Sunitinib is active in patients with heavily pretreated MBC. Most AEs were of mild-to-moderate severity and manageable with supportive treatment and/or dose modification. Further studies in breast cancer are warranted.

Purpose TRC105 is a chimeric IgG1 monoclonal antibody that binds CD105 (endoglin). This first-in-human, phase 1, open label study assessed safety, pharmacokinetics, and antitumor activity of TRC105 in patients with advanced refractory solid tumors. Patients and Methods Patients received escalating doses of intravenous TRC105 until disease progression or unacceptable toxicity using a standard 3 + 3 phase 1 design. Results Fifty patients were treated with escalating doses of TRC105. The maximum tolerated dose was exceeded at 15 mg/kg every week due to dose-limiting hypoproliferative anemia. TRC105 exposure increased with increasing dose, and continuous serum concentrations that saturate CD105 receptors were maintained at 10 mg/kg weekly (the maximum tolerated dose) and 15 mg/kg every 2 weeks. Common adverse events including anemia, telangiectasias and infusion reactions reflected the mechanism of action of the drug. Antibodies to TRC105 were not detected in patients treated with TRC105 from Chinese hamster ovary cells being used in ongoing phase 1b and phase 2 studies. Stable disease or better was achieved in 21 of 45 evaluable patients (47%) including two ongoing responses at 48 and 18 months. Conclusion TRC105 was tolerated at 10 mg/kg every week and 15 mg/kg every 2 weeks with a safety profile that was distinct from that of VEGF inhibitors. Evidence of clinical activity was seen in a refractory patient population. Ongoing clinical trials are testing TRC105 in combination with chemotherapy and VEGF inhibitors and as a single agent in prostate, ovarian, bladder, and hepatocellular cancer.

specimen revealed a tumour mass with histologic features of pronounced osteogenesis and no more evidence of gctb. This case demonstrated a major tumour response to denosumab in the neoadjuvant setting, with a complete pathologic response.Is denosumab a breakthrough in the treatment of gctb? We reviewed the literature focusing on denosumab and gctb, and here we discuss the biggest questions related to the future management of gctb. GIANT CELL TUMOUR OF BONEAs one type of giant-cell-rich lesion of bone, gctb is characterized by the presence of numerous multinucleated osteoclast-type giant cells, and in this mesenchymal tumour, the mononuclear stromal cells are the neoplastic cell type 2 . The giant cells have been confirmed to express rankl and are responsible for the aggressive osteolytic nature of the tumour 3 . Although generally benign, atypical gctb may be associated with multiple local recurrences, multicentricity, pulmonary metastases, or lesions that cannot be removed surgically without causing substantial morbidity 4 . The World Health Organization therefore classifies gctb as "an aggressive, potentially malignant lesion" 5 .In the United States, gctb accounts for approximately 5% of all primary bone tumours and 20% of all benign bone tumours in adults 6 . About 50−60 new cases of gctb are managed by specialist health care services each year in the United Kingdom 7 . The disease is more common in China and India, where it constitutes approximately 20% of all primary bone tumours 5 . Giant cell tumour of bone occurs most commonly during the second to fourth decades of life (60%-75%) and has a maleto-female ratio in the range 1:1.2 to 1:1.5 2,5 . Most lesions develop in the long bones (75%-90%), with most cases (50%-65%) occurring near the knee 1,2,8 . Other frequent sites are the distal radius, proximal humerus, fibula, sacrum, and vertebral body (fewer than 3% of cases) 2,8 . In no reported case has gctb ABSTRACT Giant cell tumour of bone (gctb) is one type of giantcell-rich bone lesion characterized by the presence of numerous multinucleated osteoclast-type giant cells. Giant cells are known to express rankl (receptor activator of nuclear factor κB ligand) and are responsible for the aggressive osteolytic nature of the tumour. No available treatment option is definitively effective in curing this disease, especially in surgically unsalvageable cases. In recent years, several studies of denosumab in patients with advanced or unresectable gctb have shown objective changes in tumour composition, reduced bony destruction, and clinical benefit.Denosumab is a fully human monoclonal antibody that targets and binds with high affinity and specificity to rankl. Several large phase iii studies have shown that denosumab is more effective than bisphosphonates in reducing skeletal morbidity arising from a wide range of tumours and that it can delay bone metastasis. The relevant articles are reviewed here. The controversies related to the future use of denosumab in the treatment of gctb are discussed. KEY WORDSDenosuma...

Purpose Endoglin, an endothelial cell membrane receptor expressed on angiogenic tumor vessels, is essential for angiogenesis and upregulated in the setting of VEGF inhibition. TRC105 is an anti-endoglin IgG1 monoclonal antibody that potentiates VEGF inhibitors in preclinical models. This study assessed safety, pharmacokinetics, and anti-tumor activity of TRC105 in combination with bevacizumab. Patients and Methods Patients (n=38) with advanced solid tumors, Eastern Cooperative Group performance status 0–1, and normal organ function were treated with escalating doses of TRC105 plus bevacizumab until disease progression or unacceptable toxicity using a standard 3 + 3 phase 1 design. Results TRC105 and bevacizumab were well tolerated at their recommended single agent doses (10 mg/kg) when the initial dose of TRC105 was delayed by one week and divided over two days to limit the frequency of headache. The concurrent administration of bevacizumab and TRC105 did not otherwise potentiate known toxicities of TRC105 or bevacizumab. Hypertension and proteinuria were observed, though not at rates expected for single agent bevacizumab. Several patients who had previously progressed on bevacizumab or VEGF receptor tyrosine kinase inhibitor (VEGFR TKI) treatment experienced reductions in tumor volume, including two partial responses by RECIST, and six remained without progression for longer periods than during their prior VEGF inhibitor therapy. Conclusion TRC105 was well tolerated with bevacizumab and clinical activity was observed in a VEGF inhibitor refractory population. Ongoing clinical trials are testing TRC105 in combination with bevacizumab in glioblastoma, and with VEGFR TKIs in renal cell carcinoma, hepatocellular carcinoma, and soft tissue sarcoma.

TRC105 is an endoglin-targeting drug that possesses anti-angiogenic and antitumor potential. Analysis of the initial phase I trial of TRC105 demonstrated good tolerability and efficacy in cancer patients. In this report, we analyzed multiple circulating biomarkers at baseline, cycle 2 day 1 (C2D1), and end of study (EOS) for each patient. The baseline level and the fold change from baseline to both C2D1 and EOS for each marker were statistically analyzed. At C2D1, seven markers were significantly downregulated (angiopoietin-2 [Ang-2], insulin-like growth factor-binding protein-3 [IGFBP-3], plasminogen activator inhibitor-1 [PAI-1] total, platelet-derived growth factor [PDGF]-AA, PDGF-BB, thrombospondin-1 [TSP-1], and vascular endothelial growth factor [VEGF]-D). Meanwhile, seven markers were upregulated by C2D1 (E-Cadherin, soluble Endoglin [sEnd], E-Selectin, interleukin-6 [IL-6], osteopontin [OPN], TSP-2, and von Willebrand factor [vWF]). At EOS, seven markers were upregulated including Ang-2, C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), IGFBP-1, IL-6, TSP-2, and vascular cell adhesion molecule-1 (VCAM-1). A statistical trend was also seen for increases of VEGF-A and placenta growth factor (PlGF) at EOS. Throughout treatment, sEnd levels significantly increased, an observation that was recapitulated in cultured endothelial cells. This is the first report of plasma-based biomarkers in patients receiving TRC105. TRC105 treatment by C2D1 was associated with decreases in several angiogenic factors, including Ang-2, PDGF isoforms, and VEGF isoforms, offering insight into the mechanisms underlying TRC105's anti-angiogenic, antitumor function. Increases in sEnd were the most significant of all observed biomarker changes and may reflect direct drug effects. Additionally, biomarker changes in response to TRC105 are distinct from those seen in patients treated with VEGF-targeting drugs, suggesting the possible utility of combining these two classes of angiogenesis inhibitors in patients.

NCT00118898.

No abstract

TRC105 is an anti-endoglin antibody currently being tested in combination with VEGF inhibitors. In the phase Ib trial, 38 patients were treated with both TRC105 and bevacizumab (BEV), and improved clinical outcomes were observed, despite the fact that 30 patients (79%) were refractory to prior anti-VEGF therapy. Plasma samples were tested for angiogenic and inflammatory biomarkers at baseline and on-treatment. To provide broader context of this combination biomarker study, direct cross-study comparisons were made to biomarker studies previously conducted in patients treated with either BEV or TRC105 monotherapy. Upon treatment with BEV and TRC105, pharmacodynamic changes in response to both BEV (PlGF increase) and TRC105 (soluble endoglin increase) were noted. In addition, distinct patterns of change were identified (similar, opposing, neutralizing). Similar patterns were observed when the combination elicited similar effects to those observed with monotherapy treatment (i.e., decreases of Ang-2, increases of IL6 and VCAM-1). Opposing patterns were observed when the combination led to opposing effects compared with monotherapy treatment (i.e., TGFβ1, PDGF-AA and PDGF-BB, PAI-1). Lastly, neutralizing patterns were observed when one drug led to increase, whereas the other drug led to decrease, and the combination elicited no overall effect on the marker (i.e., VEGF-A, VEGF-D, and IGFBP-3). Patients achieving partial responses or stable disease from the combination exhibited significantly lower expression of E-Cadherin, HGF, ICAM-1, and TSP-2 at baseline. Taken together, the novel biomarker modulations identified may deepen our understanding of the underlying biology in patients treated with BEV and TRC105 compared with either drug alone. .