Pucolentimab is a recombinant humanized monoclonal antibody targeting programmed cell death protein 1 (PD-1). It is also associated with the development code HX-008/HX008 and the marketed product name Puyouheng. Pucolentimab belongs to the IgG4 monoclonal antibody class and functions as an immune checkpoint inhibitor. IUPHAR identifies pucolentimab as an approved anti-PD-1 antibody, while FDA's Global Substance Registration System identifies the corresponding substance as a complete IgG4 monoclonal antibody.
The substance is associated with CAS Number 2403647-03-8 in the FDA GSRS record. FDA GSRS gives an estimated molecular formula of C6424H9924O2008N1708S48 and an estimated average molecular weight of approximately 145,000 Da. Because monoclonal antibodies are large heterogeneous biological molecules, molecular weight is appropriately expressed as an approximate protein molecular mass rather than the precise molecular weight normally used for small-molecule APIs.
Product Name: Pucolentimab
Alternative Database Name: Pucotenlimab
Development Code: HX-008 / HX008
CAS Number: 2403647-03-8
Protein Type: Monoclonal Antibody
Antibody Class: Humanized IgG4
Target: Programmed Cell Death Protein 1 (PD-1)
Molecular Weight: Approximately 145 kDa
Estimated Molecular Formula: C6424H9924O2008N1708S48
Biological Class: Immune checkpoint inhibitor
FDA GSRS classifies the substance as a protein and specifically as a monoclonal antibody, IgG4, with the sequence type recorded as complete.
Pucolentimab is designed to bind PD-1 and prevent interaction between PD-1 and its ligands PD-L1 and PD-L2. Blocking this immune checkpoint can restore T-cell-mediated antitumor activity. IUPHAR describes pucolentimab as an anti-PD-1 immune checkpoint inhibitor with minimal FcγRIIIa and C1q binding.
Pucolentimab is a complex biological API rather than a conventional chemically synthesized small molecule. Its quality is therefore evaluated using a combination of identity, purity, potency, protein concentration, aggregation, charge heterogeneity, glycosylation and biological activity assays.
The antibody contains the characteristic structural features of an IgG4 therapeutic antibody. Published research describes pucolentimab as a humanized IgG4 anti-PD-1 monoclonal antibody with an S228P hinge mutation and engineered Fc domain.
For biological API manufacturing, control of the production cell system, upstream processing, downstream purification, viral clearance, filtration, formulation and storage conditions is essential. Analytical characterization is generally performed using orthogonal methods rather than relying on a single chemical assay.
Pucolentimab targets PD-1, an immune checkpoint receptor expressed on activated immune cells. Binding of PD-1 by its ligands PD-L1 and PD-L2 can suppress T-cell activity. Pucolentimab blocks these interactions, supporting reactivation of immune-mediated antitumor responses.
Pucolentimab received conditional approval in China in July 2022 for specified patients with unresectable or metastatic MSI-H/dMMR solid tumors, including advanced colorectal cancer following specified prior therapies. IUPHAR also records subsequent expansion to unresectable/metastatic melanoma that is unresponsive to previous systemic therapy.
Clinical development has also investigated pucolentimab across a range of advanced solid tumors. A Phase I study evaluated intravenous administration in patients with advanced solid tumors and investigated safety, pharmacokinetics, immunogenicity and preliminary antitumor activity.
As a monoclonal antibody, Pucolentimab should not be evaluated using a conventional small-molecule API specification such as a simple HPLC assay percentage. Instead, a biological quality-control strategy may include:
These tests should be controlled according to the validated product-specific biological specification rather than applying numerical small-molecule API limits.
Manufacturing Pucolentimab requires specialized biologics manufacturing capabilities and strict process controls. Unlike conventional pharmaceutical APIs, monoclonal-antibody production generally involves mammalian cell culture, controlled bioreactor processing, harvest clarification and multiple purification stages.
Critical manufacturing controls may include cell-bank qualification, upstream process monitoring, chromatography-based purification, viral inactivation and clearance, sterile filtration and controlled formulation.
The quality of a monoclonal antibody is closely linked to the manufacturing process. Consequently, product-specific analytical methods and validated biological assays are essential for demonstrating identity, purity, consistency and potency.
Pucolentimab is a biological protein and therefore requires controlled storage conditions established through product-specific stability studies. Exposure to excessive temperature, agitation, inappropriate pH or other environmental stresses can affect protein structure, aggregation and biological activity.
The final storage temperature, container-closure system, concentration and formulation should therefore follow the validated product specification. Numerical storage conditions should not be presented as a universal API value unless supported by the applicable product documentation.
Typical documentation for a monoclonal-antibody API may include:
Pucolentimab is a specialized humanized IgG4 anti-PD-1 monoclonal antibody associated with immune checkpoint inhibition. Its biological nature makes comprehensive characterization and process control essential.
The API's identity, purity, structural characteristics and biological activity require appropriately validated analytical techniques. A robust manufacturing and quality-control program can support consistent production of this complex biological substance for pharmaceutical development and regulated applications.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |