Abstract 4717: Final results from the Phase I study of MetMAb, a monovalent antagonist antibody to the receptor Met, dosed as single agent and in combination with bevacizumab in patients with advanced solid malignancies

• Published in: Cancer research (Chicago, Ill.) Vol. 71; no. 8_Supplement; p. 4717
• Main Authors: Moss, Rebecca A., Bothos, John G., Patel, Premal H., Peterson, Amy C., Eppler, Steve, Bai, Shuang, Nijem, Ihsan, Desnoyers, Luc, Kaur, Surinder, Zha, Jiping, Yu, Wei, Simpson, Joe, Ratain, Mark J., Tan, Antoinette R., Stein, Mark N., Mehnert, Janice M., Salgia, Ravi
• Format: Journal Article
• Language: English
• Published: 15-04-2011
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2011-4717

Abstract
Background: The receptor tyrosine kinase Met and/or its ligand, hepatocyte growth factor (HGF), are frequently over-expressed in cancers. Aberrant Met activation can enhance invasion, proliferation, and survival and may promote angiogenesis. MetMAb was uniquely engineered as a recombinant, humanized, monovalent monoclonal antibody to act as an antagonist of HGF-induced Met signaling.
Materials and Methods: This 3+3 dose-escalation study consisted of three phases: 1) dose-escalation evaluating 1, 4, 10, 15, 20 and 30 mg/kg IV Q3W; 2) expansion at 15mg/kg IV Q3W; and 3) combination testing MetMAb, at 10 and 15mg/kg IV Q3W, plus bevacizumab (15mg/kg Q3W). Pre- and post- dose serum was collected for evaluation of pharmacodynamic biomarkers that could be affected by inhibition of Met and/or VEGF signaling.
Results: 43 patients were treated in this study (21 in escalation, 13 in expansion, and 9 in combination). MetMAb has a half-life of approximately 11 days, and there were no apparent PK interactions with bevacizumab. MetMAb was generally well tolerated, both alone and in combination. The most frequent treatment-related adverse events included: fatigue, peripheral edema and hypoalbuminemia. In patients treated with the combination, no Grade 3-5 treatment-related adverse events were reported; a Grade 1, and dose-limiting adverse event of hemoptysis was reported in a patient who had central-necrosis of pulmonary metastases. A patient with gastric carcinoma achieved a complete response after 4 cycles of single-agent MetMAb; this patient came off study after 10 cycles with a sustained complete response.
Conclusions: MetMAb, when administered as a single-agent, or in combination with bevacizumab was generally safe and well tolerated. A Phase II trial testing MetMAb in combination with bevacizumab and paclitaxel in patients with triple negative breast cancer is currently ongoing, while a Phase III trial testing MetMAb in combination with erlotinib in advanced NSCLC patients is planned.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4717. doi:10.1158/1538-7445.AM2011-4717