AbbVie, a global, research-based biopharmaceutical company, and CytomX Therapeutics, Inc, an oncology-focused biopharmaceutical company, announced that they have entered into a collaboration to co-develop and co-commercialise Probody Drug Conjugates against CD71, also known as transferrin receptor 1 (TfR1). CD71 is highly expressed in a number of solid and hematologic cancers and has attractive molecular properties for efficient delivery of cytotoxic payloads to tumour cells. Probody therapeutics are designed to take advantage of unique conditions in the tumour microenvironment to enhance the tumour-targeting features of an antibody and reduce drug activity in healthy tissues.

"We believe that the Probody platform provides a differentiated opportunity to combine with our strength in antibody drug conjugates," said Steve Davidsen, Ph.D., vice president, oncology drug discovery, AbbVie. "We are encouraged by the promising preclinical data that CytomX has generated for their Probody drug conjugate programmes to-date and look forward to working closely with their team. This collaboration will enable us to expand our innovative pipeline in antibody drug conjugates and leverage our strength in that area to previously unexplored targets."

"This collaboration is another important step toward achieving CytomX's vision of transforming lives with safer, more effective therapies and allows us to further advance our broad pipeline of Probody therapeutics," stated Sean McCarthy, D.Phil., president and chief executive officer at CytomX. "AbbVie has demonstrated leadership in developing antibody drug conjugates and we look forward to collaborating with their team to realize the full potential of our CD71 Probody drug conjugate programme and additional oncology targets."

Probody therapeutics are designed to remain inactive until they are activated by proteases in the tumour microenvironment. As a result, Probody therapeutics bind selectively to tumours and avoid binding to healthy tissue, to minimise toxicity and potentially create safer, more effective therapies. CytomX has generated preclinical data that demonstrates that Probody drug conjugates can safely and effectively target tumor antigens, such as CD71, that are not addressable by conventional antibody-drug conjugates.

Under the terms of the agreement, CytomX and AbbVie will co-develop a Probody drug conjugate against CD71, with CytomX leading pre-clinical and early clinical development. AbbVie will lead later development and commercialisation, with global late-stage development costs shared between the two companies. CytomX will receive an upfront payment of $30 million and is eligible to receive up to $470 million in development, regulatory and commercial milestones, pending the achievement of pre-determined outcomes. AbbVie will lead global commercial activities with CytomX eligible to receive a profit share in the US and tiered double-digit royalties on net product sales outside of the US CytomX retains an option to co-promote in the US.

AbbVie also receives exclusive worldwide rights to develop and commercialise Probody drug conjugates against up to two additional, undisclosed targets. Should AbbVie ultimately pursue these targets, CytomX is eligible to receive additional milestone and royalty payments per target on any resulting products.