Insights from ESMO 2026: New Directions in Oncology Biomarker Research and Treatment

How can researchers identify the right biomarkers, develop more targeted treatments, and make sense of increasingly complex biological data? These were among the questions explored at ESMO Congress 2026 in Madrid.

Colleagues from across our teams specializing in biopharma, histopathology, and specialty lab attended the congress, joining researchers, clinicians, drug developers, and industry experts to discuss the challenges facing oncology research and the opportunities emerging across the field.

Conversations across biomarker development, antibody-drug conjugates (ADCs), cell therapies, liquid biopsy, and artificial intelligence (AI) reflected a field working with increasingly complex biological data – and looking for better ways to translate it into decisions for patients.

Read on for a closer look at the key discussions and what they mean for oncology research and clinical trial development.

Biomarker strategies move beyond single markers

Discussions with researchers at ESMO showed a growing interest in bispecific antibodies targeting multiple biomarkers to enhance therapeutic efficacy and overcome resistance mechanisms.

In her presentation, “Biology and mechanisms of action of novel immunotherapies,” Tina Cascone, Director of Translational Research at the University of Texas MD Anderson Cancer Center, showed that immune checkpoint targets such as CTLA-4, TIGIT, TIM-3, and LAG-3 are increasingly being incorporated into bispecific formats with the aim of enhancing anti-tumor activity and overcoming resistance mechanisms. Alongside these therapeutic advances, combining multiple biomarkers can help researchers understand different pathways, support patient stratification, and inform the development of targeted therapies.

This has implications for how studies approach testing. Tissue, cellular, and molecular assays may all contribute to understanding a tumor and its surrounding immune environment. Selecting appropriate methods and considering how their results fit together can help ensure the testing strategy addresses the study’s biological objectives.

However, despite their promise, treatment-related toxicity remains a significant challenge. In his presentation, “Management of toxicities from next generation immunotherapies,” medical oncologist and researcher Roberto Ferrara explored how toxicity risks can increase as multiple immune targets are engaged simultaneously.

ADCs bring biomarker selection into sharper focus

ADCs featured prominently at the congress, reflecting continued interest in their role across oncology development. Sessions explored next-generation ADCs and new therapeutic combinations, as well as the use of established biomarkers to identify patient populations that may be more likely to benefit. Many of these sessions focused on individual tumor types, including endometrial cancer, sarcoma, prostate cancer, colorectal cancer, renal cell carcinoma, gynecologic cancers, and pancreatic cancer.

As ADC programs become more targeted, biomarker assessment plays an important role in study design. Understanding the expression and relevance of therapeutic targets in the populations being studied helps inform patient selection, while appropriate testing approaches support the interpretation of clinical data.

The development of new ADCs also brings greater focus to how tumors are characterized. Testing approaches need to account for the therapy’s mechanism of action and the specific questions each clinical program aims to answer.

Cell therapy development explores new models

Cell therapy was another popular topic of discussion. In their session “Proffered paper: Developmental therapeutics,” Lui Chang presented results from a promising targeted Guanylyl cyclase C (GUCY2C) CAR-T, highlighting GUCY2C as biomarker and therapeutic target for patients with colorectal cancer.

Alongside advances in chimeric antigen receptor T-cell (CAR-T) therapy, the congress highlighted approaches intended to improve treatment accessibility and scalability, including allogeneic leukocytes, or “off-the-shelf” therapy derived from healthy donors, as presented by George Tetz, CEO at Second Life Group.

Unlike autologous therapies, which use a patient’s own cells, allogeneic approaches use donor cells prepared in advance for potential use across multiple patients. This could help address some of the manufacturing and logistical challenges associated with personalized cell therapies, although their clinical application continues to be evaluated.

The characteristics of each cell therapy also shape the testing required during development. This can include assessing cell phenotype and activity, tracking persistence, and monitoring relevant safety markers. The assays selected will depend on the product itself and the questions being addressed at each stage of clinical development.

Liquid biopsy and ctDNA continue to develop

Liquid biopsy remained an active topic at ESMO, particularly the use of circulating tumor DNA (ctDNA) to monitor treatment response and inform clinical decision-making, including in immunotherapy programs. It featured both broadly and in dedicated sessions, including “ctDNA in colorectal cancer: State-of-the-art and evolving clinical applications,” delivered by medical oncologist Jeanne Tie from the Peter MacCallum Cancer Centre.

The approach offers the possibility of assessing tumor-associated genetic material from a blood sample, rather than relying solely on tissue biopsies. Discussions covered its use for relapse monitoring, prognostic assessment after surgery, and as a marker to guide the selection of specific treatments. However, sensitivity remains an important consideration, especially when tumor burden is low. The amount of ctDNA available for analysis can affect whether a signal is detected and how results should be interpreted.

The value of ctDNA testing depends on the sensitivity of the assay and how results are interpreted in the context of the study. Combining ctDNA findings with other clinical and biomarker data can help build a broader understanding of disease status and treatment response.

More comprehensive datasets raise new analytical questions

Researchers are using approaches such as flow cytometry, multiplex tissue analysis, sequencing, and other omics technologies to examine more features of a sample and build a broader picture of tumor and immune biology.

These methods generate high-dimensional datasets, but more measurements do not automatically produce clearer answers. Data quality, assay validation, standardized analysis, and appropriate interpretation all influence how findings can be compared and applied to development decisions.

For sponsors, this places greater emphasis on planning how different data types will be generated and analyzed from the outset. Aligning sample requirements, assay selection, and analytical methods can help ensure that complex datasets remain relevant to the questions a trial is designed to address.

AI brings new possibilities for analyzing oncology data

The session “Transforming Oncology with Generative AI and Autonomous Tools” explored how AI is creating new opportunities across oncology research, from biomarker identification and patient selection to pathology image analysis and drug discovery. Separately, a rapid oral session on developmental therapeutics featured the first-in-human, multicenter phase I study of ISM6331, an AI-designed pan-TEAD inhibitor, in patients with mesothelioma and other advanced solid tumors.

By helping researchers identify patterns across complex datasets, these tools could provide additional insight into tumor biology and support the interpretation of increasingly detailed molecular and cellular data.

However, the value of AI depends on the quality and representativeness of the data used to train and validate models, as well as whether the outputs are scientifically meaningful in the context of the study. Expert review is essential, particularly when AI-generated findings could influence clinical research decisions.

What these developments mean for oncology trials

The themes at ESMO 2026 point to an increasingly integrated approach to oncology research.

Advances in biomarker research, cell therapies, liquid biopsy, and data analysis are expanding the role of laboratory testing in oncology trials. Generating meaningful results requires careful consideration of assay selection, sample requirements, validation, and data interpretation, supported by scientific input that connects testing strategies to the biological questions and development needs of each study.

Developing an oncology biomarker strategy or planning testing for a clinical trial? Talk with our team about aligning the right assays, technologies, and lab support with your study objectives.