Peptide and Oligonucleotides
Integrated Strategies for Two Complex Modalities
Peptide and oligonucleotide therapeutics can reach challenging biological targets with high specificity, but their physicochemical properties, stability, delivery, bioanalysis, and safety profiles require modality-specific development strategies. WuXi Biology and Testing integrates discovery biology, DMPK, bioanalysis, and safety assessment to support these modalities from early discovery through IND-enabling studies.
By aligning assay design, exposure assessment, biomarker planning, species selection, and safety evaluation, we help you connect biological activity with disposition and tolerability. This coordinated approach supports better candidate selection and more confident development decisions.
Shared Goals, Different Development Challenges
Peptides are short chains of amino acids that can provide high affinity and selectivity. Still, they may be limited by rapid enzymatic degradation, low permeability, short half-life, nonspecific adsorption, and immunogenicity. Oligonucleotides are short DNA- or RNA-based therapeutics that can affect RNA function or protein production. Still, they may require customized approaches to stability, delivery, tissue distribution, bioanalysis, immune response, and off-target evaluation.
Although the modalities differ, both benefit from early integration of discovery assays, DMPK, bioanalysis, biomarkers, and safety assessment. A stage-based strategy helps identify the right studies, methods, and decision points for each molecule.
Stage-Based Challenges and Solutions
Challenges
- Identifying hits with sufficient affinity, selectivity, and functional activity
- Balancing potency with stability, permeability, solubility, and manufacturability
- Optimizing linear, cyclic, and conjugated peptide formats
Solutions
- Peptide library screening using DEL, phage display, and mRNA display
- Biochemical and cell-based assays for potency and mechanism
- Structure-guided design, D2B optimization, and focused peptide library construction and synthesis
- Early stability, permeability, and physicochemical profiling
Challenges
- Selecting an appropriate RNA target and therapeutic format
- Balancing activity with stability, delivery, and off-target risk
- Comparing chemical modifications and conjugation strategies
Solutions
- Target validation and oligonucleotide design
- Custom synthesis, modification, and conjugation
- Cell-based activity, uptake, and functional assays
- Early cytotoxicity, immune-response, and off-target assessment
Challenges
- Rapid enzymatic degradation in biological matrices
- Poor permeability and high protein binding
- Nonspecific adsorption and complex metabolism
Solutions
- Stability testing in plasma, S9 fractions, hepatocytes, and simulated fluids
- Permeability and protein-binding assessment
- Metabolite profiling and soft-spot analysis
- Customized sample handling and assay conditions
Challenges
- Nuclease degradation and chemistry-dependent stability
- Adsorption, protein interactions, and complex extraction
- Limited predictability between in vitro and in vivo behavior
Solutions
- Matrix-specific stability and binding studies
- Optimized extraction and stabilization methods
- Metabolite profiling across relevant chemistries
- Delivery-system and conjugate characterization
Challenges
- Low or variable exposure across administration routes
- Complex tissue distribution and target-site delivery
- Species differences in metabolism and pharmacology
Solutions
- Route- and species-appropriate PK studies
- Disease-relevant pharmacology and PK/PD endpoints
- Tissue distribution, excretion, and radiolabeled studies
- Formulation and delivery assessment
Challenges
- Delivery-dependent distribution to liver, CNS, muscle, and other tissues
- Route-specific PK and duration of pharmacological effect
- Species selection based on the target and underlying biology
Solutions
- PK/PD studies across systemic and local routes
- Tissue sampling and biodistribution analysis
- Delivery-system assessment for conjugated and nanoparticle formats
- Translational efficacy studies in relevant models
Challenges
- Endogenous interference, matrix effects, and nonspecific binding
- Structural diversity requiring customized sensitivity and selectivity
- Need to evaluate metabolites and immunogenicity
Solutions
- LC-MS/MS, ligand-binding, and hybrid methods
- Fit-for-purpose sample preparation and validation
- Metabolite and biomarker analysis
- Anti-drug antibody testing when appropriate
Challenges
- Low concentrations and chemistry-specific extraction needs
- Parent compound, shortened products, and metabolites requiring differentiation
- Protein interactions and matrix components affecting quantitation
Solutions
- LC-MS/MS, LC-HRMS, qPCR, and hybridization-based methods
- Customized extraction and stabilization procedures
- Metabolite and tissue analysis
- Biomarker integration for exposure-response interpretation
Challenges
- Species relevance and immunogenicity
- Local tolerance and administration-route effects
- Potential off-target pharmacology and modified amino acid risks
Solutions
- Dose-range finding and safety pharmacology
- Repeat-dose studies with toxicokinetic and immunogenicity monitoring
- Genetic toxicology tailored to structural modifications
- Local tolerance, pathology, and clinical pathology
Challenges
- Innate immune activation, complement effects, and off-target activity
- Local reactions that vary by administration route
- Backbone and chemical modifications requiring tailored evaluation
Solutions
- Cytokine, immune-cell, and complement assessments
- Dose-range finding and toxicokinetic integration
- Repeat-dose studies with pathology and immune monitoring
- Genetic toxicology and local tolerance strategies tailored to the modality
Challenges
- Integrating DMPK, bioanalysis, pharmacology, and safety findings
- Addressing immunogenicity and route-specific considerations
- Maintaining clear data continuity for IND submissions
Solutions
- Coordinated study planning and program oversight
- Aligned bioanalytical, toxicokinetic, and safety strategies
- Regulatory consultation and integrated data packages
- Global capabilities that support submission readiness
Challenges
- Limited precedent across different oligonucleotide classes
- Evolving expectations for delivery, off-target, and immune effects
- Regional differences in study and documentation needs
Solutions
- Early regulatory strategy aligned to modality and route
- Cross-functional planning across DMPK, bioanalysis, and safety
- Cohesive interpretation of exposure, biomarkers, and toxicity
- Submission-ready reporting and documentation support
Integrated Planning Across Disciplines
Strong development strategies connect exposure, measurement, and safety rather than treating them as separate workstreams. DMPK data inform species and dose selection; bioanalysis measures parent compound, metabolites, biomarkers, and immunogenicity; and safety assessment interprets findings in the context of exposure and pharmacology.
Early cross-functional planning can reduce assay gaps, avoid unnecessary rework, and help ensure that studies answer the questions needed for candidate selection and IND readiness.
Flexible Support for Diverse Formats
Peptide capabilities support linear, cyclic, and conjugated formats, including peptide-drug conjugates and peptides used for targeted delivery. Oligonucleotide capabilities support ASOs, siRNA, aptamers, PMOs, CpG oligonucleotides, and conjugated or nanoparticle delivery approaches.
Our peptide and oligonucleotide testing capabilities are tailored to the molecule’s design, intended mechanism, route, matrix, species, and development stage, providing a flexible path from discovery through preclinical development.
Data Continuity From Discovery to IND
Method requirements change as a program advances. Exploratory assays may be appropriate for early screening. At the same time, later studies may require qualified or validated methods, controlled sample handling, and tighter integration of PK, PD, toxicokinetic, biomarker, and safety data.
By planning these transitions early, we help preserve scientific continuity across discovery, candidate selection, IND-enabling studies, and clinical development.
Related Services
Connect discovery, exposure, measurement, and safety capabilities in a coordinated strategy tailored to peptide and oligonucleotide therapeutics.
Discovery Biology
Support target selection, screening, functional assays, optimization, and disease-model evaluation tailored to each modality.
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DMPK
Characterize stability, permeability, PK, tissue distribution, metabolism, and delivery to understand exposure and disposition.
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Bioanalysis
Develop fit-for-purpose methods for quantitation, metabolites, biomarkers, immunogenicity, and PK/PD interpretation.
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Safety Assessment
Address species relevance, immune response, local tolerance, off-target risk, and modality-specific safety findings.
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Share your development goals and key challenges with our experts to define the right path forward.
Frequently Asked Questions
Peptide therapeutics are short chains of amino acids designed to interact with biological targets. Oligonucleotide therapeutics are short DNA- or RNA-based molecules designed to affect RNA function or protein production. Both can offer high specificity but require tailored discovery and development strategies.
Peptides can be rapidly degraded and may have limited permeability or short half-lives. Oligonucleotides may face stability, delivery, tissue distribution, off-target effects, and immune response challenges. Specialized assays and integrated planning help characterize these risks early.
Important studies may include stability, protein binding, permeability, PK, tissue distribution, metabolite profiling, excretion, and delivery-system assessment. The exact plan depends on the molecule, route, target tissue, and development stage.
Peptides may be quantified using LC-MS/MS, ligand-binding assays, or hybrid methods. Oligonucleotides may require LC-MS, qPCR, or hybridization-based assays. Method selection depends on sensitivity, selectivity, matrix, analyte form, and intended use.
Safety plans may address immunogenicity, innate immune activation, complement effects, off-target activity, local tolerance, administration-route findings, and risks associated with chemical modifications. Species and study design should reflect the modality and pharmacology.