Third Arc Bio and Adagene Forge $840M Deal for Innovative T-Cell Engager Technology

In a significant move that promises to advance the development of precision cancer therapies, Third Arc Bio has entered into a licensing agreement with Adagene for its cutting-edge Safebody technology. The deal, announced on November 13, 2025, could be worth up to $840 million, highlighting the pharmaceutical industry's growing interest in masked antibody platforms for targeted cancer treatment.

Strategic Partnership for Next-Generation T-Cell Engagers

Third Arc Bio, a Pennsylvania-based biotech company, will leverage Adagene's precision antibody masking platform to create new CD3 T-cell engagers targeting tumor-associated antigens. The collaboration aims to enhance the safety and efficacy of cancer immunotherapies by utilizing Adagene's Safebody technology, which is designed to activate antigens specifically within the tumor microenvironment.

Under the terms of the agreement, Third Arc Bio will pay an upfront fee of $5 million to Adagene. The deal includes potential development and commercial milestones totaling $840 million, along with royalties on future sales. Third Arc Bio will gain global rights to research, develop, and market two candidates resulting from this partnership, while Adagene retains a no-cost option for development and commercialization in certain Asian markets.

Expanding the Therapeutic Index in Cancer Treatment

Peter Luo, Ph.D., CEO of Adagene, emphasized the potential of the Safebody platform to improve the therapeutic index of cancer treatments. By masking antibodies until they reach the tumor site, the technology aims to reduce off-target effects and enhance overall safety profiles of T-cell engagers.

Peter Lebowitz, M.D., Ph.D., CEO of Third Arc Bio, expressed enthusiasm about the collaboration, stating, "Our agreement with Adagene will allow Third Arc Bio to advance highly innovative molecules with a superior therapeutic index and help build on our growing portfolio of novel CD3- and CD28-targeting T-cell engagers."

Advancements in Clinical Pipeline

The partnership comes at a time when both companies are making strides in their respective clinical programs. Third Arc Bio's lead program, ARC101, is currently in phase 1 trials for solid tumors expressing CLDN6. Meanwhile, Adagene's lead clinical program, ADG126 (muzastotug), a masked anti-CTLA-4 candidate, is undergoing phase 1b/2 and phase 2 clinical studies in combination with anti-PD-1 therapy for microsatellite stable colorectal cancer.

This latest deal builds on Adagene's growing reputation in the field of masked antibody technologies. The company has previously partnered with pharmaceutical giant Sanofi, which recently reinforced its commitment by investing an additional $25 million in Adagene and expanding their collaboration.

As the pharmaceutical industry continues to seek innovative approaches to cancer treatment, partnerships like the one between Third Arc Bio and Adagene underscore the potential of precision antibody technologies to reshape the landscape of immunotherapy and offer new hope for cancer patients.