To demonstrate the clinical utility of using a quantitative CSF tumor cell assay to track progression and treatment response in patients with leptomeningeal disease (LMD).

LMD is a late-stage complication occurring in at least 5-15% of patients with solid tumors. Improved options for identification, treatment and monitoring of LMD are needed, as imaging and cytology assessment have lower sensitivity, specificity, and reliability. Recently, different assays that can detect tumor cells in the CSF and serum have become available that demonstrate an increased sensitivity and specificity compared to cytology, as well as the ability to identify actionable biomarkers expressed by the CSF tumor cells. 

Multiple patients with LMD were longitudinally followed post diagnosis while on various modalities of treatment. CSF was regularly sampled from an intraventricular reservoir and collected in CEE-sure™ collection tubes. Biocept, Inc.’s CNSide™ platform was used to capture cells which then underwent immunocytochemistry as well as fluorescent in-situ hybridization (FISH) analysis, identifying biomarkers.

CSF tumor cells were routinely identified in these samples, with values ranging broadly depending on disease severity and burden.  We were able to track treatment response as the CSF tumor cell load appeared to decrease after treatment and correlated to clinical improvement. CNSide was also helpful in identifying key biomarkers such as HER2, EGFR, C-MYC, which in turn have therapeutic implications. 

CSF analysis with tumor cell isolation platforms such as CNSide, developed by Biocept Inc., holds significant promise as a safe and minimally invasive means of identifying LMD, monitoring disease burden and assessing for the treatment response of the LMD tumor.