Ravtansine (DM4) API Suppliers & Bulk Manufacturers

Available Forms: API (drug substance)

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

Reference Brands: Elahere

Category: Active Pharmaceutical Ingredient

Ravtansine (DM4) is a maytansinoid cytotoxic used as the payload in antibody-drug conjugates. It is sourced by ADC developers, conjugation CDMOs and oncology R&D teams.

Product Description:

Ravtansine, widely known as DM4, is a thiol-bearing maytansinoid that binds to tubulin and stops cancer cells dividing; it is too toxic to give on its own, so it is linked to antibodies that carry it to tumour cells. The approved conjugate that uses the DM4 payload, attached through a sulfo-SPDB disulfide linker (named soravtansine in that product), is indicated for folate receptor alpha-positive, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer after one to three prior systemic treatments (reference brand: Elahere).

Specification at a glance

Regulatory files and timing

The FDA list of Drug Master Files (third quarter 2026) shows 0 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: No confirmed date. European Union: No confirmed date.

Handling and quality points

DM4 is extremely potent and must be handled in isolators with occupational exposure limits in the nanogram per cubic metre range, dedicated equipment and validated deactivation. The free thiol oxidises readily to the disulfide dimer, so it is typically stored cold, under inert gas and protected from light. Watch the epimer at the N-methyl-L-alanine side chain and other maytansinoid-related impurities, as they carry through into the conjugate.

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.