Vibecotamab  (Synonyms: XmAb14045)

Vibecotamab (XmAb14045) is a potent bispecific antibody targeting both CD123 and CD3. Vibecotamab targets T cell-mediated killing of CD123-expressing cells, regardless of T cell antigen specificity. Vibecotamab is a full length immunoglobulin molecule. Vibecotamab can be studied in research for diseases such as Myelodysplastic syndrome and acute myeloid leukemia. Recommend Isotype Control: half-IG G1-kappa/(scFv-heavy-lambda)-h-CH2-CH3^[1][2][3].

half-IGG1-kappa/(scFv-heavy-lambda)-h-CH2-CH3

Human IgG1 kappa, Isotype Control

Human

CD3E & IL3RA

Vibecotamb (Compound XmAb14045) stimulates T cell-mediated killing of CD123⁺ KG-1a and TF-1 AML cell lines (EC₅₀ = 8 pM)^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Vibecotamb (Compound XmAb14045) has a prolonged serum half-life in mice of 6.2 days^[3].
Vibecotamb (0.01-1 mg/kg, single dose) strongly activates T cells and stimulates depletion of over 99% of circulating CD123⁺ cells including basophils and plasmacytoid dendritic cells within 1 h of administration in cynomolgus monkey^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

916  [NCBI] & 3563  [NCBI]

P07766 & P26951

ELISA, FACS, Functional assay

Unconjugated

The product can be reconstituted/diluted with sterile PBS or saline.

126.15 kDa

2138442-13-2

Liquid

Colorless to light yellow

[Vibecotamab]

Shipping with dry ice.

Please refer to the lot-specific COA for specific buffer information.

Please store the product under the recommended conditions in the Certificate of Analysis.

• 
  half-IG G1-kappa/(scFv-heavy-lambda)-h-CH2-CH3

• 
  Immobilized Vibecotamab can bind Human CD3 epsilon/CD3e Protein (ECD, His Tag). The EC₅₀ for this effect is 0.48 ng/mL.
• 
  Immobilized Vibecotamab can bind Human IL-3R alpha/CD123 Protein (ECD, His Tag). The EC₅₀ for this effect is 7.66 ng/mL.
• 
  Flow cytometric analysis of 1×10⁶ Jurkat cells labelling CD3E (red) with Vibecotamab (HY-P99521). Cells were fixed with 4% paraformaldehyde and permeabilised with 90% methanol. Then stained with the primary antibody at 1/200 dilution for an hour at 4℃. Alexa Goat Anti-Human IgG H&L (AF488) (HY-P83776) was used as the secondary antibody at 1/1,000 dilution for 30 minutes at 4℃. Human IgG1 kappa Isotype Control (HY-P99001, blue) was used as the isotype control.

• [1]. FarhadRavandiMBBS, et al. Complete Responses in Relapsed/Refractory Acute Myeloid Leukemia (AML) Patients on a Weekly Dosing Schedule of Vibecotamab (XmAb14045), a CD123 x CD3 T Cell-Engaging Bispecific Antibody; Initial Results of a Phase 1 Study. Blood, Volume 136, Supplement 1, 5 November 2020, Pages 4-5

  [2]. Nicholas James Short et al., Meeting Abstract: 2023 ASCO Annual Meeting I, Journal of Clinical Oncology, Volume 41, Number 16

  [3]. Seung Y. Chu, et al., (2014) Immunotherapy with Long-Lived Anti-CD123 × Anti-CD3 Bispecific Antibodies Stimulates Potent T Cell-Mediated Killing of Human AML Cell Lines and of CD123+ Cells in Monkeys: A Potential Therapy for Acute Myelogenous Leukemia, Blood, Volume 124, Issue 21, Page 2316, ISSN 0006-4971.