Dose-specific clearance of TRC105 (anti-CD105 antibody) in advanced solid tumor patients.

3042^ Background: CD105 is an endothelial cell membrane receptor highly expressed on angiogenic tumor vessels. TRC105 is an anti-CD105 monoclonal antibody that inhibits angiogenesis and tumor growth by endothelial cell growth inhibition, ADCC and apoptosis. Methods: Patients with advanced solid tumors and normal organ function were treated with escalating doses of intravenously administered TRC105 and assessed for safety and pharmacokinetics (PK). PK parameters for determining dose-linearity were estimated following single doses on in 16 patients at 3, 10 and 15 mg/kg and correlated with safety. Results: TRC105 was tolerated at 10 mg/kg weekly and 15 mg/kg every 2 weeks, but hyproliferative anemia was dose-limiting at 15 mg/kg weekly and was associated with TRC105 accumulation in serum from target saturation. Preliminary evidence of activity was observed with 21 of 45 evaluable patients progression-free at 2 months, including two ongoing responders. The AUC-single dose relationship of TRC105 revealed supr...