We operate within an integrated hierarchy—from Pharmaceutical Development & Manufacturing to Drug Substance Development and then to Cytokine Development—to deliver rigorous, lab-centered programs for recombinant thrombopoietin (TPO). Our focus is disciplined upstream and downstream development that readies TPO candidates for reliable, specification-driven manufacture.
Overview of Thrombopoietin (TPO) Development
Thrombopoietin is a glycoprotein cytokine that engages MPL (TPOR) and triggers JAK–STAT pathways in dedicated bioassays. Unlike many simple recombinant proteins, TPO's performance is highly sensitive to glycoform distribution, sialylation, and structural integrity, which in turn are shaped by cell line, process parameters, and purification design. Effective development therefore demands alignment of sequence strategy, expression host, and orthogonal analytics that quantify identity, purity, potency, and stability. We build scale-conscious, research-grade processes in small, well-controlled increments so that TPO drug substance can progress smoothly through later manufacturing stages.
Our Services
We provide a coherent suite of CDMO services span sequence and expression design, upstream prototyping, purification development, and analytical method establishment work.
Sequence & Variant Engineering Service
We evaluate native and engineered TPO constructs for manufacturability and target biology, including signal peptides, propeptide considerations, receptor-binding regions, and fusion partners (e.g., Fc or albumin domains for half-life extension). Work includes codon optimization per host, assessment of predicted PTMs, disulfide pairing, and in silico liability screening to mitigate deamidation, oxidation, and proteolysis.
Expression System Development Service
We develop transient and stable expression in mammalian systems (CHO or HEK lines, as appropriate) with media and feed tailored to TPO glycosylation. Activities cover vector design, clone screening, titer enhancement, and small-bioreactor runs for parameter scouting (pH, temperature shift, dissolved oxygen). We quantify productivity, product quality, and key impurities (HCP/DNA) to identify a robust, scalable starting point.
Upstream Process Prototyping Service
We translate bench expression into controlled mini-bioreactor workflows to characterize CQAs versus process inputs. Using DoE where useful, we map the design space for glycan distribution, sialylation retention, and aggregation avoidance.
Purification Development Service
We construct platform-style downstream trains suitable for glycoproteins, typically combining capture (affinity or ion-exchange), polishing (IEX, HIC, SEC as needed), and virus clearance steps consistent with cytokine drug-substance norms. Resin screening emphasizes recovery, host impurity clearance, and preservation of active, properly folded TPO.
Analytical & Potency Method Development Service
We establish identity, purity, and higher-order-structure methods: intact/reduced LC–MS, peptide mapping, glycan profiling (released and site-specific), CE-SDS, SEC-MALS, and charge variants. For bioactivity, we develop cell-based potency assays reflecting MPL engagement and downstream phosphorylation/viability readouts, supported by system suitability and reference-standard governance.
Our Thrombopoietin (TPO) Portfolio
Our development services support common, tractable TPO drug-substance categories that align with mainstream cytokine development practice, including but not limited to:
- Native Full-Length Human TPO Constructs: Secreted glycoprotein, mammalian-expressed.
- Glycoengineered TPO: Sialylation-optimized and charge-variant–managed profiles.
- TPO Fc-fusion Proteins: Format-agnostic designs for extended systemic persistence.
- TPO albumin-Fusions: Half-life extension while maintaining receptor engagement.
- PEGylated TPO Formats: Controlled-site PEG conjugation compatible with activity.
- Species-relevant TPO Variants: Murine, rat, NHP orthologs for nonclinical model continuity.
- Receptor-binding Domain–focused TPO Constructs: Engineered fragments retaining MPL activity.
- Long-acting TPO with Unstructured Polypeptide Extensions: XTEN-like architectures where permissible.
We deliver end-to-end, laboratory-centered TPO drug-substance development within a rigorous pharmaceutical framework. Contact us to initiate a focused development plan.
Frequently Asked Questions
Q1: Which expression host is most suitable for TPO, and how do you control glycosylation?
We typically recommend mammalian systems (CHO or HEK) due to their mature glycosylation machinery. We tune media, feeds, temperature shifts, and harvest timing to influence sialylation and charge variants. Glycan outcomes are measured by released and site-specific LC–MS profiling and linked to potency through cell-based assays. For programs prioritizing a particular glycoform distribution, we apply DoE-driven parameter mapping to define reproducible operating ranges.
Q2: How is TPO potency measured during development?
We implement a cell-based bioassay reflective of MPL signaling, using qualified reference standards and system-suitability controls. Readouts may include receptor-proximal phosphorylation or proliferation/survival endpoints. Parallel analytics (e.g., intact mass, glycan mapping, and aggregation by SEC-MALS) are correlated to potency to ensure the assay tracks structure–function relationships across lots and stress conditions.
Q3: What strategies reduce TPO aggregation and maintain higher-order structure?
We address aggregation at multiple layers: sequence liability review, upstream control of stressors (pH, temperature, shear), and purification trains that avoid conditions promoting partial unfolding. Formulation screens identify buffers and excipients that stabilize TPO against thermal and interfacial stress. We confirm outcomes via SEC-MALS, DLS, FTIR or CD, and stress-challenge studies to establish formulation robustness.
Our products and services are for research use only.
