Plant-based biopharma firm iBio licenses novel antibody targeting regulatory T cells

02-Sep-2021 - Last updated on 08-Sep-2021 at 08:17 GMT

Anti-CD25 antibodies have emerged as promising next-generation cancer therapeutics, says US plant-based manufacturer of therapeutics and vaccines, iBio, as it enters the field.

The company has signed a worldwide exclusive licensing agreement for the development and commercialization of RubrYc’s targeting monoclonal antibody, RTX-003, an immunotherapy candidate targeting regulatory T cells (Tregs).

This monoclonal antibody [mAb] was initially developed on a traditional mammalian cell manufacturing platform but iBio plans to optimize and manufacture RTX-003 and future antibody candidates using its plant-based FastPharming protein expression system, which it maintains allows for safe, sustainable, and scalable biologics production at industry-leading speeds.

IND-enabling studies for IBIO-101, the plant-made version of RTX-003, are anticipated within the next ten months, it revealed.

As part of the agreement, iBio made an upfront US$5m payment to RubrYc, with an additional US$2.5m commitment for December 2021. 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.

In addition:

iBio secures option to four new antibodies developed with RubrYc’s machine-learning predictive algorithms
iBio receives a 17.6% equity stake in RubrYc
iBio receives access to RubrYc’s artificial intelligence-based antibody discovery platform, allowing faster and more cost-efficient development of anti-cancer therapeutic candidates

‘Pivotal milestone’

The partnership with RubrYc is a pivotal milestone for iBio which could create value in multiple ways, says Tom Isett, CEO of iBio.

“We are thrilled to add another promising candidate to our expanding immuno-oncology R&D pipeline.”

CD25 is expressed by immunosuppressive Tregs and overexpressed in certain tumor cells, which allows cancer cells to hide from an immune response. The preclinical data have shown that targeting CD25 with RTX-003 removes that veil and generates a strong anti-tumor response when treated both as a monotherapy, and in combination with other immune checkpoint inhibitors, said the CEO.

“We have reviewed the preclinical data extensively and we are confident that RTX-003, now called IBIO-101, has the potential to become a next-generation cancer therapeutic given its unique ability to enhance tumor killing by the immune system through targeting CD25 receptors on Tregs without interfering with IL-2 signaling.

“We also received to option to license additional antibodies built using RubrYc’s artificial intelligence (A1)-based antibody discovery platform which, when combined with our Glycaneering and FastPharming technologies, will allow faster and more cost-efficient development of anti-cancer therapeutic candidates beyond IBIO-101,” he told BioPharma-Reporter.

Tregs therapy trend

Targeting harmful regulatory Tregs continues to gain attention in the growing field of immuno-oncology.

Last month, GentiBio raised a US$157m series A round to advance its Treg therapies. Gilead paid US$120m for Jounce's Treg therapy targeting CCR8 in 2020. And Roche spent US$81m with another US$677m in possible milestone payments to acquire Tusk Therapeutics for its Tregs immunotherapies targeting CD25 and CD38 in 2018.

“The success of others developing similar assets is encouraging for our team, and we expect that combining this incredibly promising approach with our unique benefits from plant-based manufacturing will only further bolster the promise of this program,” said Isett.

Advancing candidates into the clinic

iBio is in the midst of an exciting period of growth, said the CEO.

“Producing biologics in whole plants allows for improved speed, scalability, and sustainability over traditionally used mammalian cell culture production methods, and our innovative and seasoned leadership team is prepared to deliver these benefits to therapeutic development for immuno-oncology, as well as fibrotic and infectious diseases.

“We recently launched our oncology pipeline with three new antibody programs with plans to initiate IND-enabling studies for IBIO-101 by mid-2022.

“We also recently announced reports of successful preclinical immunization studies with IBIO-202, our next-gen COVID-19 vaccine candidate that aims to avoid the issues seen with spike-protein variants of the virus by targeting the more highly conserved nucleocapsid protein.

“Looking forward, we plan to continue advancing these novel plant-based candidates into the clinic with meaningful milestones to come within the next 12 months.”