We deliver Linker–Payload Development within an integrated CDMO framework spanning Pharmaceutical Development & Manufacturing→Drug Substance Development→Antibody-Drug Conjugate (ADC) Development. Our focus is laboratory biotechnology—designing, prototyping, and characterizing linker–payload systems that translate into manufacturable ADC drug substances with clear analytical control and reliable supply readiness.
Overview of Linker–Payload Development
The linker–payload defines the functional identity of an ADC drug substance: it governs liberation mechanics, catabolite profiles, hydrophobicity, and compatibility with common conjugation chemistries. We construct both cleavable and non-cleavable architectures, tune spacer length/rigidity, and incorporate masking elements to balance stability and solubility. Programs emphasize platformable chemistry, orthogonal analytics (LC–MS/MS, HIC, SEC, CE, peptide mapping), and small-scale DoE prototypes that de-risk later scale work without drifting into discovery. By aligning trigger chemistry (protease, β-glucuronide, acid, redox, glycosidase) with payload class (tubulin-interactive, DNA-reactive, topoisomerase-targeted), we minimize heterogeneity, control effective DAR tendencies once paired downstream.
Fig.1 Schematic of an ADC showing the antibody, attachment site, and the linker–payload segment clearly labeled.
Our Services
Our development offering into five integrated services that carry a concept from design through bench-scale prototypes and analytics.
Integrated Linker–Payload Design & Selection Service
We define trigger strategy, spacer topology, and self-immolative elements to meet targeted release and measurability requirements. Selection criteria include steric shielding, charge distribution, solubility, photostability, and known catabolic routes.
Cleavable & Non-Cleavable Engineering Service
We prototype protease-sensitive dipeptides, β-glucuronide triggers, acid-responsive motifs, and sterically tuned disulfides, alongside robust non-cleavable backbones for maximal systemic stability until lysosomal processing. Each candidate is supported by release-kinetics datasets, defined catabolites, stress-response mapping, and guidance on exchange liabilities. We also qualify stable surrogates that mirror fragmentation pathways to anchor release assays.
Biophysical Modulation & Conjugation-Mode Compatibility Service
To reduce aggregation risk post-conjugation, we apply hydrophilicity-enhancing masks (PEG segments, charged or zwitterionic units) and tune spacer rigidity/length for predictable reach and conformation. In parallel, we verify orthogonality to common downstream conjugation modes (cysteine, lysine, enzymatic tags, engineered handles), set acceptable process windows, and recommend ring-stabilization strategies that minimize maleimide exchange.
Stability & Analytical Enablement Service
We establish stability-indicating methods across ICH-aligned stressors and build LC–MS/MS assays for intact and released species with signature fragments or analytical surrogates. Packages include catabolite identification/quantitation, impurity narratives, specificity/linearity ranges, and intact profiling tools (HIC/SEC/CE).
We integrate design, engineering, biophysical tuning, analytical enablement, and manufacturability into a coherent linker–payload program. The outcome is a platform-ready, stability-informed package that de-risks downstream ADC drug-substance development. Contact us to align trigger chemistry, payload class, and analytical control.
Frequently Asked Questions
Q1: How do you control post-translational modifications that drive function?
We begin with desired liberation behavior and assayability, then evaluate payload stability and hydrophobicity constraints. Cleavables (protease, β-glucuronide, acid, redox) are favored for programmable release and clear catabolites; non-cleavables are selected when maximal systemic stability and reliance on lysosomal processing are preferred. Comparative stress data, HIC shifts, and LC–MS catabolite clarity finalize the choice.
Q2: Can highly hydrophobic payloads be accommodated without compromising downstream conjugation?
Yes. We apply PEGylated or charged masks, adjust spacer rigidity/length, and balance local polarity to reduce aggregation risk after conjugation while preserving functional-group accessibility.
Q3: What is typically included in a package prepared for internal CMC review?
Design rationale, reagent specifications, DoE summaries, stability-indicating methods, forced-degradation maps, impurity narratives, control strategies, and recommended specifications. Formatting aligns with ADC drug-substance documentation practices to streamline internal quality review and downstream planning.
Our products and services are for research use only.
