Bio-Rad Laboratories Industry Symposium: Bio-Rad Laboratories sponsored Industry Symposium: Tumour Informed ctDNA Analysis by Droplet Digital PCR for Treatment Monitoring in Metastatic Cancer

Ultrasensitive methods of detection for low frequency variants are necessary in fields like Oncology to improve patient diagnosis and treatment. Bio-Rad developed a highly sensitive technology, the Droplet Digital PCR (ddPCR), for plasma and tumour tissue biopsy. It identifies prevalent mutations in relevant genes like Estrogen Receptor 1 (ESR1), detected at variant allele frequency (VAF) below 1% in approximately 40% of breast cancer patients. Owing to its sensitivity and short around time, ddPCR emerged as an extremely valuable tool for disease monitoring that facilitates the access to personalized treatments such as Elacestrant or Camizestrant for metastatic breast cancer patients

Chemo-immunotherapy has become the standard first-line treatment for metastatic non-small cell lung cancer (NSCLC); however, reliable biomarkers to guide patient selection and predict treatment response are still lacking. In the B-IO Study, we aim to predict response to chemo-immunotherapy in 73 stage IV NSCLC patients with known driver mutations who progressed after tyrosine kinase inhibitor treatment. We focus on personalized monitoring of therapy response to chemo-immunotherapy using ddPCR-based ctDNA analysis. Serial plasma samples were collected during treatment and analysed by plasma-based next-generation sequencing and patient-specific digital droplet PCR. At baseline, both tumour- (Roche AVENIO CGP) and ctDNA profiling with Roche AVENIO ctDNA Expanded and Surveillance v2 NGS panels were performed to identify tumor-specific mutations, which were then used to design patient- specific Bio-Rad ddPCR assays. Experience with multicolor-ddPCR analysis using tumour- and/or plasma-baseline selected mutations will be presented.