STX-721 free base · Synonyms: STX 721 · STX721

STX-721 is a mutant-selective inhibitor of EGFR.

For research use only. Not for human or veterinary use.

Target EGFR ERK

Research area Cancer

Purity >98% Stock Inquire

Data Sheet SDS COA

STX-721 structure

CAS No.: 2765525-82-2

Download structure (.mol)

Pack sizes & pricing

Size	Price	SKU	Stock
250 mg	USD 590.00	BP-02053-250mg	In stock	Get quote
500 mg	USD 945.00	BP-02053-500mg	In stock	Get quote
1 g	USD 1,520.00	BP-02053-1g	In stock	Get quote
5 g	Inquire	BP-02053-5g	In stock	Inquire

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Description

STX-721 is a mutant-selective inhibitor of EGFR and HER2 Exon 20 insertion (ex20ins) mutants.

Biological activity

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. 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. 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.

Identifiers

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
InChIKey: UMSJPISUMQOUKS-LMZGTLAXSA-N

Specifications

MW (average): 587.1120
Formula: C₃₂H₃₅ClN₆O₃
CAS No.: 2765525-82-2
Physical state: Solid
Color: Off-white to light yellow
Shipping: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.
Storage: Powder -20°C, 3 years , 4°C, 2 years ; In solvent -20°C, 1 month

Solubility

Soluble in DMSO : 100 mg/mL

Documents

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.

[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.

Same target

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Same research area

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