iBio, a developer of next-generation biopharmaceuticals and pioneer of the sustainable FastPharming Manufacturing System, has signed a definitive worldwide exclusive license agreement with RubrYc Therapeutics for RTX-003, an immunotherapy candidate targeting regulatory T cells (Tregs). The partnership also includes an option agreement for iBio to license additional antibodies built using RubrYc’s artificial intelligence (AI)-based antibody discovery platform.
 
“We are pleased to add another promising candidate to our growing oncology R&D pipeline, and especially one with such a compelling mechanism of action,” said Tom Isett, chairman and CEO, iBio. “Designing an antibody that effectively binds CD25 without blocking the IL-2 signaling pathway is a widely recognized challenge, so the successful preclinical development of RTX-003 provides validation of RubrYc’s capabilities. Moving forward, we aim to replicate this discovery and development model by combining access to the RubrYc Discovery Platform with iBio’s proprietary Glycaneering and FastPharming Technologies to bring multiple new candidates to the clinic in a timely and cost-efficient manner.”
 
CD25 has emerged as a promising target in immuno-oncology because it is expressed by immunosuppressive Tregs and overexpressed in certain tumor cells. Preclinical data on RTX-003 has shown that it selectively binds and depletes Tregs in the tumor microenvironment without compromising immunostimulatory interleukin 2 (IL2) signaling to other T cells, thereby generating strong anti-tumor responses. These robust anti-tumor effects were observed using RTX-003 as a monotherapy, as well as in combination with checkpoint inhibitors.
 
The positive RTX-003 preclinical data are consistent with results from another non-IL2 blocking anti-CD25 antibody, one that is now in a Phase I clinical trial. Given the validation for this mechanism of action, iBio plans to use its development and manufacturing capabilities to advance RTX-003 to the clinic as IBIO-101, which is a version of RTX-003 produced in plants using the FastPharming System. Initiation of IND-enabling studies is expected by mid-2022.
 
As part of the agreements, iBio made an upfront $5 million payment to RubrYc, with an additional $2.5 million commitment for December 2021. In return, the company will receive the RTX-003 commercialization rights, options for additional molecules developed using RubrYc’s predictive algorithms, and an equity stake. RubrYc is eligible to receive certain pre-specified payments upon achievement of development milestones for IBIO-101, as well as royalties on net sales of that molecule and other licensed antibodies.
 
Isaac J. Bright, CEO, RubrYc, said, “This partnership creates tremendous synergy with three platform technologies that together may accelerate the rapid discovery and development of next-generation immunotherapies. We look forward to our exciting new collaboration with iBio.”