Cat. No.: HY-157229

STX-721

1 Cited Publications

Customer Review

Based on 1 publication(s) in Google Scholar

STX-721 is an orally active, irreversible, covalent EGFR exon 20 insertion (ex20ins) inhibitor that selectively targets ex20ins-mutant dynamic protein states. STX-721 potently inhibits the kinase activity of EGFR ex20ins mutants (NPG, ASV, SVD). STX-721 inhibits phosphorylation of EGFR (pEGFR Y1068) and downstream ERK (pERK Thr202/Tyr204), and suppresses proliferation of ex20ins-mutant Ba/F3 cells and human NSCLC cell lines (NCI-H2073 ASV KI, CUTO-14 ASV). STX-721 induces tumor regression in EGFR ex20ins-mutant PDX/CDX models. STX-721 can be used for the study of non-small cell lung cancer (NSCLC) harboring EGFR or HER2 ex20ins mutations.

For research use only. We do not sell to patients.

Purity: 98.25%
CAS No.: 2765525-82-2
Formula: C₃₂H₃₅ClN₆O₃
Molecular Weight:587.11

Storage:

Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 6 months , -20°C, 1 month

STX-721 Chemical Structure

CAS No.: 2765525-82-2

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Antibody-Drug Conjugates

One-stop solution for XDC (ADC/PDC/RDC/ApDC/FDC/ISAC/VDC/SMDC)

Biological Activity
- Description
- Cellular Effect
- In Vitro
- In Vivo
Chemical Information
Publications (1)
Solvent & Solubility
- In Vitro
Purity & Documentation
References
Help & FAQs
Classifications
Bioz

Biological Activity

Description

All EGFR Isoforms :

All ERK Isoforms :

Cellular Effect

Cell Line	Type	Value	Description	References
BaF3	IC₅₀	136.7 nM Compound: STX-721	Antiproliferative activity against mouse BaF3 cells harboring wild type EGFR Antiproliferative activity against mouse BaF3 cells harboring wild type EGFR	[PMID: 37669428]
BaF3	IC₅₀	5.17 nM Compound: STX-721	Antiproliferative activity against mouse BaF3 cells harboring EGFR-D770-N771insNPG mutant Antiproliferative activity against mouse BaF3 cells harboring EGFR-D770-N771insNPG mutant	[PMID: 37669428]

In Vitro

STX-721 (10-1000 nM, 2 h) inhibits phosphorylation of EGFR (pEGFR Y1068) and ERK (pERK Thr202/Tyr204) in patient-derived EGFR exon 20 insertion-mutant cell lines (MGH10080-1 SVD, MGH10022-1.19 GF) with higher potency than in EGFR WT NCI-H2073 cells^[1].
STX-721 (72 h) shows antiproliferative activity in CRISPR/Cas9-edited NCI-H2073 human cancer cell lines, with IC₅₀ values of 10.1 nM for NCI-H2073 EGFR V769_D770 insASV knock-in (KI) cells and 6.1 nM for NCI-H2073 EGFR D770_N771 insSVD KI cells^[2].

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

In Vivo

STX-721 (12.5-100 mg/kg, p.o., once daily, 20-42 days) demonstrates excellent anti-tumor efficacy in EGFR ex20ins-mutant PDX/CDX models.^[1].

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

Animal Model:

Tumor tissues with NSCLC harboring EGFR NPH mutation, EGFR ASV mutation, EGFR SVD mutation, HER2 YVMA mutation and NCI-H2073 EGFR_exon20_SVD_ins cells (1×10⁷ cells/mouse in appropriate medium) were subcutaneously implanted into the flanks of 6-8-week-old female BALB/c nude mice^[1]
Dosage:

12.5, 25, 50, 100 mg/kg
Administration:

p.o. once daily for 20, 26, 38 or 42 days
Result:

Achieved tumor growth inhibition.
Reduced phosphorylation of EGFR (pEGFR) and ERK (pERK).

Chemical Information

CAS No. 2765525-82-2
Appearance Solid
Molecular Weight 587.11
Formula C₃₂H₃₅ClN₆O₃
Color Off-white to light yellow
SMILES

O=C(N1CCC[C@]1(C)C#CC2=C(C=CN=C2)C3=C(C4=C(N3)CCNC4=O)NC5=CC=CC(Cl)=C5OC)/C=C/CN(C)C
Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	6 months
	-20°C	1 month

Publications (1)

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Cancer Discov

Sevabertinib, a Reversible HER2 Inhibitor with Activity in Lung Cancer. [Abstract]

2025 Oct 15. PMID: 41090369

Solvent & Solubility

In Vitro:

DMSO : 100 mg/mL (170.33 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

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Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

1.7033 mL

8.5163 mL

17.0326 mL

5 mM

0.3407 mL

1.7033 mL

3.4065 mL

10 mM

0.1703 mL

0.8516 mL

1.7033 mL

Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.

Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

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Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (284 KB)
SDS (251 KB)
- English - EN (251 KB)
- Français - FR (251 KB)
- Deutsch - DE (251 KB)
- Norwegian - NO (251 KB)
- Español - ES (251 KB)
- Swedish - SV (251 KB)
- Italian - IT (251 KB)
- Korean - KR (251 KB)
- Portuguese - PT (251 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. Pagliarini RA, et al. STX-721, a Covalent EGFR/HER2 Exon 20 Inhibitor, Utilizes Exon 20-Mutant Dynamic Protein States and Achieves Unique Mutant Selectivity Across Human Cancer Models. Clin Cancer Res. 2025 Jul 15;31(14):3002-3018. [Content Brief]

[2]. Milgram BC, et al. Discovery of STX-721, a Covalent, Potent, and Highly Mutant-Selective EGFR/HER2 Exon20 Insertion Inhibitor for the Treatment of Non-Small Cell Lung Cancer. J Med Chem. 2025 Feb 13;68(3):2403-2421. [Content Brief]

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
DMSO	1 mM	1.7033 mL	8.5163 mL	17.0326 mL	42.5815 mL
	5 mM	0.3407 mL	1.7033 mL	3.4065 mL	8.5163 mL
	10 mM	0.1703 mL	0.8516 mL	1.7033 mL	4.2581 mL
	15 mM	0.1136 mL	0.5678 mL	1.1355 mL	2.8388 mL
	20 mM	0.0852 mL	0.4258 mL	0.8516 mL	2.1291 mL
	25 mM	0.0681 mL	0.3407 mL	0.6813 mL	1.7033 mL
	30 mM	0.0568 mL	0.2839 mL	0.5678 mL	1.4194 mL
	40 mM	0.0426 mL	0.2129 mL	0.4258 mL	1.0645 mL
	50 mM	0.0341 mL	0.1703 mL	0.3407 mL	0.8516 mL
	60 mM	0.0284 mL	0.1419 mL	0.2839 mL	0.7097 mL
	80 mM	0.0213 mL	0.1065 mL	0.2129 mL	0.5323 mL
	100 mM	0.0170 mL	0.0852 mL	0.1703 mL	0.4258 mL

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STX-721

Immunology/Inflammation Compound Library

JAK/STAT Compound Library

Kinase Inhibitor Library

MAPK Compound Library

Protein Tyrosine Kinase Compound Library

Stem Cell Signaling Compound Library

Anti-Cancer Compound Library

Anti-Aging Compound Library

Covalent Screening Library

Differentiation Inducing Compound Library

Reprogramming Compound Library

Oxygen Sensing Compound Library

Orally Active Compound Library

Glutamine Metabolism Compound Library

Anti-Hepatitis C Virus Compound Library

Anti-Lung Cancer Compound Library

Anti-Pancreatic Cancer Compound Library

Anti-Obesity Compound Library

Angiogenesis-Related Compound Library

Anti-Liver Cancer Compound Library

Anti-Colorectal Cancer Compound Library

Anti-Prostate Cancer Compound Library

Cancer Stem Cells Compound Library

Pain-Related Compound Library

Membrane Protein-targeted Compound Library

Membrane Receptor-targeted Compound Library

Highly Selective Inhibitors Library

Cytokine Inhibitors Library

Serine/Threonine Kinase Inhibitor Library

Anti-Ovarian Cancer Compound Library

Multi-Target Compound Library

Bioactive Compound Library Max

MCE Bioactive Compound Library

Covalent Screening Library Plus

Bioactive Compound Library

Anti-Brain Cancer Compound Library

Protein Kinase Compound Library

Cell Proliferation Compound Library

High-Throughput Bioactive Compound Library

Posttranslational Modification Library

Lactylation Compound Library

Alkyne Compound Library

Publications Citing Use of MedChemExpress (MCE) STX-721

All EGFR Isoforms

All ERK Isoforms

Biological Activity

Chemical Information

Publications (1)

Solvent & Solubility

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

STX-721 Related Classifications

HY-157229 Related Classifications