By Diagnostics World Staff
December 15, 2022 | Personalis and the University of California, San Francisco (UCSF) have announced a collaboration that will deploy a personalized liquid biopsy-based research use only (RUO) assay for a study of patients with colorectal cancer.
The research efforts will use Personalis’ NeXT Personal assay to evaluate circulating tumor DNA (ctDNA)-based signatures associated with treatment response and adverse events in a cohort of late-stage colorectal cancer patients receiving capecitabine (Xeloda) together with pembrolizumab (Keytruda) and bevacizumab (Avastin).
Colorectal cancer is among the top five most prevalent and deadly malignancies worldwide. The efficacy of combined targeted therapy approaches varies widely, reflecting the need for more sophisticated predictive measures. But Personalis asserts that today’s ctDNA assays lack sufficient sensitivity for detecting cfDNA-based biomarkers due to extensive disease heterogeneity, potentially low levels of signal from small metastases, and the wide range of mutational profiles relevant to different types of cancer.
In launching this RUO study, the team hopes to find biomarkers that would help identify which patients will respond to immunotherapy.
“Assessment of early response and adaptive resistance both critically require a non-invasive liquid biopsy-based assay that can confidently detect changes in the abundance and mutational profile of cancer cells. Through serial monitoring of ctDNA, we will develop greater understanding of patient response to therapy and use these data to inform the development of signatures predictive of response,” said Lawrence Fong, MD, the Efim Guzik Distinguished Professor in Cancer Biology at UCSF and leader of the Cancer Immunotherapy Program in a press release.
“The increased sensitivity of NeXT Personal will make it possible to identify complete response/absence of disease and recurrence earlier than existing technologies. Further, by leveraging the plasma sampling in this cohort, we aim to determine optimal sample collection timing for early identification of complete response and demonstrate clinical utility. Additionally, we seek to demonstrate earlier detection of disease recurrence, providing support for future interventional studies that can use this information to make rapid changes to treatment,” said Richard Chen, MD, Chief Medical Officer and Senior Vice President of R&D at Personalis in the same statement.