Summary:
SAGA Diagnostics has launched Pathlight, a groundbreaking multi-cancer blood test for ultra-sensitive detection of molecular residual disease (MRD), debuting at ASCO 2025 with clinical validation in early breast cancer.

Takeaways:

  1. First-of-its-kind MRD platform: Pathlight uses structural variants (SVs) as personalized tumor biomarkers, enabling precise and early detection of recurrence.
  2. Clinically validated performance: In the TRACER study, Pathlight showed 100% sensitivity and specificity, with a 13.7-month lead time to recurrence in breast cancer patients.
  3. Broad application and adoption: Pathlight is analytically validated across multiple cancer types, used in clinical studies, and submitted for reimbursement via the MolDX Program.

SAGA Diagnostics, a pioneer in blood-based cancer detection and precision medicine redefining the standard for ultra-sensitive and early molecular residual disease (MRD) detection, today announced the U.S. commercial launch of its Pathlight test for the detection of residual disease and recurrence at the 2025 American Society for Clinical Oncology (ASCO) Annual Meeting in Chicago.

Pathlight Is First-of-Its-Kind MRD Platform

Pathlight is a first-of-its-kind, multi-cancer MRD platform, initially indicated for early breast cancer, that uses structural variants (SVs) as biomarkers. SVs are well-established hallmarks of cancer, arising from and contributing to genomic instability and oncogenesis. SVs, including breakpoints and rearrangements, are highly underlying tumor biology tumor- and patient-specific and often reflect the making them informative biomarkers for tracking disease.

Pathlight combines whole genome sequencing and proprietary algorithms and informatics optimized for the identification of stable SV breakpoints, generating a personalized genomic fingerprint for each tumor, which are subsequently orthogonally validated and tracked utilizing proprietary multiplex digital PCR to enable rapid, precise, efficient and quantitative MRD detection from a simple blood draw.

“By tracking structural variants—stable, unique, and tumor-defining fingerprints of each patient’s cancer—Pathlight enables interception of recurrence at its most treatable and potentially curable stage,” says Roopom Banerjee, executive chairman of SAGA Diagnostics. “Our goal is to deliver the most accurate, trusted results that provide assurance and support confident, informed treatment decisions. Our published, peer reviewed data demonstrates the clinical validity of Pathlight in breast cancer and its potential power across all solid tumors and heme malignancies. SAGA has further partnered with leading clinicians, institutions, and biopharma to bring Pathlight to market and best serve patients.”

Establishing Clinical Validity

The clinical validity of Pathlight was established with samples collected in the TRACER (cTdna evaluation in eaRly breAst canCER) study, published in Clinical Cancer Research1 in January 2025. In this retrospective analysis of 100 patients with stage I–III breast cancer of all subtypes receiving standard-of-care neoadjuvant and adjuvant therapy Pathlight demonstrated best-in-class clinical performance – with 100% sensitivity and 100% specificity, and a 13.7-month lead time to recurrence as confirmed by clinical presentation or imaging. Notably, Pathlight’s baseline detection rate was 96% overall, and 94% in estrogen receptor-positive (ER+) breast cancer, which suggests clinical advantages over first generation ctDNA assays. Pathlight also delivered unparalleled sensitivity – breaking the 1ppm barrier and offers the potential to detect MRD at the earliest possible opportunity, to support individualized intervention directed towards cure.

“The vast majority of breast cancer patients are diagnosed with ER+ disease, and up to 25% will experience recurrence – often many years after completing curative-intent treatment,” says David Cescon, MD, PhD, medical oncologist and clinician scientist at Princess Margaret Cancer Centre, University Health Network and senior author of the paper. “We know that continued improvement in outcomes for people diagnosed with early breast cancer will require a shift towards more individualized treatment. There is a critical need for MRD testing that is both ultra-sensitive and ultra-specific, to enable long-term surveillance and risk-aligned treatment decisions for each patient.”

Pathlight has been submitted for US Reimbursement via the MolDX Program and is analytically validated across multiple cancer types. The test is already being used successfully in clinical studies by top pharmaceutical companies and at preeminent academic institutions and national cancer centers.

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Reference

1. Elliott MJ, Howarth K, Main S, et al. Ultrasensitive detection and monitoring of circulating tumor DNA using structural variants in early-stage breast cancer. Clin Cancer Res. 2025;31(8):1520-1532. doi:10.1158/1078-0432.CCR-24-3472