Resero Bio Advances RNA Liquid Biopsy for Bladder Cancer

San Carlos, California, U.S., October 5, 2026

Resero Bio Platform Detects Bladder Cancer From Urine

The study, conducted by researchers from Stanford Cancer Institute, the VA Palo Alto Health Care System and collaborating institutions, investigated whether RNA fragments circulating in urine could provide information beyond simply determining whether cancer is present. Using the uRARE-seq approach, the researchers evaluated molecular signals in urine samples and found that cfRNA could support sensitive bladder cancer detection while also distinguishing between low-grade and high-grade tumors and between non-muscle-invasive and muscle-invasive disease. These classifications are clinically important because tumor grade and stage influence treatment decisions and disease management. The findings point toward a potential role for liquid biopsy approaches in situations where conventional assessment may require tissue obtained through biopsy or surgical resection. Rather than analyzing only the presence of tumor-associated material, the platform examines gene-expression information contained within cell-free RNA, potentially providing a broader molecular view of disease. Resero Bio said the findings represent an important expansion of its RARE-seq platform from cancer detection toward deeper characterization of tumor biology.

cfRNA Shows Treatment Response and Residual Disease

One of the most significant findings was the ability of the platform to identify a pre-treatment molecular signature associated with response to BCG immunotherapy. Patients who achieved a complete molecular response to BCG showed pre-existing anti-tumor immune-response signatures in urine cfRNA before treatment began. This suggests that molecular information obtained before therapy could potentially help researchers identify biological characteristics associated with treatment response. The study also demonstrated the ability to identify molecular residual disease after treatment. Urine cfRNA profiles distinguished patients who achieved complete molecular responses following surgery from those with incomplete responses. Patients with complete molecular responses to surgery or BCG had substantially lower recurrence risk than patients with detectable tumor-derived cfRNA after treatment, according to the study findings. These observations highlight the potential value of molecular monitoring for assessing whether cancer-associated signals remain after treatment. For bladder cancer management, the ability to obtain molecular information repeatedly from a non-invasive urine sample could be particularly relevant. Clinicians currently make important decisions about tumor aggressiveness, treatment selection and residual disease using a combination of pathology, imaging, cystoscopy and other clinical assessments. A liquid biopsy capable of providing complementary molecular information could potentially add another layer of information to these decisions.

Resero Bio Expands RARE-seq Precision Diagnostics

The findings also support broader development of Resero Bio’s RARE-seq platform, which is designed to analyze cell-free RNA from urine and plasma. The company says the technology combines targeted cfRNA sequencing with an AI/ML-enabled bioinformatics engine to generate information related to cancer detection, molecular and histological subtyping, risk stratification, treatment response and pharmacodynamic monitoring. The Nature Medicine study also provided preliminary evidence that urine cfRNA may contain distinct transcriptional profiles associated with renal cell carcinoma and prostate adenocarcinoma, suggesting potential applications beyond bladder cancer. Resero Bio reported that proof-of-concept cfRNA signals have been generated across 10 solid tumor types, although further research will be required to establish the clinical utility and performance of the platform in each cancer type.

The publication represents an important milestone for precision oncology and liquid biopsy research, particularly because it demonstrates how cfRNA may provide information about both cancer presence and underlying tumor biology. For Resero Bio, the results strengthen the scientific foundation of its RARE-seq technology and its goal of developing non-invasive molecular diagnostics that can support cancer detection, treatment selection and monitoring. Further clinical validation will be important before such applications can become part of routine patient care.

Source: Resero Bio press release