Complications of a temozolomide overdose: a case report.

PURPOSE AND BACKGROUND: This is a report of a 53 year-old man with a glioblastoma multiforme (GBM) treated with an excessive dose of temozolomide (TMZ). METHODS: This is a single case review of all clinically relevant records. O6-methylguanine-DNA methyltransferase activity was determined by a biochemical assay. RESULTS: Following conventional radiotherapy (RT) without concurrent chemotherapy, the patient received 5,500 mg of TMZ over 2 days. At the standard dose of 200 mg/m2/day his total 5-day dose should have been 1,940 mg. Acutely he had nausea, vomiting and diarrhea for 2 days which cleared. The dominant severe toxicity was pancytopenia between one and four weeks after TMZ which was complicated by secondary infections that were successfully managed. Transient transaminitis occurred but there were no significant pulmonary, renal or other systemic toxicities. His progression free survival was 22 months and overall survival 24 months. CONCLUSION: His outcome suggests that TMZ may prove to be a good agent for dose-escalation trials with hematopoietic stem cell rescue.

A mouse-based strategy for cyclophosphamide pharmacogenomic discovery.

Genome-wide mapping approaches are needed to more fully understand the genetic basis of chemotherapy response. Because of technical and ethical limitations, cancer pharmacogenomics has not yet benefited from traditional robust familial genetic strategies. We have therefore explored the use of the inbred mouse as a genetic model system in which to study response to the cytotoxic agent cyclophosphamide. Multiple phenotypes have been assessed in response to cyclophosphamide in up to 19 inbred mouse strains, including in vitro hematopoietic progenitor cell toxicity and the mobilization of hematopoietic progenitor cells into peripheral blood. Hematopoietic progenitor cell toxicity in vitro varied 2-fold among strains, whereas in vivo progenitor cell mobilization varied almost 75-fold among strains. Males mobilized more hematopoietic progenitor cells than did females, and the low-mobilization phenotype was dominant to the high-mobilization phenotype in F1 hybrid animals. In an initial attempt to analyze candidate genes, genetic variation was assessed in three cytochrome P-450 genes involved in the metabolism of cyclophosphamide. Resequencing of eight strains identified 26 polymorphisms in these genes that may influence response to cyclophosphamide. Distinct regions of high- and low-polymorphism rates were identified, and two common haplotypes were shared among the strains for each gene that exhibited variation. This phenotypic and genotypic variation among inbred strains provides a framework for cyclophosphamide pharmacogenomic discovery.

High-dose melphalan with autotransplantation for refractory multiple myeloma: results of a Southwest Oncology Group phase II trial.

PURPOSE: To evaluate high-dose melphalan followed by autologous stem-cell transplantation in patients with refractory multiple myeloma. PATIENTS AND METHODS: Multiple myeloma patients with alkylating agent or vincristine/doxorubicin/dexamethasone-refractory disease were eligible for the phase II multi-institutional Southwest Oncology Group trial S8993. Patients up to age 70 years were enrolled between April 15, 1991, and May 1, 1996. Patients without prior stem-cell collection were primed with high-dose cyclophosphamide (HD-CTX; 6 g/m(2)) and granulocyte-macrophage colony-stimulating factor. After stem-cell procurement, patients received melphalan 200 mg/m(2) with autologous transplantation. Upon recovery from melphalan, patients were to receive interferon alfa-2b until relapse. RESULTS: Seventy-two patients were enrolled onto S8993; five were ineligible and one received no therapy. Of the 66 assessable patients, 56 patients underwent the transplant procedure; 54 were assessable for response and 56 for toxicity. The response to HD-CTX (n = 37) included three complete remissions (CRs; 8%) and five partial remissions (PR; 14%); response to melphalan (n = 54) included 16 CRs (30%) and 19 PRs (35%), for an overall CR and >/= PR (n = 66; intent-to-treat) of 27% and 58%, respectively. Toxicities included six treatment-related deaths: two during HD-CTX and four during transplantation. The median progression-free survival (PFS) and overall survival (OS) durations on an intent-to-treat basis from transplant registration was 11 months and 19 months (95% confidence interval, 14 to 29 months), respectively. The 3-year actuarial PFS and OS rates were 25% and 31%, respectively. CONCLUSION: High-dose therapy with melphalan 200 mg/m(2) is feasible with high response rates (58% overall) and an OS of 19 months in patients with refractory multiple myeloma.