Ifinatamab Deruxtecan (DS-7300): A Comprehensive Review of a Novel B7-H3-Directed Antibody-Drug Conjugate

I. Executive Summary

Ifinatamab deruxtecan (I-DXd), also known by its development codes DS-7300 and DS-7300a, is an investigational antibody-drug conjugate (ADC) emerging as a significant candidate in oncology therapeutics. It is meticulously engineered to target B7-H3 (CD276), a transmembrane protein frequently overexpressed across a wide array of solid tumors and often associated with poor prognosis.[1] The construct of Ifinatamab deruxtecan features a humanized anti-B7-H3 IgG1 monoclonal antibody (MABX-9001a) [4], a cleavable tetrapeptide-based linker, and Daiichi Sankyo’s proprietary topoisomerase I inhibitor payload, DXd.[1] This design leverages Daiichi Sankyo's DXd ADC technology, which has demonstrated success in other approved ADCs.

The development of Ifinatamab deruxtecan is a collaborative effort between Daiichi Sankyo, the originator and manufacturer, and Merck & Co., Inc. (known as MSD outside the U.S. and Canada), who are jointly responsible for its global clinical development and commercialization, with certain regional exceptions.[1] This partnership signifies a substantial commitment to the drug's potential, combining Daiichi Sankyo's specialized ADC platform expertise with Merck's extensive experience in global oncology drug development and marketing. Such collaborations are common in the biopharmaceutical industry to pool resources, share risks, and expedite the journey of promising assets to patients by leveraging complementary strengths in research, manufacturing, clinical execution, and market access.