Hong Kong-headquartered Antengene Corporation and Brussels-based UCB (Euronext Brussels) announced a global license agreement granting UCB worldwide exclusive rights to develop, manufacture, and commercialize ATG-201, a CD19/CD3 bispecific T-cell engager antibody targeting B cell-related autoimmune diseases. For UCB, the deal represents a return to B cell-targeting strategies in the immunology space.
UCB gains access to the manufacturing technology related to ATG-201, while Antengene will lead on IND filings for the molecule and initiation of first-in-human Phase I studies in China and Australia before transferring further clinical development to UCB.
Antengene will receive USD 60 million upfront and USD 20 million in near-term milestone payments, totaling USD 80 million in upfront and near-term consideration. The company is eligible for over USD 1.1 billion in success-based development, regulatory, and sales milestones, along with tiered royalties on future net sales. The deal is structured as a full global out-license, with Antengene retaining no long-term territorial commercialization rights.
Deal context
ATG-201 is a bispecific antibody built on Antengene’s proprietary AnTenGager platform, which uses a “2+1” format — two CD19 binding arms and one CD3 binding arm — combined with steric hindrance masking technology and a proprietary fast-on-fast-off CD3 binder. The molecule is designed to redirect T cells to eliminate CD19-expressing B cells while reducing the risk of cytokine release syndrome. Antengene plans to submit clinical trial applications for ATG-201 in China and Australia in Q1 2026. The asset is pre-Phase I, with no clinical trial registry entries publicly available at the time of announcement.
For UCB, the deal adds a B cell autoimmune therapy modality to an immunology pipeline historically built on monoclonal antibodies and other biologics. UCB previously pursued CD22-targeted B cell depletion through an epratuzumab collaboration with Immunomedics, structured in 2009 with approximately USD 38 million upfront and later restructured in 2011; that program was ultimately discontinued. The ATG-201 agreement represents a return to B cell-targeting strategies, this time via a T-cell engager format. No prior deals between Antengene and UCB were identified; this is the first transaction between the two companies.
For Antengene, the transaction represents a shift from its historical pattern of in-licensing Western assets for Asia-Pacific development — such as its selinexor license from Karyopharm Therapeutics — to out-licensing a proprietary, platform-derived candidate to a global pharma company. Nine additional disclosed products remain in the AnTenGager pipeline.
The Antengene transaction comes amid rising industry investment in T-cell engager therapies targeting B-cell biology in autoimmune diseases. In January 2025, Merck acquired global ex-China rights to Curon Biopharmaceutical’s CD19×CD3 bispecific antibody CN201 in a deal worth up to USD 1.3 billion, including USD 700 million upfront. Candid Therapeutics is another TCE specialist focused on autoimmune programs, and recently merged with Rallybio gaining USD 505 million in new financing, with programs targeting BCMA, CD20, and CD19/CD20 combinations.
The modality also has precedent in oncology through Amgen’s CD19/CD3 bispecific blinatumomab (Blincyto), which is currently being evaluated in a Phase II autoimmune disease study (NCT06570798) in systemic lupus erythematosus and rheumatoid arthritis. Meanwhile, CD19 CAR-T therapies for autoimmune disease include Kyverna Therapeutics’ KYV-101, currently Phase 2 for lupus nephritis.
The UCB license agreement positions the company within this competitive set, though ATG-201’s differentiated platform design — incorporating conditional T-cell activation via steric masking — may address tolerability concerns that have limited earlier CD19/CD3 bispecific T-cell engager approaches. ATG-201 remains at an early development stage, and clinical data will be required to confirm whether the platform’s design translates into a differentiated safety and efficacy profile relative to both CAR-T and other TCE modalities targeting autoimmune diseases indications.