Liquid biopsy has become a useful tool for targeted cancer treatment selection. It also has immense potential as a monitoring tool for the emergence of treatment resistance. 

To advance this potential, Canexia Health is collaborating with Exactis Innovation on a clinical study to monitor plasma circulating tumor DNA (ctDNA) in metastatic colorectal cancer patients using Canexia’s Follow It® assay to detect changes in mutations and disease progression. Exactis Innovation is a Canadian National Centre of Excellence in Personalized Medicine comprising a network of 16 oncology centers bringing together public and private partners focusing on precision oncology.

Study objectives included:

  • Using a retrospective collection of 55 metastatic colorectal cancer patients enrolled on a clinical trial to determine if longitudinal plasma ctDNA mutation monitoring can aid in predicting clinical progression prior to standard of care CT imaging
  • Identifying resistance mechanisms in patients undergoing therapy
  • Establishing Canexia’s Follow It assay as a liquid biopsy tool to assess disease progression over time in metastatic colorectal cancer patients

Among the findings:

  • PIK3CA mutations are significantly enriched in treatment resistance patients and thus may be a resistance mechanism in this mCRC cohort
  • KRAS and PIK3CA are enriched as co-mutated in the resistance population
  • RAS wildtype patients often harborTP53 mutations that can be used for ctDNA monitoring
  • In the metastatic setting, Follow It detects CRC driver ctDNA mutations in serial longitudinal patient plasma samples within a clinical trial


Recent Resources


May 15, 2023

Poster sessions at AACR: a recap

We were grateful for the opportunity to attend and present at the AACR Annual Meeting last week, where three of our scientists highlighted some of the exciting work happening in our Vancouver lab.