FDA approved the therascreen PDGFRA RGQ PCR kit, a companion diagnostic intended for use to aid clinicians in identifying patients with gastrointestinal stromal tumors who may be eligible for treatment with Ayvakit (avapritinib).
Ayvakit is approved in the U.S. for the treatment of adults with unresectable or metastatic GIST harboring a platelet-derived growth factor receptor alpha exon 18 mutation, including PDGFRA D842V mutations.
The kit is the first platelet-derived growth factor receptor alpha assay to receive FDA approval as a companion diagnostic.
Qiagen and Blueprint Medicines collaboratively developed the PDGFRA companion diagnostic assay. The real-time qualitative PCR in vitro diagnostic assay detects the D842V somatic mutation in the PDGFRA gene to determine which patients may be a candidate for treatment with Ayvakit.
The tyrosine kinase inhibitor is designed to target the PDGFRA exon 18 D842V mutation and was approved by the FDA in 2020. GIST patients harboring the D842V mutation in PDGFRA exon 18 show primary resistance to previously approved TKIs.
The therascreen PDGFRA kit uses genomic DNA extracted from a patient’s formalin-fixed paraffin-embedded tumor tissue. FFPE tumor specimens are processed using the QIAamp DSP DNA FFPE Tissue Kit for sample preparation and the Rotor-Gene Q MDx instrument for DNA amplification and mutation detection.
“The therascreen PDGFRA kit is an FDA approved and validated test, delivering results in a fast turnaround time. This ensures that physicians receive results promptly, enabling them to make informed treatment decisions for their GIST patients in a timely and effective manner,” Jonathan Arnold, vice president and head of translational science and precision diagnostics at Qiagen, said in a statement.
GIST is a rare, genomically driven sarcoma of the gastrointestinal tract. Approximately six% of patients with newly diagnosed GIST have PDGFRA exon 18 mutations, the most common of which is the D842V mutation. Since the introduction of TKIs, including Ayvakit, the treatment of GIST patients with locally advanced and metastatic disease has dramatically improved.
