Patient-reported outcomes at discontinuation of anti-angiogenesis therapy in the randomized trial of chemotherapy with bevacizumab for advanced cervical cancer: an NRG Oncology Group study.

INTRODUCTION: To describe patient-reported outcomes and toxicities at time of treatment discontinuation secondary to progression or toxicities in advanced/recurrent cervical cancer patients receiving chemotherapy with bevacizumab. METHODS: Summarize toxicity, grade, and health-related quality of life within 1 month of treatment discontinuation for women receiving chemotherapy with bevacizumab in GOG240. RESULTS: Of the 227 patients who received chemotherapy with bevacizumab, 148 discontinued study protocol treatment (90 for disease progression and 58 for toxicity). The median survival time from treatment discontinuation to death was 7.9 months (95% CI 5.0 to 9.0) for those who progressed versus 12.1 months (95% CI 8.9 to 23.2) for those who discontinued therapy due to toxicities. The most common grade 3 or higher toxicities included hematologic, gastrointestinal, and pain. Some 57% (84/148) of patients completed quality of life assessment within 1 month of treatment discontinuation. Those patients who discontinued treatment due to progression had a mean decline in the FACT-Cx TOI of 3.2 points versus 2.2 in patients who discontinued therapy due to toxicity. This was a 9.9 point greater decline in the FACT-Cx TOI scores than those who discontinued treatment due to progression (95% CI 2.8 to 17.0, p=0.007). The decline in quality of life was due to worsening physical and functional well-being. Those who discontinued treatment due to toxicities had worse neurotoxicity and pain. DISCUSSION: Patients who discontinued chemotherapy with bevacizumab for toxicity experienced longer post-protocol survival but significantly greater declination in quality of life than those with progression. Future trial design should include supportive care interventions that optimize physiologic function and performance status for salvage therapies.

A novel model for evaluating therapies targeting human tumor vasculature and human cancer stem-like cells.

Human tumor vessels express tumor vascular markers (TVM), proteins that are not expressed in normal blood vessels. Antibodies targeting TVMs could act as potent therapeutics. Unfortunately, preclinical in vivo studies testing anti-human TVM therapies have been difficult to do due to a lack of in vivo models with confirmed expression of human TVMs. We therefore evaluated TVM expression in a human embryonic stem cell-derived teratoma (hESCT) tumor model previously shown to have human vessels. We now report that in the presence of tumor cells, hESCT tumor vessels express human TVMs. The addition of mouse embryonic fibroblasts and human tumor endothelial cells significantly increases the number of human tumor vessels. TVM induction is mostly tumor-type-specific with ovarian cancer cells inducing primarily ovarian TVMs, whereas breast cancer cells induce breast cancer specific TVMs. We show the use of this model to test an anti-human specific TVM immunotherapeutics; anti-human Thy1 TVM immunotherapy results in central tumor necrosis and a three-fold reduction in human tumor vascular density. Finally, we tested the ability of the hESCT model, with human tumor vascular niche, to enhance the engraftment rate of primary human ovarian cancer stem-like cells (CSC). ALDH(+) CSC from patients (n = 6) engrafted in hESCT within 4 to 12 weeks whereas none engrafted in the flank. ALDH(-) ovarian cancer cells showed no engraftment in the hESCT or flank (n = 3). Thus, this model represents a useful tool to test anti-human TVM therapy and evaluate in vivo human CSC tumor biology.

Identifying alemtuzumab as an anti-myeloid cell antiangiogenic therapy for the treatment of ovarian cancer.

BACKGROUND: Murine studies suggest that myeloid cells such as vascular leukocytes (VLC) and Tie2+ monocytes play a critical role in tumor angiogenesis and vasculogenesis. Myeloid cells are a primary cause of resistance to anti-VEGF therapy. The elimination of these cells from the tumor microenvironment significantly restricts tumor growth in both spontaneous and xenograft murine tumor models. Thus animal studies indicate that myeloid cells are potential therapeutic targets for solid tumor therapy. Abundant VLC and Tie2+ monocytes have been reported in human cancer. Unfortunately, the importance of VLC in human cancer growth remains untested as there are no confirmed therapeutics to target human VLC. METHODS: We used FACS to analyze VLC in ovarian and non-ovarian tumors, and characterize the relationship of VLC and Tie2-monocytes. We performed qRT-PCR and FACS on human VLC to assess the expression of the CD52 antigen, the target of the immunotherapeutic Alemtuzumab. We assessed Alemtuzumab's ability to induce complement-mediated VLC killing in vitro and in human tumor ascites. Finally we assessed the impact of anti-CD52 immuno-toxin therapy on murine ovarian tumor growth. RESULTS: Human VLC are present in ovarian and non-ovarian tumors. The majority of VLC appear to be Tie2+ monocytes. VLC and Tie2+ monocytes express high levels of CD52, the target of the immunotherapeutic Alemtuzumab. Alemtuzumab potently induces complement-mediated lysis of VLC in vitro and ex-vivo in ovarian tumor ascites. Anti-CD52 immunotherapy targeting VLC restricts tumor angiogenesis and growth in murine ovarian cancer. CONCLUSION: These studies confirm VLC/myeloid cells as therapeutic targets in ovarian cancer. Our data provide critical pre-clinical evidence supporting the use of Alemtuzumab in clinical trials to test its efficacy as an anti-myeloid cell antiangiogenic therapeutic in ovarian cancer. The identification of an FDA approved anti-VLC agent with a history of clinical use will allow immediate proof-of-principle clinical trials in patients with ovarian cancer.