Aqtual's Blood Test Decodes Immune and Tumor Talk in Sarcoma

CHICAGO, IL – June 01, 2026 – In a significant leap for precision oncology, a single blood test has demonstrated the ability to simultaneously listen in on the complex biological conversations between a tumor, the patient's immune system, and the surrounding tissue. New findings from precision medicine company Aqtual, Inc., presented today at the American Society of Clinical Oncology (ASCO) Annual Meeting, reveal a liquid biopsy platform that offers a panoramic view of cancer biology, a feat that could revolutionize how doctors monitor and treat notoriously difficult cancers like sarcoma.

The technology, which profiles active chromatin in cell-free DNA (cfDNA), moves beyond the traditional search for tumor mutations. Instead, it provides a functional, real-time snapshot of the gene activity driving a cancer's growth, its interaction with the body, and its potential to resist treatment. For patients with leiomyosarcoma, a rare and aggressive cancer, this multi-signal approach offers a non-invasive tool to predict immunotherapy response where options have historically been limited.

Beyond a Genetic Blueprint

For years, the liquid biopsy field has been dominated by technologies that hunt for fragments of circulating tumor DNA (ctDNA) to identify specific genetic mutations. While transformative, this approach has limitations, particularly in cancers with a low tumor mutation burden (TMB), such as many sarcomas. In these cases, the ctDNA signal can be too faint to detect reliably, leaving clinicians and patients without a clear, non-invasive way to track the disease.

Aqtual's platform circumvents this challenge by changing the question. Rather than asking what genetic mutations the tumor has, it asks what genes are currently active across the entire tumor microenvironment. By enriching for cfDNA fragments associated with active chromatin—the regions of the genome that are unwound and being actively transcribed—the test creates a profile of the body's real-time transcriptional landscape. This provides a proxy for gene expression not just in the tumor, but also in the immune cells fighting it and the stromal cells that form its structural support system.

“The significance of this work is not any single biomarker, but the architecture behind them,” said Diana Abdueva, PhD, Co-Founder and Chief Executive Officer of Aqtual, in a statement. “Existing liquid biopsy platforms typically read tumor mutations, tissue origin, or fragmentation patterns independently. In a single library, our platform reads immune state, stromal state, and tumor genomics simultaneously.”

This integrated analysis is the core of the breakthrough. It captures the dynamic interplay of forces that determine whether a treatment will succeed or fail, providing a far richer dataset from a single blood draw than previously possible.

Decoding Sarcoma's Response to Immunotherapy

The clinical potential of this approach was detailed in a recent study published in the peer-reviewed journal npj Precision Oncology. Investigators at UHN’s Princess Margaret Cancer Centre in Toronto analyzed blood samples from a cohort of 30 patients with advanced leiomyosarcoma who were being treated with a durvalumab-based immunotherapy combination.

The results were striking. The platform successfully identified distinct biological signatures in pre-treatment blood samples that correlated with patient outcomes. These signatures fell into three critical categories:

• Immune Activation: Patients whose blood showed strong signatures of B-cell and T-cell activation—indicating a mobilized immune system ready to fight—had significantly longer progression-free survival (HR 4.07 and HR 4.27, respectively).

• Stromal Resistance: Conversely, signatures associated with stromal remodeling and extracellular matrix organization, which can create a physical barrier protecting the tumor, were linked to treatment resistance and shorter progression-free survival (HR 0.17).

• Tumor Genomics: The platform also captured traditional genomic features. A higher tumor fraction (above 5%) and specific copy number variations were also correlated with poorer outcomes (HR 3.33).

Crucially, the study validated that these blood-based signals were not just noise; they were a true reflection of the biology within the tumor itself. The plasma-derived promoter activity showed a strong correlation of 0.81 with matched tumor RNA sequencing, confirming that the test accurately mirrors the transcriptional programs happening at the disease site. This is a vital proof point, especially in a disease where obtaining repeat tissue biopsies is often difficult or infeasible.

“There is an important need for predictive biomarkers that may help identify which patients with leiomyosarcoma are most likely to benefit from immunotherapy approaches,” noted Dr. Albiruni Abdul Razak, a Clinician Investigator at UHN’s Princess Margaret Cancer Centre and a lead author on the study. “This study provides preliminary evidence that a simple blood test taken before treatment may help identify which patients could benefit from combination immunotherapy approaches.”

Mapping the Emergence of Resistance

The latest data presented at ASCO takes this a step further, moving from a static, pre-treatment snapshot to a dynamic view of how cancer evolves under the pressure of therapy. By analyzing paired blood samples taken at baseline and again when a patient's cancer progressed, the researchers were able to track how the immune, stromal, and tumor signals changed over time.

This longitudinal analysis offers an early and powerful glimpse into the mechanisms of acquired resistance. It helps answer one of the most pressing questions in modern oncology: why do some patients who initially respond to powerful immunotherapies eventually see their cancer return and grow? By watching these biological signals shift, clinicians could one day anticipate resistance before it becomes clinically apparent, allowing them to adapt treatment strategies proactively.

This capability is particularly valuable in the challenging setting of leiomyosarcoma, where immunotherapy has shown limited success and understanding resistance is key to improving outcomes. The ability to non-invasively monitor these complex dynamics provides a critical tool for both clinical practice and future drug development.

While Aqtual is carving out a distinct niche in difficult-to-treat cancers, the platform's technology is also being validated in other areas, including a 1,000-patient study for predicting treatment response in rheumatoid arthritis. This broader application underscores the robustness of using active chromatin analysis to decode disease biology.

As acknowledged by the company, these initial oncology findings were generated in a small patient cohort and now require confirmation in larger, independent studies, which are reportedly underway. Nonetheless, the work represents a conceptual shift in the liquid biopsy landscape, moving the field toward a more holistic and functional understanding of cancer that could one day make personalized medicine a reality for even more patients.