# Therapeutic Focus: Oncology ## From blood to breakthroughs: how multi-analyte liquid biopsies can transform precision oncology, drug development and clinical trials ### Addressing key oncology drug development challenges through multi-analyte liquid biopsy approaches **Karen Miller** and **Sydney Barrell** at **ANGLE plc** Multi-analyte and multi-omic **liquid biopsy** is a minimally invasive procedure that analyses multiple tumour-derived components (**analytes**) in body fluids (generally blood) to provide a real-time, comprehensive view of a patient's cancer. Such **multi-omic analysis** is transforming oncology drug development by addressing key challenges that pharmaceutical companies face in early drug development and clinical trials. Multi-analyte liquid biopsy analysis provides a cost-effective means to stratify patient cohorts, track clonal evolution and tumour heterogeneity, detect resistance mutations early, and identify **minimal residual disease (MRD)**. As such, liquid biopsy provides real-time insights that can enhance clinical trial outcomes. The complexity of cancer biology presents significant challenges for the pharmaceutical industry, particularly in developing effective, targeted treatments. While valuable for initial diagnostics, traditional tissue biopsies are invasive and impractical for repeat monitoring of patients. Liquid biopsy offers a transformative, minimally invasive solution for analysing multiple biomarkers circulating in the bloodstream. By incorporating multi-analyte and multi-omic data, liquid biopsy can address some of the key challenges in oncology drug development and clinical trials, from patient stratification and monitoring tumour dynamics to enhancing patient safety and trial efficiency. \[Image placeholder: Figure 1: Use of liquid biopsy in the patient care pathway.\] ------------------------------------------------------------------------ ## The multi-analyte approach Liquid biopsy analytes, primarily **circulating tumour DNA (ctDNA)** and **circulating tumour cells (CTCs)**, provide complementary insights into the tumour landscape. ### ctDNA **ctDNA** -- the most established analyte in liquid biopsy due to straightforward sample collection, molecular analysis and significant investment -- consists of fragmented DNA released predominantly from dying cancer cells through necrosis or apoptosis. Through analysis of **ctDNA**, researchers can identify mutation status and track genetic changes associated with resistance or disease progression. ### CTCs This information can also be obtained by analysing genomic DNA (**gDNA**) derived from **CTCs** -- intact, viable tumour cells that spread the cancer, often referred to as the 'seeds of metastasis'. CTCs are the closest proxy to solid tissue biopsy. They not only carry **gDNA** but also a wealth of information in their **proteome**, **transcriptome** and **metabolome** (**multi-omic data**). By analysing proteins, RNA and metabolites within CTCs and CTC clusters, researchers can gain additional insights into tumour aggressiveness, metastatic potential and altered metabolic pathways. ### Additional analytes Other liquid biopsy analytes include: - **Exosomes (extracellular vesicles \[EVs\])** - **Circulating free RNA (cfRNA)** - Specific **proteins** - **Metabolites** These potentially offer additional clues about immune evasion and intercellular signalling. The dual analysis of **ctDNA** and **CTCs** is gaining traction and provides valuable complementary insights into tumour dynamics, enabling real-time, adaptive responses to cancer's complex behaviours. ------------------------------------------------------------------------ ## Some key challenges faced in oncology drug development and clinical trials ### Challenge: need for real-time monitoring Traditional biopsies are invasive, costly and unsuitable for repeat sampling, and may only be repeated once more from a metastatic site. The unsuitability of tissue for real-time monitoring to detect changes in tumour dynamics prevents timely and effective treatment decisions. Multi-analyte liquid biopsy provides an ideal solution by enabling repeat sampling to provide a real-time view of tumour evolution. Through regular analysis of **ctDNA**, **CTCs** and other analytes, researchers gain continuous insights into tumour progression, mutation patterns and cell behaviour, capturing changes that could otherwise go unnoticed. One study found that **HER2 status changed in 37% of breast cancer recurrences**, underscoring the importance of re-evaluating tumour biomarkers to optimise drug treatment. Multiple papers describe how liquid biopsy is effective in detecting **minimal residual disease (MRD)**, often providing early indication of relapse before traditional imaging methods reveal progression. In one case, **CTC enumeration indicated the presence of MRD four years before clinically detectable metastatic disease**, offering early insights for therapeutic management. In clinical trials, real-time molecular data from liquid biopsies could prove invaluable by: 1. Monitoring treatment efficacy more rapidly\ 2. Evaluating biomarker changes over time\ 3. Making data-driven adjustments to trial strategies ------------------------------------------------------------------------ ### Challenge: tumour heterogeneity and drug resistance monitoring Cancer's inherent variability presents a major obstacle in oncology, as both **interpatient heterogeneity** and **intrapatient heterogeneity** make treatment selection and efficacy difficult to predict. Tumours evolve dynamically, with cancer cell populations mutating in response to therapies, often leading to treatment resistance. Multi-analyte liquid biopsy tackles tumour heterogeneity and drug resistance by providing a comprehensive, real-time molecular profile that captures a tumour's evolution. By integrating data from **ctDNA**, **CTCs** and other analytes, liquid biopsy enables researchers to track the emergence of specific mutations or adaptive characteristics as they arise. A study in melanoma demonstrated that **CTC analysis provided additional genomic information to ctDNA in 68.8% of the samples**, identifying mutations in key melanoma pathways related to metastasis and therapeutic resistance, such as: - **BRAF** - **NRAS** - **CTNNB1** - **MAP2K1** Early prediction of treatment failure may enable trials to: 1. 'Fail fast' by providing an early endpoint when signs of resistance arise\ 2. Reduce costly later-stage failure\ 3. Identify biomarker-defined patient cohorts for inclusion or exclusion The **LIQUID IMPACT trial** highlights the potential of multi-analyte liquid biopsy for addressing tumour heterogeneity and resistance in advanced cancers. By measuring protein expression changes, such as **EGFR** and **mTOR overexpression**, the study demonstrated an ability to monitor key tumour characteristics. ------------------------------------------------------------------------ ### Challenge: patient stratification for precision medicine Accurate patient stratification is critical for targeted treatment and ensuring positive clinical trial outcomes. Multi-analyte liquid biopsy offers a comprehensive and non-invasive approach for revealing relevant **genetic**, **transcriptomic** and **proteomic** changes essential for targeted patient selection. The **ELIMA project** exemplifies this approach by analysing **CTCs**, **EVs** and **ctDNA** from a single blood sample. This method enabled the identification of patients who may benefit from specific therapies, such as the **PIK3CA inhibitor Alpelisib**, approved for metastatic breast cancer patients with **PIK3CA mutations detected in ctDNA**. Another clinical trial demonstrates that **proteomics from CTCs** can significantly enhance patient stratification by identifying patients most likely to benefit from advanced targeted therapies, such as **antibody drug conjugates (ADCs)**. Examples integrated into best practice include **AstraZeneca's multi-omic strategy**, integrating: - **Genomics** - **Transcriptomics** - **Proteomics** - **Metabolomics** ------------------------------------------------------------------------ ### Challenge: rising costs, regulatory pressures and drug pricing Developing a new drug requires substantial resources to meet strict regulatory standards for safety, efficacy and cost-effectiveness. Multi-analyte liquid biopsy offers a strategic advantage by: 1. Providing real-time molecular insights\ 2. Supporting early trial adaptations\ 3. Reducing costly late-stage failures A lung cancer trial at the **University of Arkansas for Medical Sciences (UAMS)** utilises liquid biopsy for longitudinal monitoring to improve efficiency and enable earlier detection of recurrence. Monitoring **CTCs** and **ctDNA** may serve as early surrogate endpoints for clinical outcomes, potentially shortening follow-up and reducing costs. ------------------------------------------------------------------------ ## Conclusion Multi-analyte and multi-omic liquid biopsy continues to demonstrate its potential in overcoming key challenges in the oncology space. The integration of liquid biopsy into clinical trials may pave the way for faster, more cost-effective drug development and improved regulatory compliance. By delivering precise, real-time molecular insights, liquid biopsy can enhance: - **Patient stratification** - **Treatment monitoring** - **Clinical trial efficiency** Current clinical trials are evaluating dual **CTC** and **ctDNA** analysis across multiple cancer types to stratify patients, monitor treatment response and enhance sensitivity in disease monitoring as compared to standard practice. Once approved, targeted drugs such as **ADCs**, **DNA damage response (DDR) inhibitors** and **immuno-oncology drugs** require targeted treatment selection through a companion diagnostic. Utilising liquid biopsy solutions will be critical to enable real-time, repeatable biomarker assessment to support regulatory clearance and reimbursement. ------------------------------------------------------------------------ ## References 1. Alix-Panabières C et al (2021), 'Liquid Biopsy: From Discovery to Clinical Application', Cancer Discov 11, pp858-873\ 2. 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Fehm T et al (2024), 'Efficacy of Lapatinib in Patients with HER2 Negative Metastatic Breast Cancer and HER2-Positive Circulating Tumor Cells-The DETECT III Clinical Trial', Clin Chem 70, pp307-318\ 19. Visit: astrazeneca.com/what-science-can-do/topics/disease-understanding/new-era-multi-omic-data-analysis-oncology.html\ 20. Visit: onclive.com/view/partner-perspectives-uams-winthrop-p-rockefeller-cancer-institute-pushes-liquid-biospy-research-forward ------------------------------------------------------------------------ ## Author Biographies **Karen Miller PhD**, chief scientific officer at **ANGLE plc**, has over 30 years' experience in the biotechnology and pharmaceutical industry, with a focus on drug discovery and clinical development in a wide range of indications including oncology. **Sydney Barrell** is a medical writer at **ANGLE plc**. Sydney holds a Master's degree in Genetics from the University of Sussex, UK, where his research focused on genome maintenance, replication fork proteins and chemotherapy resistance.