Phase I evaluation of CDP791, a PEGylated di-Fab' conjugate that binds vascular endothelial growth factor receptor 2.

PURPOSE: Specific blocking of vascular endothelial growth factor receptor 2 (VEGFR-2) is a novel therapeutic approach. Here, we report the first phase I clinical trial evaluation of CDP791, a PEGylated di-Fab' conjugate that binds VEGFR-2. EXPERIMENTAL DESIGN: Cohorts of patients received CDP791 at doses between 0.3 and 30 mg/kg every 3 weeks for the initial two doses. RESULTS: The compound was well tolerated with no dose-limiting toxicity. Dose-related hypertension was observed in patients receiving CDP791 10 mg/kg or more and several patients on the higher doses developed infusion-related cutaneous hemangiomata arising 28 to 106 days after the first drug administration and resolving 3 weeks after cessation. Biopsy and histologic evaluation showed that CDP791-bound VEGFR-2 is non-phosphorylated, suggesting that the drug is biologically active. Concentrations of CDP791 considered biologically relevant were sustained for 3 weeks when doses of 10 mg/kg or more were administered. Although no reductions in vascular permeability were recorded using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI), there was a significant dose level-related reduction in tumor growth. While challenging the recent dogma that active VEGF inhibitors should modulate DCE-MRI measurements of vascular permeability, this highlights the potential of serial three-dimensional tumor measurements to detect tumor growth arrest. Twelve patients received drug for more than two treatments, although no partial or complete responses were seen. CONCLUSION: The data show that CDP791 is biologically active and well tolerated, achieving appropriate plasma concentrations when administered at 10 mg/kg or more every 3 weeks.

The neoadjuvant approach in the treatment of patients with advanced epithelial ovarian carcinoma.

AIMS: Ovarian cancer has a very poor prognosis, with 5-year survival rates of 5-20% for advanced-stage disease. This work was designed to verify whether the neoadjuvant approach had an effect on survival in patients with advanced-stage ovarian cancer. MATERIALS AND METHODS: Patients with stage III or IV disease who received neoadjuvant platinum-based chemotherapy (group 1) were compared with a group of conventionally treated patients (group 2). RESULTS: Most of the patients in group 1 (76%) had partial tumoral responses after chemotherapy. Patients from group 1 (n = 42) had a median survival that was not different from that in patients from group 2 (n = 348). Patients who received platinum-based chemotherapy with taxanes had the same survival of patients who received no taxanes. CONCLUSIONS: Our results showed similar responses and survival rates for patients with stage III or IV ovarian cancer treated with neoadjuvant platinum-based chemotherapy, when compared with patients who underwent primary suboptimal cytoreductive surgery. Our data therefore support the ongoing trials to determine the optimum timing of surgery for ovarian cancer.

The interval from surgery to chemotherapy in the treatment of advanced epithelial ovarian carcinoma.

BACKGROUND: To study the effect of the interval between surgery and the start of chemotherapy in the treatment of patients with advanced ovarian cancer. METHODS: We stratified patients according to the start of platinum-based chemotherapy in group 1 (within 4 weeks from surgery), group 2 (between 4 and 8 weeks) and group 3 (between 8 and 12 weeks). RESULTS: Three hundred and ninty-four stage III ovarian cancer patients were analysed. In the multivariate analysis there were no differences in survival according to the interval between surgery and chemotherapy among the three groups. The independent prognostic variables were type of procedure (p = 0.014), performance status (p = 0.040) and post-chemotherapy CA-125 (p < 0.0001). CONCLUSIONS: The interval between surgery and chemotherapy does not affect outcome.

Resistance to anti-VEGF agents.

The number of anti-angiogenic agents developed for clinical use has risen greatly over the past decade. Currently, more than 80 are in trials ranging from phase I through to phase III studies and many more are in preclinical evaluation. Much hope was envisaged for these new agents to become the panacea of anti-tumoural treatment. Unfortunately the single agent activity to date has proven to be disappointing although one trial has recently reported a survival advantage when chemotherapy was administered with anti-VEGF antibodies in the setting of advanced colorectal cancer. To an extent, this may be due to great expectations of cytostatic compounds, but recently many factors have been examined to explain the differences between clinical and experimental findings. In this review, some of the factors responsible for the discrepancy are examined, with a specific focus on inhibitors of VEGF. The key factors responsible for the lack of activity are tumour heterogeneity and redundancy in the VEGF signalling system. An increased understanding of these factors is critical to the development of effective anti-angiogenic agents and need to be taken into account as new generations of drugs emerge.

Seroprevalence and isolation of Toxoplasma gondii from free-range chickens from Espírito Santo state, southeastern Brazil.

Prevalence of Toxoplasma gondii infection in 510 free-range (FR) chickens (380 from 33 small farms, and 130 from a slaughter house for FR chickens) from Espírito Santo state, southeastern Brazil, was investigated. Antibodies to T. gondii were sought using commercial indirect haemagglutination (IHAT, Imuno-HAI Toxo(®), Wama Diagnóstica, São Paulo, Brazil, cut-off 1:16) and the modified agglutination test (MAT, cut-off 1:25) tests. Attempts were made to isolate viable T. gondii from seropositive chickens by bioassay in mice. Pooled samples of brain, heart and quadriceps muscle of one thigh (total 40 g) from 64 chickens with IHAT titers of ≥ 1:16 were minced, digested in pepsin and bioassayed in mice. Antibodies to T. gondii were found in 40.4% (206/510) FR chickens by IHAT (titer ≥ 1:16) and 38.8% (198/510) by MAT (titer ≥ 1:25); concordance between IHAT and MAT was 81.6% (kappa index=0.614). Viable T. gondii was isolated (designated TgCkBr234-281) from 48 of 64 (75%) seropositive (IHAT titers ≥ 1:32) FR chickens. Most isolates of T. gondii were virulent for mice; 100% of mice inoculated with 44 of 48 isolates died of toxoplasmosis within 30 days post inoculation (p.i). An epidemiological investigation revealed that people living in rural areas have little knowledge about the parasite and about the risk of acquiring it from raw meat. Results indicated that the locally available IHAT was useful for screening of chicken sera for T. gondii antibodies.