The Gap in Treatment Monitoring
For patients undergoing cancer treatment, one of the most critical and underserved clinical questions is simple but profound: Is this therapy working?
Traditional imaging lacks the spatial and temporal resolution to detect early shifts in tumour burden:- meaning oncologists often wait weeks or months before knowing whether a treatment is effective, ineffective, or causing resistance.
At 1Cell.ai, we developed OncoAlibrex : a highly sensitive, NGS-independent cfDNA fragmentomics assay designed to answer that question earlier, faster, and with far greater precision than conventional monitoring methods.
The Science of Fragmentomics
OncoAlibrex is built on a powerful biological insight: cancer cells release cfDNA fragments into the bloodstream in patterns that are distinctly different from those released by healthy cells. By characterising the fragmentation patterns of cell-free DNA, rather than simply detecting mutations: OncoAlibrex can detect tumour-specific signals even at extremely low tumour fractions, making it a powerful tool for Therapy Response Monitoring (TRM) and Minimal Residual Disease (MRD) detection.
Our assay evaluates cfDNA fragment distributions at three key size ranges — >80 bp, >105 bp, and >265 bp, using fragment-specific primer pairs designed based on high copy number Alu and SVA retrotransposons across the genome. Therapy response is then predicted using an integrated algorithm that interprets cfDNA fragment distribution in real time.
Analytical Validation Results
OncoAlibrex was analytically validated using cfDNA extracted from healthy plasma and cancer patient samples (n=140), analysed in triplicate across multiple days, operators, and reagent lots. The results demonstrated exceptional analytical performance:
- Intra-assay variability ≤1% for ct value and ≤13% for ratiometric quantity
- Inter-assay precision <2.0% ct variability
- Excellent linearity (R² ≥ 0.99) across 0.6 pg to 20 ng/µL of ccfDNA
- qPCR efficiencies >98% across all tested concentrations
- 100% specificity: the cfDNA fragmentation pattern of cancer patients showed high progression scores, reliably distinguishing therapy non-response from healthy controls
- Fragmentation patterns of patient-derived ccfDNA were enriched with shorter fragments (80-105 bp) compared to healthy individuals:- a robust and reproducible tumour-specific signature
Why This Matters
OncoAlibrex addresses a critical unmet need in oncology: the ability to assess treatment response early, accurately, and non-invasively, without relying on sequencing-based methods that may miss signals at very low tumour fractions.
By detecting tumour-specific cfDNA fragmentation patterns with very high sensitivity, specificity, and accuracy, OncoAlibrex can be used for TRM during the early phases of treatment and for MRD detection post-treatment, giving oncologists the information they need to make faster, better-informed decisions for their patients.
This is 1Cell.ai’s vision of liquid biopsy taken to its next frontier.
Presented at the AACR Annual Meeting 2026, San Diego, CA | April 17–22, 2026 | #AACR26
Presented by Atul Bharde et al | April 19, 2026 | Session PO.CL01.02