Specific targeting, biodistribution, and lack of immunogenicity of chimeric anti-GD3 monoclonal antibody KM871 in patients with metastatic melanoma: results of a phase I trial.

PURPOSE: KM871 is a chimeric monoclonal antibody against the ganglioside antigen GD3, which is highly expressed on melanoma cells. We conducted an open-label, dose escalation phase I trial of KM871 in patients with metastatic melanoma. PATIENTS AND METHODS: Seventeen patients were entered onto one of five dose levels (1, 5, 10, 20, and 40 mg/m2). Patients received three infusions of KM871 at 2-week intervals, with the first infusion of KM871 trace-labeled with indium-111 (111In) to enable assessment of biodistribution in vivo. Biopsies of metastatic melanoma sites were performed on days 7 to 10. RESULTS: Fifteen of 17 patients completed a cycle of three infusions of KM871. No dose-limiting toxicity was observed during the trial; the maximum-tolerated dose was therefore not reached. Three patients (at the 1-, 5-, and 40-mg/m2 dose levels) developed pain and/or erythema at tumor sites consistent with an inflammatory response. No normal tissue uptake of 111In-KM871 was observed, and tumor uptake of 111In-KM871 was observed in all lesions greater than 1.5 cm (tumor biopsy 111KM871 uptake results: range, 0.001% to 0.026% injected dose/g). The ratio of maximum tumor to normal tissue was 15:1. Pharmacokinetic analysis revealed a 111In-KM871 terminal half-life of 7.68 +/- 2.94 days. One patient had a clinical partial response that lasted 11 months. There was no serologic evidence of human antichimeric antibody in any patient, including one patient who received 16 infusions over a 12-month period. CONCLUSION: This study is the first to demonstrate the biodistribution and specific targeting of an anti-GD3 antibody to metastatic melanoma in patients. The long half-life and lack of immunogenicity of KM871 makes this antibody an attractive potential therapy for patients with metastatic melanoma.

Prune-belly syndrome: ongoing controversies regarding pathogenesis and management.

Classical prune-belly syndrome (also known as Triad syndrome, Eagle-Barrett syndrome, abdominal muscular deficiency syndrome) consists of a triad of anomalies: deficient abdominal wall musculature, urinary tract dilatation, and cryptorchidism. Although most investigators consider prune-belly syndrome a distinct entity, there is no consensus as to its pathogenesis despite extensive study of clinical cases and pathological material. Prognosis may vary from death in utero to a near-normal life expectancy. The lack of understanding of pathogenesis and wide range of severity result in dilemmas in treatment planning, and surgeons vary widely in their approach. This article discusses prune-belly syndrome, presents the currently favored hypotheses regarding its pathogenesis, and gives an overview of accepted management strategies.

Establishment and characterization of a novel hepatoblastoma-derived cell line.

Hepatoblastoma is the most common pediatric liver cancer, and complete resection is required for long-term survival. There are few reported hepatoblastoma cell lines available for study. In order to develop in vitro and animal models, the authors isolated an additional cell line (HB1) from a human hepatoblastoma and here report its characteristics in culture. Cells were analyzed for growth rate, clonigenicity, and tumorigenicity, using electron microscopy. Immunocytochemistry and Northern analysis for the expression of specific surface markers and genes of interest were also performed. HB1 cells required fetal calf serum but grew well in culture (population doubling time of 2 days) and had an undifferentiated appearance under electron microscopy. Epidermal growth factor (EGF) and hydrocortisone stimulated growth with or without serum, but not autocrine growth stimulation via the epidermal growth factor receptor was detected. Proteins produced by HB1 cells under normal culture conditions included alpha-fetoprotein, cytokeratins 8 and 18, and lactate dehydrogenase (with an isozyme subunit composition similar to that of liver). HB1 cells showed chronic, high expression of c-myc and Ha-ras oncogenes but no N-myc and apparently normal RB gene expression. This cell line shows characteristics in culture consistent with malignant, hepatic epithelial cells and is apparently EGF dependent. It may provide a model system for the future development of alternative therapies.

Slow-transit constipation in childhood.

BACKGROUND/PURPOSE: Intestinal neuronal dysplasia (IND) as a cause for severe chronic constipation remains controversial. The authors have identified a deficiency of substance P (SP) immunoreactivity in the colonic nerve fibres of some children with severe constipation, and aim to correlate this with clinical features and transit studies. METHODS: Over 100 children with intractable constipation with or without soiling have been assessed by clinical questionnaire, nuclear transit study, and laparoscopic seromuscular biopsy of the colon labelled with antibodies to SP and vasoactive intestinal peptide (VIP) using immunofluorescence. RESULTS: More than 30% of children had delayed passage of meconium, and symptoms of constipation appeared by the age of 1 year in 63%. More than 80% had significant delay in colonic transit, and of these, about 80% had reduced SP immunoreactivity in the axons of the colonic circular muscle. A further 6% had heterotopic ganglion cells or hypoplastic ganglia on routine histology. CONCLUSIONS: In children with intractable constipation, features of early onset and delayed colonic transit correlated with deficiency of SP in myenteric axons. The authors propose that deficient SP immunoreactivity may be used as a histological marker for severe constipation. Defective excitatory neuromuscular transmission may be the cause of slow colonic transit.

Management of hepatic epithelial malignancy in childhood and adolescence.

This review addresses the management of epithelial liver tumors of childhood and adolescence (hepatoblastoma and hepatocellular carcinoma), which constitute approximately 90% of primary liver malignancy in this age group. The epidemiology, pathology, clinical presentation, and diagnosis are given in order to appreciate differences in biological behavior of these two neoplasms and the need for a distinct therapeutic approach to each. The multidisciplinary treatment of hepatoblastoma has become increasingly refined and long-term survival can be expected in approximately 80% of patients. Where survival once depended solely on complete surgical resection, it is now also possible in patients with initially unresectable tumors due to effective cytoreductive chemotherapy. The problem of systemic relapse following complete surgical resection has been reduced although not eliminated by adjuvant chemotherapy programs. To date, the biological behavior of hepatocellular carcinoma prohibits complete resection in the majority of children and chemotherapy has not been effective. Early detection, development of new agents and techniques such as monoclonal antibodies and total hepatectomy with autologous transplantation in selected cases may offer hope for the future.

Liver regeneration in children after major hepatectomy for malignancy--evaluation using a computer-aided technique of volume measurement.

PURPOSE: The time course of hepatic volume regeneration and return of excretory and synthetic function was studied in eight children undergoing lobar or extended lobar liver resections for hepatoblastoma (n = 5), hepatoma (n = 1), and recurrent nephroblastoma (n = 2). Five patients received preoperative and all were administered postoperative chemotherapy. Whole-liver irradiation was administered to one patient. One additional patient who underwent an extended hepatic resection for benign disease and did not receive chemotherapy was included for comparison. METHODS: A previously validated technique of computer-aided volume measurement was used to measure liver volumes from serial CT scans obtained after hepatic surgery. Normal liver volume as a function of age was determined from the literature and the time course of regeneration was compared to normal liver growth. Postoperative serum albumin, total bilirubin, serum glutamic oxaloacetic transaminase, and alkaline phosphatase levels were recorded and correlated with volume regeneration. RESULTS: In six patients hepatic regeneration had progressed to normal volume by 90 days after resection (normal volume for age was achieved by 50 days in three patients). There was an initial rapid rate of regeneration (> 10 cc/day) which declined to a normal rate of less than 0.5 cc/day at 90 days after surgery. Two children with failure to thrive displayed the same pattern of rapid regeneration, attaining a volume appropriate for weight but less than that expected for age. The shape of the liver volume regeneration curve was similar in one additional patient undergoing an extended left lobectomy for benign disease. A brief rise in bilirubin occurred during the first week and a transient fall in serum albumin was followed by resumption of normal synthetic capacity within 6 weeks in all but two patients. CONCLUSIONS: Liver regeneration in children is a rapid process occurring despite the administration of cytotoxic agents and hepatic irradiation.

Validation of a technique of computer-aided tumor volume determination.

Tumor volume at diagnosis is an important prognostic factor and volume change may predict therapeutic response. However, the accuracy of in vivo tumor volume measurement has not been established. The purpose of this study was validation of a personal computer-based technique of in vivo volume determination. CT scans of 8 radiological phantoms and 25 neuroblastoma patients were digitized using three-dimensional reconstruction and volume determination software. Phantom volumes were calculated from known dimensions or direct measurement while tumor volumes were determined by water displacement at the time of complete gross resection. Comparison to tumor volume determination was performed using an ellipsoid geometric model. The standard deviation for computer-generated triplicate volume determinations varied from 0.1 to 5.6 cc (median = 0.6 cc). Linear regression analysis demonstrated a close correlation between computer-derived volumes and the volume measured at surgery (r = 0.99) with small variability. In contrast, the correlation coefficient between ellipsoid formula-derived and water displacement volumes was 0.93. Computer-generated tumor volume determination is reproducible, accurate, and easily obtained from hard copy scans. This technique provides a quantitative in vivo measurement for use as a prognostic or therapeutic response variable.