Osimertinib Mesylate

Osimertinib Mesylate is a pivotal pharmaceutical active pharmaceutical ingredient (API) and certified reference standard in the treatment of non-small cell lung cancer (NSCLC) harboring activating EGFR mutations (exon 19 deletions or L858R) and the T790M resistance mutation. As the active pharmaceutical ingredient in Tagrisso®, Osimertinib Mesylate was approved by the U.S. FDA in November 2015 and has since become the first-line standard of care for EGFR-mutant NSCLC. Beyond its therapeutic role, Osimertinib Mesylate serves as an essential analytical reference standard in quality control laboratories, where it is used for analytical method development, method validation (AMV), and quality control (QC) applications for Abbreviated New Drug Applications (ANDA). The compound’s high purity specifications — with maximum single impurity ≤0.20% and total impurities ≤1.00% — make Osimertinib Mesylate an indispensable reference material for impurity profiling, forced degradation studies, and commercial production of osimertinib-containing drug products. In research contexts, Osimertinib Mesylate is extensively utilized as the definitive comparator compound for studying EGFR TKI resistance mechanisms, CNS metastasis models (achieving a brain/blood AUC ratio of 3.8), and the development of next-generation EGFR inhibitors.

 

Product Parameters

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Parameter	Specification
Product Name	Osimertinib Mesylate
CAS Number	1421373-66-1
Molecular Formula	C₂₉H₃₇N₇O₅S
Molecular Weight	595.72 g/mol
Appearance	Off-white to yellow powder
Storage Condition	-20°C Freezer, Under inert atmosphere

 

Synthetic Route

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N-(4-fluoro-2-methoxy-5-nitrobenzene)-4-(1-methyl-1H-indol-3-yl)pyrimidine-2-chloride was synthesized by reacting 4-fluoro-2-methoxy-5-nitroaniline with 3-(2-chloropyrimidin-4-yl)-1-methylindole under the catalysis of a monohydrate compound. The fluorine group was subsequently replaced by N,N,N'-trimethylethylenediamine, followed by reduction of the nitro group with ammonium iron. After reaction with 3-chloroacetyl chloride and elimination, AZD9291 was obtained with a yield of 17.5%. AZD9291 was further salted with methanesulfonic acid to yield AZD9291 methanesulfonate.

 

New drug for non-small cell lung cancer – Osimertinib

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On November 13,2015, the U.S. FDA approved the oral tablet formulation of Osimertinib (brand name Tagrisso) developed by British pharmaceutical company AstraZeneca through the Priority Review pathway. It is indicated for the treatment of patients with advanced non-small cell lung cancer (NSCLC) harboring the epidermal growth factor receptor (EGFR) T790M mutation or resistance to other EGFR inhibitors. Prior to clinical use of the EGFR inhibitor Osimertinib, testing for the presence of the T790M mutation must be performed in all patients. Only NSCLC patients with the T790M mutation are eligible for targeted therapy with Osimertinib.

 

Bioactivity

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Osimertinib mesylate (AZD9291) is the mesylate salt of osimertinib and an oral third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI).

 

Contact Us

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Need Osimertinib Mesylate for your NSCLC drug development program, impurity profiling initiative, or ANDA filing? Cosperpharm is ready to support your project with high‑quality material and comprehensive documentation. Reach out today — we‘re here to help.