On July 17, 2025 I-Mab (NASDAQ: IMAB) (the Company), a U.S.-based, global biotech company, focused on the development of precision immuno-oncology agents for the treatment of cancer, reported that it entered into a definitive agreement to acquire 100% ownership of Bridge Health Biotech Co., Ltd. (Bridge Health) (Press release, I-Mab Biopharma, JUL 17, 2025, View Source [SID1234654422]). The transaction provides I-Mab with the rights to bispecific and multi-specific applications (including bispecific and multi-specific antibodies and antibody drug conjugates (ADCs)), based on the Claudin 18.2 (CLDN18.2) parental antibody used in the Company’s CLDN18.2 x 4-1BB bispecific antibody, givastomig.
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"Advancing givastomig is I-Mab’s top priority. The strategic acquisition of Bridge Health emphasizes I-Mab’s focus on enhancing the value of givastomig. With this transaction, I-Mab has further enriched the potential value of givastomig by strengthening upstream intellectual property rights, reducing future milestone payments, and unencumbering givastomig of future royalties," said Sean Fu, PhD, MBA, Chief Executive Officer of I-Mab. "Positive Phase 1b dose escalation data recently presented at ESMO (Free ESMO Whitepaper) GI 2025 has enhanced our confidence that givastomig has the potential to be a best-in-class CLDN18.2-directed therapy for gastric cancers and beyond. Continued clinical trial momentum has enabled faster than expected enrollment in the Phase 1b dose expansion cohorts, and we now expect to provide a topline readout in Q1 of 2026."
The CLDN18.2 parental antibody utilized in givastomig has been observed to show a higher affinity to human CLDN18.2 than other antibodies, including antibodies used in approved CLDN18.2-directed therapies. Additionally, the CLDN18.2 parental antibody has been observed to exhibit stronger binding affinity to cell lines expressing high, medium and even low levels of CLDN18.2. These characteristics are believed to be core to the differentiation of givastomig as a potential best-in-class, bispecific antibody designed to treat Claudin 18.2-positive cancers.
Givastomig is in development for the treatment of first line metastatic gastric cancers, with potential to expand into other solid tumors. Recently presented positive data from a Phase 1b dose escalation immunochemotherapy combination study showed an 83% objective response rate (ORR) in the doses selected for dose expansion cohorts, with favorable overall tolerability. I-Mab expects to present topline results from the Phase 1b dose expansion combination study in Q1 of 2026.
Transaction Terms
Under the terms of the agreement, I-Mab will pay Bridge Health shareholders an upfront payment of $1.8 million and non-contingent payments of $1.2 million through 2027. In addition, Bridge Health shareholders may receive future milestone payments of up to $3.875 million, subject to the achievement of certain development and regulatory milestones. The transaction is expected to close in Q3 of 2025.
Sidley Austin LLP served as legal advisor to I-Mab in connection with the transaction.
About Givastomig
Givastomig (TJ033721 / ABL111) is a bispecific antibody targeting Claudin 18.2 (CLDN18.2)-positive tumor cells. It conditionally activates T cells through the 4-1BB signaling pathway in the tumor microenvironment where CLDN18.2 is expressed. Givastomig is being developed for first line (1L) metastatic gastric cancers, with further potential in other solid tumors. In Phase 1 trials, givastomig has shown promising anti-tumor activity attributable to a potential synergistic effect of proximal interaction between CLDN18.2 on tumor cells and 4-1BB on T cells in the tumor microenvironment, while minimizing toxicities commonly seen with other 4-1BB agents.
An ongoing Phase 1b study is evaluating givastomig for the treatment of gastric cancer in the 1L setting in combination with standard of care, nivolumab (an anti-PD-1 checkpoint inhibitor) plus chemotherapy, in dose escalation and dose expansion cohorts. Data from the dose escalation cohorts (n=17), presented at the European Society for Medical Oncology Gastrointestinal Cancers Congress (ESMO GI 2025) showed an 83% objective response rate (ORR) at doses selected for dose expansion, with responses in patients with low PD-L1 and CLDN18.2 expression. Responses were rapid, durable and deepened over time, with a favorable overall safety profile. Enrollment in the first dose expansion cohort (n=20) finished ahead of schedule and enrollment in the second dose expansion cohort (n=20) is nearly complete. Topline data are expected in Q1 of 2026.
Givastomig is being jointly developed through a global partnership with ABL Bio, in which I-Mab is the lead party and shares worldwide rights equally with ABL Bio, excluding Greater China and South Korea.