UCB develops medicines across three modality approaches: small molecules, large molecules and advanced therapeutics.Each approach draws on distinct research and development capabilities suited to its underlying science. This page explains what each approach involves, the capabilities that support it, and how we discover and develop new medicines. On this page (jump to a section)Small moleculesLarge moleculesAdvanced modalitiesOur capabilitiesFAQ Small molecules : new chemical entitiesSmall molecules are low molecular weight compounds that enter cells and modulate disease processes, whether in the periphery or the central nervous system. They remain the backbone of many of today's medicines. Oral bioavailability, low-cost manufacturing and the ability to reach targets inside the cell keep small molecules central to drug discovery.These compounds enter cells easily, acting directly on biological targets in the periphery or the central nervous system. AI-driven discovery, structure-based design, and high-throughput screening, including DNA-encoded and mRNA-display libraries, help our scientists find promising leads faster.The biology we can address keeps expanding. It now includes proximity-inducing approaches such as targeted protein degradation (PROTACs), peptide therapeutics such as macrocyclic peptides that pair small-molecule convenience with biologic specificity and a growing set of genetically validated targets. Large molecules: new biological entitiesLarge molecules are engineered biological medicines designed to target disease drivers precisely and engage the immune system. We have built deep expertise in antibody discovery and development through our new biological entity platform, which spans discovery, engineering, manufacturing and clinical application end to end.Single B cell technologies, automated deep immune sampling and phage and yeast display libraries help our teams identify high-quality antibody candidates quickly. Structural biology, molecular modelling and AI tools then support rational, and increasingly de novo, antibody design.Engineering is where our formats diverge. Antibody fragments, Fab-PEG technology and monovalent or bispecific formats such as TrYbe™ and BYbe™ are each tuned to a specific disease profile, improving tolerability, potency and therapeutic flexibility.Through structural biology, molecular modeling, and emerging AI tools, we continue to push the boundaries of rational antibody design. Advanced therapeutic modalitiesSome diseases require tools that act directly on their underlying biology rather than modulating it from outside. Our advanced therapeutic modalities are designed for exactly that: gene therapy, regenerative cell therapy and engineered immune biologics.Gene therapyGene therapy delivers therapeutic genes to cells or tissues to address genetic disease at its source, by replacing a faulty gene, adding one that fights disease, or silencing harmful genetic activity.We use a proprietary adeno-associated virus (AAV) capsid platform that targets specific cell and tissue types with precision, minimising off-target effects.It suits non-dividing or slowly dividing cells in the nervous system, skeletal muscle and liver - matching our severe neurological and neuromuscular disease expertise - while ongoing capsid engineering keeps improving scalability and cost.Regenerative cell therapyRegenerative cell therapy uses living cells as therapeutic agents to repair, restore or re-establish biological function, intervening directly within affected tissue rather than modulating disease from the outside.Our cell therapy approach is founded on regenerative neural cell technologies engineered into fully differentiated neuronal and glial cells designed to integrate permanently into existing neural circuits, replace missing or dysfunctional cells and modulate local electrical activity to restore physiological balance.Specialised inhibitory neurons and glial cells are central to neural circuit stability; their loss or dysfunction is implicated in disorders marked by pathological hyperexcitability, making targeted cellular replacement a precise, biologically grounded strategy.Engineered immune biologicsEngineered immune biologics redirect immune activity toward disease-driving mechanisms, aiming for durable benefit without broad immune suppression.The focus is B cell–directed T cell engagers: antibodies that engage T cells and selected B cell or plasma cell populations at once, for deeper, more sustained elimination of autoimmune-driving cells.Bispecific and multi-specific formats are optimized for potency, selectivity, and clinical usability, activating T cells in a controlled, antigen-independent way, and are developed as off-the-shelf therapies to support scalability, accessibility and a consistent patient experience. Our capabilitiesThe scientific skills, tools and teams listed below support every modality on this page, from target validation through to clinical delivery. ChemistryDesigns, synthesises and delivers new chemical entity clinical candidates, supports target validation with chemical tools and identifies PET ligands for translational science. Clinical developmentDesigns clinical studies from candidate selection through life cycle management, using technology and data to build in speed, efficiency and a participant-first approach. Clinical sciences and operationsExecutes, manages and collects data for clinical studies. Study physicians, medical writers, project managers and data specialists work together to deliver robust, high-quality results. Computer-aided drug discovery (CADD)Uses computational science and data analytics to accelerate high-quality drug candidates, contributing to the design of antibodies, small molecules and therapeutic proteins. Data science and advanced analyticsEmbedded across R&D, this team applies machine learning and AI to patient-level, clinical and molecular datasets - supporting target discovery, biological insight, predictive analytics and biomarker discovery. Development scienceBrings scientific and strategic expertise in non-clinical safety, quantitative pharmacology, drug metabolism and pharmacokinetics (DMPK) and translational biomarkers to drug discovery and development. Functional genomicsOur Element Genomics team (acquired in 2018) runs genetic screens to identify and validate novel targets, builds cellular models for translatability and elucidates small molecule mechanisms of action. Quantitative clinical pharmacologyIntegrates pharmacokinetics, pharmacodynamics, patient characteristics and disease biology through model-informed drug development, linking preclinical and clinical phases to optimise dosing and clarify benefit-risk for regulatory approval. Statistical sciences and innovationDevelops and deploys rigorous, innovative statistical methodology so resources go to the most impactful areas and new medicines reach patients faster. Translational medicineAn interdisciplinary partnership between researchers and clinicians that moves new medicines from bench to bedside, integrating biomarkers, clinical strategy and new technologies to sharpen disease understanding and inform late-stage development. Frequently asked questions Which therapeutic modalities do we work with? We work across three modality: small molecules (new chemical entities), large molecules (new biological entities) and advanced therapeutic modalities. The advanced group covers gene therapy, regenerative cell therapy and engineered immune biologics. What are small molecules in drug discovery? Small molecules are low molecular weight organic compounds, typically under 900 Daltons, that enter cells easily and modulate biological processes by binding to specific targets. They are chemically synthesised rather than biologically produced, are often orally bioavailable and can act on targets inside or outside the cell. What are PROTACs and how do they work? PROTACs, or proteolysis targeting chimeras, are small molecules that eliminate disease-causing proteins instead of simply inhibiting them. One end binds the target protein and the other recruits an E3 ubiquitin ligase, triggering degradation by the proteasome. This allows PROTACs to act catalytically and reach proteins once considered undruggable. What are macrocyclic peptides? Macrocyclic peptides are ring-shaped peptides that combine the target specificity of antibodies with the small size and stability of small molecules. The cyclic structure resists degradation and can bind difficult targets such as protein-protein interfaces. How do we discover antibodies? We use single B cell technologies, automated deep immune sampling and phage and yeast display libraries to identify antibody candidates quickly. Structural biology, molecular modelling and AI tools then support rational design, including de novo antibody creation. What are TrYbe™ and BYbe™ antibody formats? TrYbe™ and BYbe™ are antibody formats developed by us. TrYbe™ combines monovalent and bispecific target binding and is Fc-free by design, while BYbe™ achieves monovalent binding at very high protein concentrations. Both gain antibody-like half-life by binding albumin, an abundant and long-lived blood protein. How does our gene therapy approach work? Gene therapy delivers therapeutic genes to cells or tissues to address genetic disease at its source - by replacing a defective gene, adding a gene that combats disease or silencing harmful genetic activity. We use a proprietary adeno-associated virus (AAV) capsid platform suited to non-dividing or slowly dividing cells in the nervous system, skeletal muscle and liver. What is our approach to renegerative cell therapy? We use regenerative neural cell technologies to generate fully differentiated neuronal and glial cells. These cells are designed to integrate permanently into existing neural circuits, replace missing or dysfunctional cells and modulate local electrical activity to restore physiological balance. What is our approach to engineered immune biologics? Engineered immune biologics redirect immune activity toward disease-driving mechanisms, aiming for durable benefit without broad immune suppression. We focus on B cell–directed T cell engagers - bispecific antibodies that engage T cells and B cells or plasma cells simultaneously for deeper, more sustained elimination of the cells that drive autoimmune disease, developed as off-the-shelf therapies. Do we use artificial intelligence in drug discovery? Yes. We apply AI-driven discovery and structure-based design to small molecules, use AI tools to support rational antibody design and run a dedicated data science team applying machine learning to patient-level, clinical and molecular datasets for target discovery, predictive analytics and biomarker research. AI in pharmaceutical research is also explored on our science podcast, Hypothesize That!.
