CytomX Therapeutics, Inc. (Nasdaq:CTMX), announced on 5/22/18 that the U.S. Food and Drug Administration has cleared its Investigational New Drug (IND) application for CX-2029, a first-in-class CD71-directed Probody drug conjugate being co-developed by CytomX and its partner AbbVie. CD71, also known as the transferrin receptor 1, is a highly expressed protein present in a number of solid and hematologic cancers that possess attractive molecular properties for the efficient delivery of cytotoxic payloads to tumor cells. The achievement of this milestone triggers a $25 million payment to CytomX from AbbVie.
“CD71 has long been considered a high potential but challenging target for antibody drug conjugates given its high expression in tumors but ubiquitous expression in normal tissues. However, we see CD71 is an attractive candidate for a Probody drug conjugate approach, since our technology can potentially localize treatment directly to tumor tissue,” said Sean McCarthy, D.Phil., president and chief executive officer of CytomX Therapeutics. “With CX-2029 now clear to advance into Phase 1, CytomX and our partners now have four clinical-stage Probody programs with anticipated initial data readouts later this year from our two wholly-owned programs, CX-072 and CX-2009. It is also noteworthy that this milestone comes just two years following the signing of our agreements with AbbVie, reflecting the efficiency of this collaboration.”
AbbVie and CytomX are co-developing CX-2029, a Probody drug conjugate against CD71, with CytomX leading pre-clinical and early clinical development. AbbVie will lead later development and commercialization, with global late-stage development costs shared between the two companies. CytomX 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 U.S. and tiered double-digit royalties on net product sales outside of the U.S. CytomX retains an option to co-promote in the U.S.
AbbVie also received exclusive worldwide rights to develop and commercialize 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.
Cytomx's pipeline includes cancer immunotherapies against clinically-validated potential targets, such as CX-072, a PD-L1-targeting Probody therapeutic wholly-owned by CytomX, BMS-986249, a CTLA-4-targeting Probody therapeutic partnered with Bristol Myers Squibb, CX-188, a PD-1-targeting Probody therapeutic wholly-owned by CytomX, and first-in-class Probody drug conjugates against high potential targets, such as CX-2009, a CD166-targeting Probody drug conjugate wholly-owned by CytomX and CX-2029, a CD71-targeting Probody drug conjugate partnered with AbbVie, which are considered to be inaccessible to conventional antibody drug conjugates due to their presence on healthy tissue. In addition to its wholly owned programs, CytomX has strategic collaborations with AbbVie, Amgen, Bristol-Myers Squibb Company, and ImmunoGen, Inc.