ProBio Licenses Oncology Antibody to AbTis for Site-Specific ADC

ProBio, a contract research, development and manufacturing organization, has granted AbTis Co., Ltd. exclusive global rights to a discovery-stage therapeutic antibody directed at an oncology target.¹ AbTis, a South Korean company and subsidiary of Dong-A ST, plans to use the antibody to expand a pipeline of bispecific antibody-drug conjugates (ADCs) built on its site-specific conjugation platform.¹

“This agreement demonstrates the value of ProBio's strategy to not only support our partners' programs, but also generate differentiated assets that can advance into innovative therapeutic development,” said Allen Guo, CEO, ProBio. “By combining ProBio's biologics discovery capabilities with AbTis' site-specific ADC technology, we have the opportunity to accelerate the development of a promising oncology asset and create additional value for patients and our partners.”¹

What are the terms of the ProBio-AbTis licensing agreement?

AbTis holds the right to develop and commercialize the antibody worldwide.¹ ProBio will receive an upfront payment, with potential developmental and commercial milestone payments and royalties on future sales.¹

The announcement did not disclose payment amounts, name the antibody's target or include preclinical or clinical data on the asset.¹

How does AbTis' AbClick platform conjugate antibodies?

AbTis describes its AbClick platform as enabling controlled, site-specific conjugation, an approach intended to improve ADC consistency compared with conventional nonspecific methods.¹ Peer-reviewed work from AbTis scientists describes one version of the chemistry.

A peptide that binds the antibody's constant region carries a reactive thioester positioned next to a single lysine residue on trastuzumab, allowing that site to be modified selectively.² A subsequent click reaction attached the drug, producing a conjugate with two drugs per antibody that showed activity in cell and animal models.²

That study used an existing antibody as the test case, so it does not speak to the licensed asset.

“This licensing agreement marks an important step in advancing this promising antibody asset toward ADC development,” said Dr. Hyungsuk Choi, CEO, AbTis. “We look forward to leveraging the AbClick platform and working with ProBio to accelerate development of this program.”¹

Why does conjugation consistency matter in ADC development?

A 2025 review notes that conjugation site, drug-to-antibody ratio control and linker stability influence pharmacokinetics, efficacy, and safety.³ The review reports that more than a dozen ADCs have received FDA approval and that more than 200 are in active clinical trials.

It adds that site-specific methods have improved homogeneity and stability, although large-scale manufacturing and regulatory harmonization remain challenges.³ For development and manufacturing organizations, that places the conjugation step within process development and analytical control, not only discovery.

Who is AbTis, and why does the deal matter to manufacturing partners?

AbTis was founded in 2016 and became a Dong-A ST subsidiary in December 2023, when the parent company described AbClick as a third-generation linker platform with medium- to long-term goals of expanding into ADC contract development and manufacturing.⁴ AbTis had previously signed an ADC technology agreement with Lonza.⁴

ProBio offers biotechnology and pharmaceutical partners an integrated path from discovery through development and manufacturing.¹ The licensing agreement links its discovery work to a partner with its own conjugation technology, although the announcement does not say whether ProBio would manufacture the resulting ADC.¹

What are the limitations and next steps?

The asset is at the discovery stage, and no target, binding, efficacy or safety data were provided. The peer-reviewed data cited here involve a single marketed antibody and a two-drug conjugate and do not address bispecific formats.²

Whether the approach delivers consistency and manufacturability at commercial scale will depend on process development and regulatory review of the conjugated product, topics the companies did not address.³ Development timelines, milestone triggers and the antibody's target remain unstated.¹

Sources

1. ProBio enters exclusive global licensing agreement with AbTis to develop next-generation ADC asset. News release. ProBio Inc. PR Newswire; November 10, 2026. Accessed November 11, 2026.
2. Lee T, Kim JH, Kwon SJ, et al. Site-selective antibody-drug conjugation by a proximity-driven S to N acyl transfer reaction on a therapeutic antibody. J Med Chem. 2022;65(7):5751-5759. doi:10.1021/acs.jmedchem.2c00084
3. Alradwan IA, Alnefaie MK, AL Fayez N, et al. Strategic and chemical advances in antibody-drug conjugates. Pharmaceutics. 2025;17(9):1164. doi:10.3390/pharmaceutics17091164
4. Dong-A ST secures ADC platform with AbTis acquisition. The Asia Business Daily. December 20, 2023. Accessed November 11, 2026.