Antengene Corporation and UCB have entered a licensing deal worth up to $1.18 billion, aiming to develop ATG-201, an experimental T-cell engager therapy targeting B cell-driven autoimmune diseases.

“We are delighted to partner with UCB, combining our innovative discovery platform and clinical execution capabilities with their deep expertise and experience in immunology to accelerate ATG-201’s development efficiently and on a global scale,” said Dr. Jay Mei, founder, chairman, and CEO of Antengene. “ATG-201, specifically designed for autoimmune diseases, incorporates bivalent CD19 binding, steric hindrance-based masking technology and proprietary CD3 sequence, a strategy designed to enable effective B cell depletion and reduce the risk of cytokine release syndrome (CRS). This collaboration further underscores AnTenGagerTM platform’s unique capability in developing next generation novel TCEs with broad applicability in different therapeutic areas.”

ATG-201 is a bispecific T-cell engager (TCE) that targets CD19, a protein expressed on B cells. It is designed to direct the body's own T cells to eliminate B cells implicated in autoimmune disorders and certain blood cancers.¹

The therapy incorporates steric hindrance masking technology, which is intended to improve tolerability by reducing the risk of cytokine release syndrome (CRS), a potentially serious immune reaction associated with T-cell engager therapies, and limiting T cell exhaustion.¹

Antengene plans to submit clinical trial applications in China and Australia in the first quarter of 2026 and is expected to complete the first-in-human Phase I studies in both countries before transferring further development to UCB.¹

What are details of the agreement?

Per the terms of the lisencing agreement, UCB received its worldwide exclusive license to develop, manufacture, and commercialize ATG-201, along with access to Antengene's associated manufacturing technology.

Antengene is expected to receive an upfront and near-term payment of $80 million, comprised of an initial $60 million payment and up to $20 million in additional near-term milestones with eligibility for more than $1.1 billion in future development and commercial milestones, plus tiered royalties on net sales.¹

Why are both companies pursuing this deal?

For Antengene, the partnership provides global reach and immunology expertise to accelerate ATG-201's development, while for UCB, the deal expands its capabilities beyond monoclonal antibodies into the emerging field of bispecific T-cell engagers.¹

Alistair Henry, chief scientific officer at UCB, described ATG-201 as a potentially disruptive therapeutic modality offering a targeted, durable, and scalable treatment option for immunological diseases. Dr. Jay Mei, founder, chairman, and CEO of Antengene, said the collaboration underscores the broader applicability of the company's AnTenGager platform across autoimmune diseases, solid tumors, and blood cancers.¹

The agreement also builds on presented preclinical data for ATG-201 back at the 2025 American College of Rheumatology Annual Meeting in Chicago in October last year, where ATG-201 achieved complete and sustained B cell depletion in blood, bone marrow, and spleen in humanized mouse models following a single dose, while producing significantly lower cytokine release compared to benchmark T-cell engager therapies.²

The therapy also showed reduced T-cell exhaustion, a common limitation of first-generation T-cell engagers, pointing to a potentially more durable treatment effect. In non-human primates, a surrogate version of ATG-201 delivered deep B cell depletion with only a mild and transient increase in cytokine levels, supporting a favorable safety profile.²

Sources

1. Antengene and UCB Enter Global License Agreement for ATG-201, a CD19/CD3 Bispecific T-Cell Engager for Autoimmune Diseases Antegene March 4, 2026 https://www.antengene.com/newsinfo/463
2. Antengene Presents Latest Preclinical Data of ATG-201 (CD19 x CD3 TCE) at ACR 2025 Antegene October 27, 2025 https://www.antengene.com/newsinfo/450