Antengene Corporation, a global commercial-stage biotechnology company, has entered into a licensing agreement with UCB granting the latter worldwide exclusive rights to develop, manufacture and commercialise ATG-201, a bispecific T-cell engager antibody designed to treat B-cell related autoimmune diseases.

Under the agreement, UCB will also gain access to Antengene’s associated manufacturing technology for ATG-201. In return, Antengene will receive USD 80 million in upfront and near-term milestone payments and will be eligible for more than USD 1.1 billion in additional development, regulatory and commercial milestones, along with tiered royalties on future global sales.

ATG-201 is a CD19/CD3 bispecific T-cell engager developed using Antengene’s proprietary AnTenGager platform. The therapy is designed to selectively eliminate CD19-expressing B cells, which are known to play a critical role in autoimmune disorders and certain blood cancers. By engaging both T cells and B cells simultaneously, the therapy leverages the body’s immune system to precisely target disease-causing cells.

The molecule incorporates bivalent CD19 binding along with steric hindrance masking technology and a proprietary CD3 sequence, a design intended to enhance targeted B-cell depletion while potentially reducing the risk of Cytokine Release Syndrome (CRS), a common complication associated with immune-based therapies.

Antengene plans to submit clinical trial applications for ATG-201 in China and Australia during the first quarter of 2026. The company will conduct first-in-human Phase I trials in these regions before transferring further global clinical development and commercialisation responsibilities to UCB.

Dr Jay Mei, Founder, Chairman and Chief Executive Officer of Antengene, said the partnership combines Antengene’s discovery platform and clinical development capabilities with UCB’s strong expertise in immunology to accelerate global development of ATG-201. He added that the collaboration highlights the potential of the company’s AnTenGager platform to develop next-generation T-cell engagers across multiple therapeutic areas.

Antengene’s AnTenGager platform features a differentiated mechanism in which the CD3 binding arm of the T-cell engager is sterically masked until it encounters the target antigen. This design is intended to enable potent therapeutic activity while improving tolerability.

UCB’s Chief Scientific Officer, Alistair Henry, noted that the collaboration strengthens the company’s strategy to expand its leadership in immunology and adds new capabilities in the growing field of bispecific T-cell engagers. He said the partnership aligns with UCB’s broader innovation strategy and complements its existing portfolio of monoclonal antibodies and advanced biologics.

According to Antengene’s research leadership, the platform’s steric hindrance-based masking and proprietary CD3 binding technology not only help reduce the risk of cytokine release syndrome but may also limit T-cell exhaustion, improving therapeutic durability.

Following this agreement, Antengene’s AnTenGager platform will continue advancing a pipeline of nine disclosed candidates targeting autoimmune diseases, solid tumours and haematological malignancies.