I-Mab has solidified its pivot to givastomig by buying out the owner of an antibody used in the therapy.
Maryland-based I-Mab kicked off the year by announcing that it was pausing work on the Sanofi-partnered anti-CD73 antibody uliledlimab and was instead focusing on the CLDN18.2x4-1BB bispecific givastomig. That move involved laying off around 27% of the biotech’s employees.
Now, I-Mab is strengthening its rights to givastomig by buying Bridge Health, which owns the CLDN18.2 parental antibody used in the drug. Bridge Health’s antibody is considered to be the secret sauce to givastomig’s potential success, with I-Mab pointing out in the July 17 release that 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,” I-Mab explained in the release.
To secure the antibody, I-Mab is paying $1.8 million upfront to buy Bridge Health, to be followed by noncontingent quarterly payments totaling $1.2 million.
Bridge Health’s shareholders could also be in line for up to $3.9 million in potential development and regulatory milestones under the agreement.
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.
I-Mab is pitching the bispecific as a candidate that can work in people with low levels of CLDN18.2 expression, improve upon the efficacy offered by Astellas’ Vyloy and be more tolerable than antibody-drug conjugates. So far, the drug has been tied to a 83% objective response rate in certain doses in a phase 1b trial in gastric cancers.
I-Mab CEO Sean Fu, Ph.D., said “faster than expected enrollment” in a phase 2 trial meant the company is now eyeing a top-line readout in the first quarter of 2026. There is also potential to expand the drug into other solid tumors.
“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,” Fu added in the release. “Positive phase 1b dose escalation data recently presented at ESMO 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.”