treatment for these highly malignant tumours.

Individual dosing of carboplatin based on drug monitoring in children receiving high-dose chemotherapy

Individual dosing of carboplatin based on drug monitoring was performed within a multi-centric phase I study based on high AUC-levels in children. Twelve patients (aged 3-17 years old) have been included: 3, 5, and 4 patients at the overall target ultrafilterable carboplatin AUC of 20, 25, or 30 mg/ml x min, respectively. Carboplatin was administered as a daily 60-min infusion, repeated on five consecutive days. The initial daily dose corresponding to the three first days was calculated according to the carboplatin clearance (CL) predicted from patients' characteristics (body weight, serum creatinine and nephrectomy status). Three blood samples were taken per patient. The individual CL were estimated by MAP (maximum a posteriori approach) Bayesian method implemented in the MP-K program. The doses for day 4 and 5 was adjusted in order to obtain the overall target AUC. Drug monitoring led to a change in the carboplatin dose (overall administered dose versus overall dose planned) ranging from -41% to +45%. Pharmacokinetics were performed at day 5 for 7/12 children: mean relative change between day 1 and day 5 was -11% showing a statistically significant, but limited, decrease of CL from day 1 to day 5. The percentage of difference between the observed and target overall AUC ranged between -7% and +14%. Three patients (one at each AUC level) who were previously treated with cisplatin experienced dose-limiting hearing loss. In conclusion, drug monitoring and dose adjustment is needed for the control of carboplatin plasma exposure when administering high doses of carboplatin in children.

Multicentre phase II study and pharmacokinetic analysis of irinotecan in chemotherapy-naïve patients with glioblastoma

BACKGROUND

To assess the antitumour activity and safety profile of irinotecan and its pharmacokinetic interactions with anticonvulsants in patients with glioblastoma multiforme.

PATIENTS AND METHODS

This multicentre phase II and pharmacokinetic study investigated the effects of irinotecan 350 mg/m(2) given as a 90-min infusion every 3 weeks either prior to (group A) or after relapse following radiotherapy (group B) in chemotherapy-naïve patients with glioblastoma. Preferred concomitant medication for seizure prevention was valproic acid. Pharmacokinetic analysis of irinotecan and its main metabolites (SN-38, SN-38-G, APC and NPC) was performed during cycle 1. An independent panel of experts reviewed the activity data.

RESULTS

Fifty-two patients (25 patients in group A and 27 patients in group B) received a total of 191 cycles of irinotecan. Forty-six patients (22 patients in group A and 24 patients in group B) were evaluable and externally reviewed for activity. According to external review, one partial response (group B), seven minor responses (three in group A and four in group B), 12 disease stabilisations (seven in group A and five in group B) were observed. This resulted in an overall response rate of only 2.2% (95% confidence interval 0.2% to 6.5%). The median time to tumour progression was 9 weeks in group A and 14.4 weeks in group B. Six-month progression-free survival rates were 26% in group A and 43% in group B. Grade 3-4 toxicities (percentage of patients in groups A and B) consisted of neutropenia (12.5% and 25.9%), diarrhoea (8.3% and 7.4%), asthenia (12.5% and 7.4%) and vomiting (0% and 7.4%). The clearance of irinotecan was 12.4 and 14.4 l/h/m(2) in two patients who received no anticonvulsant. In patients receiving valproic acid, the clearance of irinotecan was 17.2 +/- 4.4 l/h/m(2).

CONCLUSIONS

Irinotecan given at the dose of 350 mg/m(2) every 3 weeks has limited clinical activity as a single agent in patients with newly diagnosed and recurrent glioblastoma after radiotherapy. The toxicity profile and plasma disposition of irinotecan and SN-38 were not strongly influenced by anticonvulsant valproic acid therapy. Although the response rate of irinotecan as a single agent was limited, it remains an attractive drug for combination studies in patients with glioblastoma.

Temozolomide in malignant gliomas of childhood: a United Kingdom Children's Cancer Study Group and French Society for Pediatric Oncology Intergroup Study

PURPOSE

To determine the response rate of the malignant gliomas of childhood to an oral, daily schedule of temozolomide.

PATIENTS AND METHODS

A multicenter, phase II evaluation of an oral, daily schedule of temozolomide (200 mg/m(2) on 5 consecutive days) was undertaken in children with relapsed or progressive, biopsy-proven, high-grade glioma (arm A) and progressive, diffuse, intrinsic brainstem glioma (arm B). Evidence of activity was defined by radiologic evidence of a sustained reduction in tumor size on serial magnetic resonance imaging scans.

RESULTS

Fifty-five patients were recruited (34 to arm A and 21 to arm B) and received 215 cycles of chemotherapy. Grade 3/4 thrombocytopenia was the most frequent toxic event (7% of cycles). Prolonged myelosuppression resulted in significant treatment delays and dose reductions (17% and 22% of cycles, respectively). Two toxic deaths were documented and were related to myelosuppression and sepsis in one patient and pneumonia in a second. The overall (best) response rate was 12% for arm A (95% confidence interval [CI], 3 to 28 in the study cohort, and 2 to 31 for eligible patients) and 5% and 6%, respectively, for arm B (95% CI, 0 to 26 in the study cohort, and 0 to 27 for eligible patients). Stabilization of disease was also documented and was most noteworthy for brainstem gliomas, where two patients achieved both radiologic static disease and discontinued steroid medication.

CONCLUSION

Despite moderate toxicity, objective response rates to temozolomide have been low, indicating that temozolomide has minimal activity in the high-grade gliomas of childhood.

Use of a topoisomerase I inhibitor (irinotecan, CPT-11) in metastatic adrenocortical carcinoma

BACKGROUND

Complete responses are rare after medical treatment of adrenocortical tumors. We performed a single center prospective study of the antitumor effect of irinotecan (CPT-11) in patients with metastatic adrenocortical cancer.

PATIENTS AND METHODS

Since 1999, all patients with advanced progressive adrenocortical carcinoma, referred to the Institut Gustave-Roussy, have been enrolled prospectively in this study. CPT-11 (250 mg/m(2)) was administered intravenously on day 1 in a 2-h infusion, every 14 days. World Health Organization (WHO) criteria were used to evaluate tumor response and toxicity.

RESULTS

During treatment, no dose or schedule modifications were made. A median of three courses were given (range 1-8), and all but two patients received at least three complete chemotherapy courses. No objective or complete responses were observed. The best response achieved was stabilization in three patients, lasting from 1.5 to 4 months. Significant toxicity occurred in two patients.

CONCLUSIONS

Our results do not support a major role of CPT-11 in adrenocortical carcinoma.

[Statutory pediatric informations available for anticancer drugs: inventory and proposals]

Paediatric medicines are often prescribed off label because appropriate clinical and pharmacological studies have not been conducted in children. A European directive is being written to promote the development of paediatric medicines through incentives to pharmaceutical companies, as is already the case in the US.

METHOD

In order to evaluate the status of anticancer drugs, we analyzed the paediatric information available in the Vidal 2000 dictionary for cytotoxic chemotherapy.

RESULTS

Among the 76 products, 48 were currently used to treat children with cancer. An indication for paediatric use was described in only 29% of them. Paediatric use was mentioned in the posology chapter in 56% of cases, and in the warning or contra-indication chapter in 17% of cases. Ten products (21%) were devoid of paediatric information.

DISCUSSION

The paucity of this official paediatric information contrasts with the number of clinical and pharmacological studies that have been conducted and published by paediatric oncology societies and groups. Indeed, almost 80% of children with cancer are treated using prospective therapeutic research protocols. In conclusion, anticancer medicines have been evaluated in children, but official paediatric information is poor. This situation can be significantly improved with the literature currently available. On the other hand, prospective clinical studies are needed to better define the optimal dose in children under one year of age, to evaluate long-term sequelae in cured patients and to provide appropriate galenic forms for oral chemotherapy.

CONCLUSION

Incentives are urgently needed to facilitate access to therapeutic innovations in oncology and their development in children with cancer.

Human growth hormone gene transfer into tumor cells may improve cancer chemotherapy

Chemotherapy remains the main tool for the treatment of cancers, but is often hampered by tumor cell resistance. In this context, the transfer of genes able to accentuate the effect of anticancer drugs may constitute a useful approach, as exemplified by inactivation of nuclear factor (NF)-kappa B via direct transfer of a gene encoding a negative dominant of its natural inhibitor I kappa B, leading to improved response to cancer chemotherapy. Following our previous report that transfection of human growth hormone (hGH) gene into human monocytic cell lines may also inactivate NF-kappa B in another situation, we decided to test the consequences of hGH gene transfer on cancer treatments. We demonstrated that hGH-transfected human myeloid leukemia U937 cells were sensitized to an apoptotic signal mediated by the anticancer drugs. In parallel, we found that, by inhibiting degradation of I kappa B, hGH gene transfer diminished NF-kappa B entry into the nuclei of U937 cells exposed to daunorubicin. Finally, we report that hGH-transfected tumor cells engrafted in nude mice responded in vivo to chemotherapy with nontoxic doses of daunorubicin whereas, under the same conditions, control tumor cells remained insensitive. Overall, this study therefore suggests that hGH gene transfer may offer new therapeutic prospects in cancer therapy.

[Methotrexate-ciprofloxacin interaction: report of two cases of severe intoxication]

Methotrexate elimination may be delayed by different drugs. Such a delay may produce severe toxic complications.

CASE REPORTS

We report two cases of adolescents treated for malignant diseases who presented a delayed methotrexate elimination even though they received ciprofloxacin. The first patient had already received several courses of methotrexate without toxicity before this episode. The second patient tolerated methotrexate when ciprofloxacin was not associated to the treatment.

CONCLUSION

High-dose methotrexate-ciprofloxacin association should be avoided.

Impact of monitoring plasma 1,1-dichlorodiphenildichloroethane (o,p'DDD) levels on the treatment of patients with adrenocortical carcinoma

BACKGROUND

It has been suggested recently that 1,1-dichlorodiphenildichloroethane (o,p'DDD) elicits a dose effect relation in the treatment of patients with adrenocortical carcinoma (ACC). The authors performed a single-center, prospective study with two major objectives: 1) to confirm the interest of plasma o,p'DDD level measurement as a prognostic factor of response to o,p'DDD therapy; and 2) to look for parameters associated with a therapeutic plasma o,p'DDD level, especially the daily o,p'DDD dose.

METHODS

Since 1995, patients with ACC who were referred to the Gustave-Roussy Institute have been enrolled prospectively in the study. Therapy with o,p'DDD was given as first-line therapy in 13 patients with metastatic disease or as adjuvant therapy in 11 patients. Oral o,p'DDD was given in three separate doses up to at least 6-12 g per day together with substitutive adrenal therapy. Plasma o,p'DDD levels were measured using high-performance liquid chromatography every 2 months. The o,p'DDD therapy was monitored to achieve plasma o,p'DDD levels within 14-20 mg/L. World Health Organization criteria were used to evaluate tumor response and toxicity.

RESULTS

Twenty-four patients with ACC were studied, and a plasma o,p'DDD level > 14 mg/L was achieved in 14 patients (58%). An objective tumor response was observed in four patients with metastatic lesions (31%): One was response was complete, and three were objective hormonal responses. These tumor responses were observed among the six patients who achieved therapeutic plasma o,p'DDD levels. In contrast, no response was observed among the seven patients with plasma o,p'DDD levels that remained consistently low. Eight of 11 patients who received o,p'DDD as adjuvant therapy had disease recurrence, although the plasma o,p'DDD level was > 14 mg/L in 6 patients. Grade 3 or 4 neurologic toxicity was observed in three patients (12%), all with an o,p'DDD level > 20 mg/L. The daily o,p'DDD dose was the only parameter associated with the highest plasma o,p'DDD trough levels: It explained 35% of the variability in the plasma o,p'DDD level. A median interval of 3.7 months was found necessary to achieve the highest o,p'DDD trough levels.

CONCLUSIONS

The results confirm the prognostic impact of the plasma o,p'DDD level in patients with metastatic ACC and its interest in avoiding toxicity.

Pharmacodynamics of tandem high-dose melphalan with peripheral blood stem cell transplantation in children with neuroblastoma and medulloblastoma

Repeated high-dose (HD) chemotherapy with peripheral blood stem cell (PBSC) transplantation is a new modality aimed at increasing both the dose and its intensity in the treatment of chemosensitive tumours. The aim of this study was to evaluate the tolerance, pharmacokinetics (PK) and pharmacodynamics (PD) of HD single-agent melphalan administered over two consecutive courses (C1 and C2) in children. Twenty-one patients (10 girls) with a median age of 4.1 years (range 8 months-14 years) were entered into this study. Five had metastatic neuroblastoma (NB) and 16 a cerebral primitive neuroectodermal tumour (PNET). Melphalan was given at a dose of 100 mg/m(2) every 21 days. PBSCs were infused at a median number of 2.98 x 10(6) CD34(+) cells/kg. Forty courses, ie 21 C1 and 19 C2, were administered. Both courses were well tolerated. The median duration of ANC < 500/microl was 7 and 6 days after C1 and C2, respectively. Platelet recovery (not mandatory to continue the HD strategy) was achieved in 52% of courses. GI toxicity was mild to moderate. The melphalan AUC ranged from 177 to 475 microg small middle dotmin/ml (no difference between C1 and C2). Prolonged neutropenia was associated with a young age (P < 0.001) and a low amount of CFU-GM (P = 0.002). A long time to platelet recovery was associated with a high AUC (P = 0.004) and a young age (P = 0.02). Grade 1 or 2 GI toxicity was associated with a high AUC (P = 0.015). Partial remission was observed in 11/14 patients with measurable cerebral PNET. In conclusion, tandem HD melphalan is feasible and safe in children, and achieved a high response rate in cerebral PNET. The observed PK-PD relationships may help us design PK-guided outpatient treatment.

Phase I trial and pharmacological study of a 3-hour paclitaxel infusion in children with refractory solid tumours: a SFOP study

The maximum tolerated dose of paclitaxel administered by 24-hour continuous infusion in children is known. Short infusion might offer equivalent antitumour efficacy and reduced haematological toxicity, without increasing the allergic risk. Our aims were to determine the maximum tolerated dose and the pharmacokinetics of paclitaxel in children when administered in 3-h infusion every 3 weeks. Patients older than 6 months, younger than 20 years with refractory malignant solid tumours were eligible when they satisfied standard haematological, renal, hepatic and cardiologic inclusion criteria with life expectancy exceeding 8 weeks. Paclitaxel was administered as a 3-hour infusion after premedication (dexamethasone, dexchlorpheniramine). Pharmacokinetic analysis and solvent assays (ethanol, cremophor) were performed during the first course. 20 courses were studied in 17 patients; 4 dosage levels were investigated (240 to 420 mg/m(2)). No dose-limiting haematological toxicity was observed. Severe acute neurological and allergic toxicity was encountered. One treatment-related death occurred just after the infusion at the highest dosage. Delayed peripheral neurotoxicity and moderate allergic reactions were also encountered. Pharmacokinetic analysis showed dose-dependent clearance of paclitaxel and elevated blood ethanol and Cremophor EL levels. Although no limiting haematological toxicity was reached, we do not recommend this paclitaxel schedule in children because of its acute neurological toxicity.

Establishment and characterization of a human adrenocortical carcinoma xenograft model

Adrenocortical carcinomas are rare malignant tumors. They have a poor prognosis, as they are often diagnosed late and are usually resistant to chemotherapy. The lack of a suitable animal model for these tumors has been a major obstacle to the evaluation of new therapeutic agents. The aim of this study was to establish and characterize xenografts of the human adrenocortical carcinoma NCI H295R cell line as a model of adrenocortical carcinoma for future therapeutic trials. This cell line was sc injected (6 x 10(6) cells) into nude mice (n = 20). Solid tumors were locally measurable after 45 days at 90% of the inoculation sites. The xenografts were similar histologically to the original adrenocortical carcinoma from which the cell line was derived. The xenografts precisely reproduced the dysregulation of the insulin-like growth factor (IGF) system [overexpression of the IGF-II and IGF-binding protein-2 (IGFBP-2) genes] typical of adrenocortical carcinoma. Similarly to adrenocortical carcinomas, human IGFBP-2 (but not IGF-II) was secreted in mouse plasma. We analyzed steroid production (cortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, delta4-androstenedione, 11-deoxycortisol, corticosterone, and testosterone). Xenografts produced all three class of steroids, with the preferential production of androgens of the delta4 pathway. The H295R xenograft model is a good model of human adrenocortical carcinoma, as it mimics dysregulation of the IGF system usually found in these tumors. It also produces IGFBP-2 and steroids that can be used as tumor markers. This model may therefore be useful for evaluating therapeutic agents.

[What is new in pediatric oncology?]

The significant progress made in pediatric oncology during recent years has been due to a major breakthrough in the field of molecular biology and the introduction of new therapeutic strategies that take into account both the quality and the duration of life. Molecular biology has already been instrumental in more fully categorizing the 'small round-cell tumor' group, and in reclassifying the 'Ewing family' tumors. It also provides a valuable tool for the prognostic evaluation of neuroblastomas through the analysis of the N-myc oncogene. In addition, it has permitted the identification of the Li-Fraumeni syndrome of predisposition to cancer in the child, thereby raising the problematical ethical issue of communicating relevant information to subjects at risk. Two examples illustrate innovative strategic concepts: 1) Burkitt's lymphoma, or an example of the successful de-intensification of treatment; and 2) brain tumors in young children, regarding which the desire to improve the quality of life has led to innovative attempts to replace radiotherapy by chemotherapy. Considerable progress has been made in the field of neuropsychology, thereby permitting an improved assessment of disorders and a better management of rehabilitation programs. New anti-cancer agents and also chemo- and radiotherapy that spare healthy tissue are also being developed. Gene therapy and molecular biology will play a major role in future therapeutic strategies; and are now at the preclinical trial stage. This significant overall progress leads to a reconsideration of the organizational approach toward treatment of the pediatric patient population suffering from cancer, and a critical assessment of disease management, which should take into account not only the technical aspects of the disease but also familial and social considerations.