Biomedical subjects

Lars M Wagner

Publications and source records attributed to Lars M Wagner.

6 recordsLinked to original sources

PubMed2007

Temozolomide and intravenous irinotecan for treatment of advanced Ewing sarcoma.

BACKGROUND: Preclinical models show sequence-dependent synergy with the combination of temozolomide and irinotecan, and a Phase I trial has demonstrated the combination to be tolerable and active in children with relapsed solid tumors. Because responses were seen in patients with Ewing sarcoma (ES) on that trial, additional patients were treated with this combination following study completion. PROCEDURE: We reviewed data from all ES patients treated with temozolomide and irinotecan at four institutions, including seven patients treated on the above Phase I trial. RESULTS: Sixteen patients received a total of 95 courses, with a median of five courses per patient. All patients had either progressive disease (PD) during initial therapy (n = 5) or relapse within 2 years of diagnosis (n = 11). Twelve patients had metastatic disease at diagnosis, including 5 with bone and/or marrow metastases. Patients received oral temozolomide 100 mg/m(2)/day on days 1-5 plus intravenous irinotecan 10-20 mg/m(2)/day on days 1-5 and 8-12, with courses repeated every 21-28 days. We observed 1 complete, 3 partial, and 3 minor responses in 14 evaluable patients, with a median duration of response of 30 weeks. Planned 21-day courses were tolerable and no more toxic than 28-day courses. Myelosuppression was minimal despite heavy pretreatment. Grade 3-4 diarrhea occurred in 11% of courses and was related to higher irinotecan doses. Over 600 irinotecan doses were administered uneventfully at home. CONCLUSIONS: Temozolomide and protracted intravenous irinotecan given in 21-day courses was tolerable and active in patients with advanced ES. Home administration of irinotecan with temozolomide was safe and is reasonable palliative therapy. A formal Phase II study using a uniform dose and schedule is warranted to better define activity.

Administration, Oral↗

PubMed2006

Pilot study to evaluate MYCN expression as a neuroblastoma cell marker to detect minimal residual disease by RT-PCR.

This pilot study was performed to determine whether MYCN expression warrants further investigation as a tumor marker to detect low levels of residual neuroblastoma (NB). Seven NB cell lines and 30 bone marrow (BM) samples from patients with high-risk NB were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) for MYCN expression, and for the established NB marker tyrosine hydroxylase. MYCN was expressed in all 7 NB cell lines, but not in normal peripheral blood, CD34 cells, or BM. In dilution studies using cell lines with or without DNA amplification of MYCN, 1 NB cell in 10 to 10 nucleated blood cells was detectable by RT-PCR. MYCN was identified in all 21 BM samples in which tumor cells were identified by histologic examination, including 4 samples in which tyrosine hydroxylase was not detected. Additionally, expression of both markers was detected in 5 samples that were negative by histology but presumably contained low levels of tumor cells, consistent with the greater sensitivity of RT-PCR compared with morphologic methods. Detection of MYCN RNA was independent of MYCN DNA amplification status. The selective expression of MYCN in tumor cells, and the sensitivity of detection of MYCN by RT-PCR noted in this and other studies, supports further evaluation of MYCN as a NB marker for molecular detection of minimal residual disease.

Biomarkers, Tumor↗

PubMed2004

Combined use of erythropoietin and granulocyte colony-stimulating factor does not decrease blood transfusion requirements during induction therapy for high-risk neuroblastoma: a randomized controlled trial.

PURPOSE: To evaluate the efficacy of recombinant erythropoietin (EPO) and granulocyte colony-stimulating factor (G-CSF) in reducing blood transfusion requirements and stimulating hematopoiesis in children with high-risk neuroblastoma. PATIENTS AND METHODS: Thirty-eight patients given six cycles of intensive induction chemotherapy for high-risk neuroblastoma were randomized to receive G-CSF (n = 20) or G-CSF + EPO (n = 18). Cytokines were given subcutaneously each day, starting 24 hours after each chemotherapy cycle and continuing until 48 hours before the start of the next cycle. The primary end point was the effect of EPO on total red cell transfusion requirements during induction therapy. RESULTS: Patients who received G-CSF + EPO had a higher red cell transfusion requirement (median, 161.0 mL/kg) than did those who received G-CSF alone (median, 106.6 mL/kg; P =.005). In addition, among patients given transfusions for hemoglobin < or = 8 g/dL, those in the G-CSF + EPO group received more red cell transfusions than did those given G-CSF alone (median per patient, 10 v 8, respectively; P =.044). The two treatment groups had similar cumulative durations of neutropenia, incidences of febrile neutropenia, platelet transfusion requirements, and numbers of platelet transfusions; they also received induction chemotherapy for similar durations and had similar probabilities of progression-free survival and overall survival. CONCLUSION: The addition of EPO to the G-CSF regimen provides no benefit for patients receiving intensive induction chemotherapy for high-risk neuroblastoma.

Adolescent↗

PubMed2004

Phase I trial of temozolomide and protracted irinotecan in pediatric patients with refractory solid tumors.

PURPOSE: The purpose is to estimate the maximum-tolerated dose (MTD) of temozolomide and irinotecan given on a protracted schedule in 28-day courses to pediatric patients with refractory solid tumors. EXPERIMENTAL DESIGN: Twelve heavily pretreated patients received 56 courses of oral temozolomide at 100 mg/m(2)/day for 5 days combined with i.v. irinotecan given daily for 5 days for 2 consecutive weeks at either 10 mg/m(2)/day (n = 6) or 15 mg/m(2)/day (n = 6). We assessed toxicity, the pharmacokinetics of temozolomide and irinotecan, and the DNA repair phenotype in tumor samples. RESULTS: Two patients experienced dose-limiting toxicity (DLT) at the higher dose level; one had grade 4 diarrhea, whereas the other had bacteremia with grade 2 neutropenia. In contrast, no patient receiving temozolomide and 10 mg/m(2)/day irinotecan experienced DLT. Myelosuppression was minimal and noncumulative. No pharmacokinetic interaction was observed. Drug metabolite exposures at the MTD were similar to exposures previously associated with single-agent antitumor activity. One complete response, two partial responses, and one minor response were observed in Ewing's sarcoma and neuroblastoma patients previously treated with stem cell transplant. Responding patients had low or absent O(6)-methylguanine-DNA methyltransferase expression in tumor tissue. CONCLUSIONS: The MTD using this schedule was temozolomide (100 mg/m(2)/day) and irinotecan (10 mg/m(2)/day), with DLT being diarrhea and infection. Drug clearance was similar to single-agent values, and clinically relevant SN-38 lactone and MTIC exposures were achieved at the MTD. As predicted by xenograft models, this combination and schedule appears to be tolerable and active in pediatric solid tumors. Evaluation of a 21-day schedule is planned.

Adolescent↗

PubMed2004

Spinal cord schwannomas mimicking drop metastases in a patient with intramedullary ependymoma and neurofibromatosis 2.

The authors describe a 9-year-old boy with a large spinal cord ependymoma whose apparent drop metastases on imaging studies were later demonstrated to be schwannomas. This finding led to the discovery of small bilateral acoustic neuromas and an intracranial meningioma, establishing the diagnosis of neurofibromatosis 2. The presence of additional radiographic abnormalities in a patient with a spinal cord tumor should prompt careful consideration of the diagnosis of neurofibromatosis 2, as early identification of this disorder may significantly affect patient management.

Child↗

PubMed2002

Efficacy and toxicity of a virus-directed enzyme prodrug therapy purging method: preclinical assessment and application to bone marrow samples from neuroblastoma patients.

Autologous stem cell transplantation is used to rescue cancer patients from myelosuppression caused by high-dose chemotherapy. However, autologous grafts often contain tumor cells that can contribute directly to relapse. Current purging methods are useful when fewer than 1% tumor cells contaminate the bone marrow, and patients with tumor burdens of >1% are considered ineligible for chemotherapy that necessitates stem cell rescue. Using neuroblastoma (NB) as a model system, we developed a method that is effective even with tumor burdens of 10-25%. Mixtures of NB-1691 NB cells and CD34(+) hematopoietic cells purged by this method showed no evidence of viable tumor cells as assessed by clonogenic assays or reverse transcription-PCR for the NB cell markers tyrosine hydroxylase and N-MYC. The efficacy and lack of toxicity of the method were verified using in vivo mouse models. Severe combined immunodeficient mice that received purged cell preparations containing 10% NB-1691 cells survived without evidence of disease for the observation period (>1 year), whereas mice that received unpurged cells developed disseminated disease requiring euthanasia 73-96 days after injection of cells. No evidence of toxicity to the mice was detected by numerous laboratory values for bone marrow, liver, and kidney function, and no difference was seen in the ability of purged cell mixtures versus unmanipulated CD34(+) cells to reconstitute the marrow of non-obese diabetic severe combined immunodeficient mice. In a pilot study, marrow was obtained from eight patients who had >/=1% metastatic tumor burden. All eight samples were purged to the level of detection by reverse transcription-PCR (samples from seven patients) or clonogenic potential (sample from one patient), whichever assay was used. The described adenovirus/rabbit carboxylesterase/CPT-11 (irinotecan, 7-ethyl-10[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin) virus-directed enzyme prodrug method may be useful for patients whose tumor burdens exceed 1% at the time of stem cell harvest. Assessment of purging efficacy with additional samples from NB patients is ongoing.

Adenoviridae↗