Osimertinib Mesylate API Suppliers & Bulk Manufacturers

Available Forms: API (drug substance)

Available Strengths: Supplied to an in-house or pharmacopoeial specification

Reference Brands: Tagrisso

Category: Active Pharmaceutical Ingredient

Osimertinib mesylate is a third-generation EGFR kinase inhibitor for EGFR-mutated lung cancer. It is sourced by generic formulators, CDMOs and licensed importers.

Product Description:

Osimertinib is a third-generation, irreversible EGFR tyrosine kinase inhibitor that targets the common sensitising EGFR mutations (exon 19 deletions and L858R) as well as the T790M resistance mutation. It is approved for EGFR-mutated non-small cell lung cancer in several settings: adjuvant treatment after surgery, after chemoradiation for unresectable stage III disease, first-line metastatic disease alone or with pemetrexed and platinum chemotherapy, and T790M-positive disease after an earlier EGFR inhibitor (reference brand: Tagrisso).

Specification at a glance

Regulatory files and timing

The FDA list of Drug Master Files (third quarter 2026) shows 6 active Type II API DMFs for this molecule. Few filings usually means few qualified sources, so early contact with suppliers pays off. For Europe, ask whether the supplier holds a CEP or an EU ASMF and, for imports into the EU, a written confirmation.

Generic or biosimilar entry. United States: Patent expiry; entry not confirmed (2032 (compound patent)). European Union: Patent expiry; entry not confirmed (2032 (compound patent + SPC)). Sources and updates are on our generic and biosimilar entry tracker.

Handling and quality points

Osimertinib is handled as a potent oncology API with defined occupational exposure controls. The acrylamide group that lets it bind irreversibly also means buyers should look at control of reactive and potentially mutagenic impurities, and the tertiary amines justify a nitrosamine risk assessment. As with any mesylate salt, ask for a statement on alkyl mesylate impurities, and confirm the crystal form of the salt by XRPD.

Send an API enquiry All specialty APIs

Brand names are trademarks of their respective owners and identify the reference medicine only. Information is general and was checked in October 2026; confirm specifications and filings with the supplier before purchase.