SAGA Diagnostics to Present New Pathlight™ MRD Data for Ovarian and Metastatic Breast Cancer at AACR 2026

Key Takeaways

• 77% ctDNA detection in metastatic breast cancer, one‑third ultrasensitive
• 94% baseline ctDNA detection in advanced ovarian cancer
• ctDNA clearance at cycle 6 halves recurrence risk versus persistence
• Pathlight outperforms CA‑125 for recurrence prediction after surgery

Pulse Analysis

SAGA Diagnostics is leveraging its Pathlight™ platform to push the boundaries of molecular residual disease (MRD) testing. By focusing on structural variants—stable genomic alterations unique to each tumor—the company’s ultrasensitive ctDNA assay can detect trace amounts of tumor DNA in blood, a capability that proved critical in two retrospective studies presented at AACR 2026. In metastatic breast cancer, the assay identified circulating tumor DNA in 77% of patients, with one‑third of detections falling into an ultrasensitive range that anticipated radiologic progression, offering clinicians a potential early warning system for treatment failure.

The ovarian cancer data reinforce Pathlight’s prognostic strength. Among 84 patients with high‑grade serous ovarian cancer, baseline ctDNA was found in 94% of cases, and persistence of ctDNA after six cycles of chemotherapy predicted a median time to recurrence of just 10.7 months—half the duration observed in patients who cleared the marker. Notably, traditional CA‑125 levels failed to stratify risk at these key milestones, underscoring the assay’s superior predictive power and its role in guiding maintenance therapy decisions.

For the broader oncology ecosystem, these results signal a shift toward blood‑based, tumor‑informed monitoring that can complement or even supplant imaging in certain scenarios. Pharma companies developing targeted agents stand to benefit from more precise patient selection and real‑time efficacy readouts, while clinicians gain a tool to tailor interventions swiftly. As Pathlight gains commercial traction in the U.S., its adoption could accelerate across multiple tumor types, reshaping standards for MRD assessment and reinforcing SAGA’s position as a leader in precision oncology diagnostics.