FDA Approves Guardant360 CDx as Companion Diagnostic for Osimertinib

The FDA has approved the Guardant360 CDx assay as a companion diagnostic for the identification of patients with non–small cell lung cancer (NSCLC) harboring EGFR alterations who may benefit from treatment with osimertinib (Tagrisso). According to the FDA, this is the first liquid biopsy companion diagnostic to use next-generation sequencing (NGS) technology to guide treatment decisions.^1,2

“Approval of a companion diagnostic that uses a liquid biopsy and leverages next-generation sequencing marks a new era for mutation testing,” said Tim Stenzel, MD, PhD, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health, in a statement. “In addition to benefitting from less invasive testing, patients are provided with a simultaneous mapping of multiple biomarkers of genomic alterations, rather than one biomarker at a time, which can translate to decreased wait times for starting treatment and provide insight into possible resistance mechanisms.”

The use of the assay offers oncologists the ability to obtain critical genomic information on their patients with a simple, quick blood draw that may lead to more personalized treatment approaches. The test is also broadly covered by Medicare and many private payers.

“The FDA approval of Guardant360 CDx is a landmark decision, demonstrating the value liquid biopsy delivers to oncologists and more importantly, the patients they treat. Traditional tissue biopsy-based tumor profiling, which is often invasive and has longer turnaround times, can contribute to delays in starting treatment and possibly suboptimal therapy,” said Helmy Eltoukhy, CEO of Guardant Health, in a press release. “We are confident that our FDA approval will help accelerate wider adoption of guideline-recommended genomic profiling, increase the number of [patients with] advanced cancer who receive potentially life-changing treatments, and pave the way for new companion diagnostic developments for the Guardant360 CDx.”

Approval for the assay was based on clinical and analytical validation data from over 5000 patient samples.

Retrospective analyses of data from the pivotal phase 3 FLAURA and AURA3 clinical trials of osimertinib in patients with EGFR-mutant NSCLC demonstrated that the use of the liquid biopsy showed consistent progression-free survival rates with rates seen using traditional biomarker testing.

“Personalized medicines such as Tagrisso have been truly life-changing for many [patients with] non–small cell lung cancer who have certain EGFR mutations and are most likely to benefit from this medicine,” Jhanelle Gray, MD, senior member and chair, Department of Thoracic Oncology, and co-leader, Chemical Biology & Molecular Medicine Program, Moffitt Cancer Center, said in a press release. “It is crucial that all patients are comprehensively tested before starting treatment to ensure they receive the most appropriate personalized treatment option available.”

The assay previously received a Breakthrough Device designation from the FDA as well.

_References

_{1. Guardant Health Guardant360® CDx First FDA-Approved Liquid Biopsy for Comprehensive Tumor Mutation Profiling Across All Solid Cancers. News release. Guardant Health. August 7, 2020. Accessed August 10, 2020. https://bit.ly/3aclIdI}

_{2. FDA Approves First Liquid Biopsy Next-Generation Sequencing Companion Diagnostic Test. News release. FDA. August 7, 2020. Accessed August 10, 2020. https://bit.ly/3krsaTb}