NEW YORK (GenomeWeb) – Bio-Rad Laboratories has received clearance from the US Food and Drug Administration for its first liquid biopsy assay and Droplet Digital PCR system for diagnostic use, the firm announced today.
The test is designed for monitoring treatment response in chronic myeloid leukemia and is also the first-ever digital PCR product to receive FDA clearance, according to the company.
The test, called the QXDx BCR-ABL %IS Kit, was CE marked in late 2017. It quantifies BCR-ABL fusions, specifically p210 transcripts, and can detect the residual levels seen in patients on tyrosine kinase inhibitor therapy. Measuring residual levels of BCR-ABL in CML patients treated with the first-line TKI imatinib, for example, can help physicians decide whether it might be necessary to start a second-line TKI, such as dasatinib, nilotinib, or bosutinib.
The test uses Bio-Rad's clinical instrument, called the QXDx AutoDG ddPCR System. It is designed to give users the flexibility to run FDA-cleared IVD tests as well as lab-developed tests and uses a simple, user-friendly workflow that is also scalable.
Digital PCR-based methods can offer lower levels of resolution than standard RT-qPCR. Bio-Rad's new test can detect molecular response down to MR 4.7 (LOD), or 0.002 percent on an International Scale, according to the firm's website, with levels of BCR-ABL between 0.01 and 0.001 percent defining a so-called deep molecular response that predicts better long-term outcomes.
Bio-Rad introduced ddPCR as a research tool in 2012, and it was quickly adopted for liquid biopsy and rare mutation detection in cancer research, the firm noted in a statement. To date, there are more than 3,400 publications citing the ddPCR technology, including more than 900 publications focused on liquid biopsy, Bio-Rad said.
The firm has previously disclosed that it intends to continue to develop assays within the liquid biopsy space — especially for residual disease monitoring — as well as tests for other applications, both internally and in partnership with other kit developers.