US based Biocytogen Pharmaceuticals entered a strategic collaboration with Japan headquartered LiberoThera to co-develop fully human GPCR antibodies using Biocytogen’s advanced antibody discovery platform based on fully human antibody RenMab mice combined with LiberoThera’s outstanding membrane antigen preparation technology. In around a year since the collaboration was established, the two parties have reportedly screened out a number of fully human therapeutic antibody clones with excellent anti-tumor activity in vitro and in vivo against the first mutually selected GPCR target, CCR8, which has the potential to become a best-in-class product. These antibody clones exhibit high affinity binding to human CCR8 with species cross-reactivity and good manufacturability. Mechanistically, these clones can deplete Tregs from the tumor micro-environment through enhanced ADCC activity, and can also inhibit the activities of Tregs in the tumor micro-environment by inhibiting CCR8 signaling mediated by its ligand CCL1, thereby enhancing the anti-tumor immune response. In the future, the collaborations between two parties will also be extended to other GPCR targets.
GPCRs are seven-transmembrane proteins with short extracellular domains and high homology among them which make it difficult to find antibodies against them with high specificity and desired functions. However, both the success rate and the speed of GPCR antibody discovery have greatly increased by combining Biocytogen’s target knocked-out fully human antibody mice RenMab KO, various immunization and antibody discovery technologies, high-throughput in vitro and in vivo screening platform and LiberoThera’s deep understanding of GPCR target structures plus membrane antigen preparation technologies.
“We are very pleased that with the joint efforts of us and LiberoThera, the drug development of CCR8, a potential target for tumor immunotherapy, is progressing smoothly.” said Dr. Yuelei Shen, Founder, Chairman and CEO of Biocytogen. “This undoubtedly validates that LiberoThera’s advanced antigen preparation technology synergizes with our RenMice KO platform to generate diverse fully human antibodies. Furthermore, our high-throughput in vivo and in vitro screening capabilities ensured that antibodies against GPCRs can be efficiently obtained. We look forward to advancing our CCR8 antibodies into the clinic soon and we also look forward to continue working with LiberoThera to tackle more GPCR targets.”
“Many GPCRs are important drug targets for a variety of indications. However, due to the special structure of such targets, the development of antibody drugs against them has always been challenging,” said Dr. Toru Kanke, CEO of LiberoThera. “The structural GPCR antigens prepared with LiberoThera’s proprietary cell-free membrane synthesis technologies together with non-natural amino acid incorporation methods can provide a solution for generating quality antibodies against the challenging targets. Biocytogen’s streamlined fully human antibody development platform greatly accelerates the translation of GPCR research. We are very happy to see the rapid progress and discovery of the best-in-class therapeutic antibodies against CCR8 under the collaboration of both parties. We also look forward to the collaborations in the future with Biocytogen to work on more GPCR targets so that to benefit more patients around the world.”