China-based Antengene Corporation Limited (HKEX: 6996) has licensed its preclinical CDH6 × CD3 bispecific T cell engager ATG-106 to K2 Therapeutics, a vehicle established by Boston-based venture firm MPM BioImpact, for up to USD 980.5 million per asset across two separate agreements. The deal marks Antengene's second out-licensing of its AnTenGager masked TCE platform in fewer than four months following a deal signed with UCB in March 2026.
Antengene will receive approximately USD 20 million in upfront and near-term consideration for ATG-106 — comprising cash and a minority equity stake in K2's newly incorporated asset subsidiary — plus up to USD 960.5 million in developmental, regulatory, and sales milestones, and tiered royalties on net sales. A separate option agreement grants K2 the right to license an undisclosed preclinical bispecific TCE candidate on identical economic terms: approximately USD 20 million in consideration upon exercise and up to USD 960.5 million in milestones. Antengene retains all rights in Greater China under both agreements.
Deal context
ATG-106 is described by Antengene as a preclinical CDH6 × CD3 bispecific T cell engager targeting solid tumors, primarily ovarian cancer and renal cell carcinoma, where CDH6 is overexpressed. It is built on Antengene's AnTenGager platform, which the company describes as incorporating steric hindrance-based masking of the CD3-binding arm — designed to activate T cells only in the presence of target antigen, with the stated aim of reducing cytokine release syndrome and T cell exhaustion relative to first-generation TCEs. The company presented ATG-106 preclinical data including non-human primate safety findings at AACR 2026. An IND submission is planned for Q2 2027.
The deal structure carries several atypical features. The USD 20 million upfront consideration is below the USD 80 million upfront and near-term payments disclosed in Antengene's March 2026 UCB agreement for ATG-201, a CD19/CD3-targeted TCE. The equity component partially substitutes for cash, aligning Antengene's interests with K2's development success but reducing immediate liquidity. The milestone-to-upfront ratio of approximately 48:1 indicates a heavily back-loaded structure consistent with the asset's early preclinical stage.