KB-1354

ARX517-hIgG1

33675

Background of ARX517-hIgG1

Prostate cancer is the most prevalent cancer and the second leading cause of cancer-related deaths among men in the United States. Metastatic castration-resistant prostate cancer (mCRPC) is an advanced stage of the disease, characterized by the failure of androgen-deprivation therapies and a low survival rate. Recently, the prostate-specific membrane antigen (PSMA) has been identified as a tumor antigen in prostate cancer, showing high expression in tumors and low expression in normal tissues. Ambrx has developed ARX517, an engineered precision biologic (EPB) that utilizes an expanded genetic code. ARX517 is an anti-PSMA targeted next-generation antibody drug conjugate (ADC) designed for the treatment of mCRPC patients. It consists of a humanized anti-PSMA antibody that is specifically conjugated to the drug linker AS269, a potent tubulin inhibitor. This results in a drug-to-antibody ratio of 2. Once ARX517 binds to PSMA on the surface of tumor cells, it is internalized and releases a cytotoxic payload that inhibits tubulin polymerization and induces cellular apoptosis.

Specifications

Catalog Number	KB-1354
Antibody Name	ARX517-hIgG1
Isotype	Human IgG1,kappa
Target	PSMA
Species Reactivity	Human
Host Cell Line	EXPI CHO
Purification Method	Affinity purified
Concentration	>2 mg/mL
Formulation	50 mM sodium citrate,150mM NaCl,pH5.5
Purity	>95% by SDS-PAGE and SEC-HPLC
Validation	ELISA
Endotoxin Level	<0.2 EU/mg as determined by the LAL method
Sterility	0.2μm filtered
Storage	It is recommended that the protein should be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.
Stability	Stable for twelve months from date of receipt when stored at -20°C to -80°C; Stored at 2-8°C for one month without detectable loss of activity.

Characterization

Application

References

hen J, Pachynski R, Nordquist LT, et al. APEX-01: First-in-human phase I/II study of ARX517 an anti- prostate-specific membrane antigen (PSMA) antibody-drug conjugate (ADC) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC). Ann Oncol. 2023;34(suppl 2):S974-S975. doi:10.1016/j.annonc.2023.09.2752
FDA grants Fast Track Designation for Ambrx’s ARX517 for the treatment of metastatic castration-resistant prostate cancer. News release. Ambrx Biopharma Inc. July 19, 2023. Accessed October 25, 2023.