Safety and efficacy of cobimetinib (cobi) and atezolizumab (atezo) in a Phase 1b study of metastatic colorectal cancer (mCRC)

Date 29 June 2016
Event ESMO World Congress on Gastrointestinal Cancer 2016
Session ESMO World Congress on Gastrointestinal Cancer 2016 - Abstracts book
Presenter J. Bendell
Citation Annals of Oncology (2016) 27 (2): 1-3. 10.1093/annonc/mdw237
Authors J. Bendell1, K. Tae Won2, C. Cheng Ean3, B. Yung-Jue4, C. Lee5, J. Desai6, J. Lewin7, J. Wallin8, M. Das Thakur8, G. Mwawasi8, E. Cha8, J. Infante1
  • 1Sarah Cannon Research Institute/Tennessee Oncology, Nashville, TN, USA, /
  • 2Asan Medical Center, Seoul, South Korea, /
  • 3Cancer Science Institute of Singapore, National University of Singapore, Singapore, /
  • 4Seoul National University Hospital, Seoul, South Korea, /
  • 5UNC Lineberger Comprehensive Cancer Center, University of North Carolina – Chapel Hill, North Carolina, USA, /
  • 6Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia, /
  • 7Princess Margaret Cancer Center, University Health Network, Toronto, Canada, /
  • 8Genentech, Inc., South San Francisco, CA, USA, /


Microsatellite instability-high (MSI-H) colorectal cancers are associated with high mutation burden and are responsive to PD-L1/PD-1 blockade. However, the majority of mCRC pts are MSS and have lower response rates to PD-L1/PD-1 blockade. Although MEK inhibition has minimal activity in mCRC, preclinical models demonstrate intratumoral T cell accumulation with MEK inhibition and durable tumor regression when combined with anti-PDL1. Therefore, we evaluated the combination of cobi (MEK inhibitor) and atezo (anti-PDL1) in patients (pts) with mCRC.