SAGA Diagnostics to Present New Pathlight™ MRD Data for Ovarian and Metastatic Breast Cancer at AACR 2026
Ultrasensitive, structural variant-based ctDNA monitoring reliably tracks therapeutic response and predicts progression in metastatic breast cancer, and is a strong independent prognostic marker in advanced ovarian cancers
MORRISVILLE, NC — April 17, 2026 — SAGA Diagnostics, a pioneer in blood-based cancer detection and precision medicine redefining the standard for early molecular residual disease (MRD) detection, today announced that the company and its collaborators will present data from two abstracts at the 2026 American Association for Cancer Research (AACR) Annual Meeting, taking place April 17–22 in San Diego, California. These abstracts showcase the ultrasensitive structural variant (SV)-based detection of circulating tumor DNA (ctDNA) in metastatic breast cancer (mBC) and high-grade serous ovarian cancer (HGSOC).
SV-based ctDNA Monitoring in Metastatic Breast Cancer (mBC)
In collaboration with Drs. David Cescon and Mitchell Elliott at University Health Network (UHN) Canada, a retrospective analysis was conducted for patients with mBC (all subtypes) undergoing standard systemic therapy, utilizing the Pathlight SV-based MRD test. SAGA was able to successfully generate fingerprints in 66 patients using standard tissue-based Pathlight. Using ultradeep cfDNA-based whole-genome sequencing, SV-based tissue-free fingerprints were generated to rescue additional patients for which tissue was unavailable, enabling these patients to benefit from informed MRD testing.
The study’s SV-based approach achieved a high 77% detection rate (294/380) for ctDNA, with nearly a third of those cases identified in the ultrasensitive range. Additionally, Pathlight proved to be a powerful predictor of patient outcomes: where ctDNA was undetectable, patients showed exceptional responses to therapy, including prolonged disease stability and complete clinical response. Furthermore, Pathlight successfully tracked treatment responses across multiple lines of therapy, with rising ctDNA levels preceding radiologic signs of disease progression.
“Metastatic breast cancer remains a challenge to manage clinically, and the use of an accurate complementary biomarker may help improve the care for our patients,” said Mitchell Elliott, MD, FRCPC. “By leveraging structural variants – highly conserved features of the tumor genome – we enable ultrasensitive ctDNA detection in the metastatic setting which closely aligns with standard of care radiographic assessment. This approach supports the potential for more reliable treatment monitoring and unlocks new opportunities for clinical utility in this setting”.
Improved Prognostic Assessment in Ovarian Cancer
In collaboration with the Medical University of Vienna and LMU Munich, a retrospective analysis was performed on plasma samples collected prospectively from 84 patients with advanced high-grade serous ovarian cancer (HGSOC). High baseline detection was observed (94%), with MRD remaining in 85% of cases postoperatively. Within the subgroup of patients with pathological complete tumor resection, ctDNA clearance at the first cycle of chemotherapy (C1) (20%) and the sixth cycle (C6) (70%) was associated with significantly lower recurrence risk compared to those with persistent ctDNA. Most notably, ctDNA persistence at C6 was identified as a powerful independent prognostic marker, where ctDNA-positive patients faced a median time to clinical recurrence of just 10.7 months compared to 21.3 months for those who cleared ctDNA. While CA-125 levels failed to significantly predict recurrence at key treatment milestones, ctDNA dynamics offered precise risk stratification even after optimal primary surgery, providing a vital clinical window for personalized maintenance strategies and risk-adjusted treatment interventions.
“The consistent performance of SV-based MRD monitoring by Pathlight across these diverse, late-stage cancers underscores its broad clinical applicability,” added Wendy Levin, MD, MS, Chief Clinical Officer of Saga Diagnostics. “This isn’t just about better data, it’s about the potential for clinical utility. By accurately informing on treatment monitoring where traditional tools fail, we are unlocking the ability to tailor therapies in real-time, ultimately improving outcomes through more informed, individualized patient management.”
Key SAGA Diagnostics Presentations During AACR 2026:
| Abstract Title | Presentation Details |
|---|---|
| Tumor-informed circulating tumor DNA identifies high-grade serous ovarian cancer patients at highest risk for recurrence despite optimal first-line treatment with primary macroscopic complete resection | Poster Presentation Location: Section 42 Date: April 19, 2026 Time: 2:00-5:00 PM Speaker: Magdalena Postl, MD |
| Serial ctDNA monitoring in metastatic breast cancer using an ultrasensitive tumor-informed structural variant-based assay | Poster Presentation: #3864 Location: Section 45 Date: April 20, 2026 Time: 2:00-5:00 PM Speaker: Mitchell Elliott, MD, FRCPC |
The full abstracts for SAGA Diagnostics at AACR 2026 can be found here.
Find Out MoreAbout SAGA Diagnostics
SAGA Diagnostics® is redefining the early detection of molecular residual disease (MRD), empowering treatment decisions with greater insight and confidence. Pathlight™, the company’s flagship product, is an ultra-sensitive, blood-based, multi-cancer MRD test that is now available for commercial use in the U.S and reimbursed for patients with early stage breast cancer. SAGA is partnering with pharmaceutical and biotechnology companies, as well as commercial entities, to support early through late-stage cancer development programs across a range of cancer types. SAGA’s headquarters and CLIA-certified laboratory are located in the heart of the life science ecosystem in Research Triangle Park, North Carolina. SAGA Diagnostics combines world-class genomic expertise with a leadership team deeply experienced in MRD, all aligned in the mission to intercept cancer at its earliest stages when it is most treatable. For more information, visit sagadiagnostics.com.
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