Astellas in oncology antibody drug pact with Ambrx

Astellas Pharma Inc.today said it had entered into a collaboration with protein pharmaceutical developer Ambrx Inc for the discovery and development of novel antibody drug conjugates (ADCs).

Ambrx is based on a fundamental advance in protein biosynthesis that enables the company to genetically engineer proteins with new amino acid building blocks beyond the existing 20 natural amino acids, enabling the biosynthesis of proteins with new physical, chemical and pharmacological properties.

Antibody drug conjugates allow for the targeted delivery of drugs to the target tissue. Ambrx creates optimised ADCs using its site-specific conjugation technology along with proprietary linkers and payloads. In the preclinical setting, Ambrx ADCs have demonstrated high potency and a wider therapeutic index than ADCs created using conventional non-specific conjugation.

Ambrx will receive an upfront payment of $15 million from Astellas, as well as up to $285 million in potential near and long-term research, development, regulatory and sales-based milestones for an undisclosed number of targets for ADCs in oncology.

A portion of these milestones, as well as royalties on any net sales, will be contingent on eventual successful commercialization of products developed as a result of this partnership. Astellas will receive worldwide rights to develop and commercialize ADCs for oncology. Additional terms of the collaboration are not disclosed at this time.

''Agensys, Inc., an affiliate of Astellas which specialises in therapeutic antibody research and development in cancer, has significant experience with ADCs as oncology therapeutics and is looking to further expand its capabilities in this area.  Ambrx offers a novel approach to allow creation of site-specific and highly stable conjugations that have the potential to further optimize drug delivery to tumor cells.'' said David Stover, Ph.D., Senior Vice President and Agensys Site Head.

Added Lawson Macartney, chief executive officer of Ambrx, "We recognise Astellas as a leader in the development of innovative therapeutics for oncology and are proud to initiate this collaboration. We look forward to developing these therapeutics while also advancing our broad pipeline of partnered and wholly owned therapeutic candidates with best-in-class conjugation.''