Tumor progression in late-stage melanoma patients is typically monitored with imaging techniques such as PET-CT, which is sometimes accompanied by unspecific and non-sensitive assessment of blood biomarkers. While several molecular assays to detect and quantify circulating cell-free DNA (ccfDNA) derived from tumor cells have been developed, the classification of patient samples is subjective and difficult to standardize.
Oncobit AG has developed a novel digital PCR assay that is accompanied by a tailored software solution to analyze and interpret digital PCR data. ccfDNA isolated from melanoma patient samples is subjected to targeted amplification in up to 20’000 droplets, using Bio-Rads ddPCR™ technology. The amplified target sequences are detected by hybridization to fluorescent-conjugated oligonucleotides that are specific for the BRAF wildtype or the BRAF V600 mutant nucleotide sequence. Their customized digital PCR analysis algorithm allows a robust and systematic classification of droplets and thus patient samples and yields an absolute quantification of cancer molecules.
Oncobit AG has investigated 200 plasma samples from 150 patients with melanoma of AJCC stages III and IV for the presence of BRAF V600 mutant molecules via digital PCR. Comparing the results to routine monitoring techniques, they confirmed that digital PCR can be used as a sensitive tool to the monitor the progression of metastatic melanoma patients.
The introduction of a tailored digital PCR analysis algorithm allowed Oncobit AG to develop a robust yet sensitive digital PCR assay that can be used for the monitoring of treatment response, cancer recurrence, and minimum residual disease.
Dr. sc. nat. Elisa Bellini,
Senior Scientist, Oncobit AG, Rütistrasse 16, CH-8952 Schlieren
Elisa Bellini has a PhD in Molecular and Translational Biomedicine from the University of Zurich and a Certificate of Advanced Studies in Clinical Trial Management from the University of Basel. Elisa Bellini has more than 7 years of experience in the fields of precision medicine and cancer diagnostics, including 4 years at the specialized laboratory of diagnostic molecular pathology of the University Hospital of Zurich. After 3 years as research associate in the group of Prof. Levesque, Elisa Bellini joined Oncobit as Senior Scientist.