The ADC Capacity Race: Three Expansion Playbooks from WuXi XDC, Samsung Biologics and Lonza

Small-molecule players extend into linker-payloads, biologics players extend from mAbs into conjugation, and large CDMOs fill gaps in drug product and fill-finish — different starting points, the same destination: integrated XDC. China's H1 2026 license-out value neared USD 100B.

The ADC (antibody-drug conjugate) boom is moving from R&D to the production line. As ADCs evolve into XDCs — where the classic "antibody + small-molecule payload" no longer covers all needs — capabilities for oligonucleotides, peptides, protein degraders and novel payloads have become the focus of CDMO competition.

Three distinct expansion logics are visible: small-molecule specialists extending into linker-payloads and conjugation; biologics players extending from mAbs into conjugation; and multi-platform CDMOs filling gaps in payload-linkers, drug product and fill-finish.

WuXi XDC represents the vertical-integration route. In 2025 it posted revenue of RMB 5.94B (+46.7%) with a USD 1.49B backlog. Its planned Jiangyin payload-linker facility will have capacity equal to five times the current Wuxi base; the TOT Biopharma (Dongyao) acquisition added mAb, drug substance and drug product capability; the Hefei site adds peptide and oligonucleotide synthesis; and together with the Singapore site, a "China + Singapore" dual-supply system has taken shape.

Samsung Biologics, a large-scale mAb specialist, has stood up a dedicated ADC facility — with up to 500 L conjugation reactors and containment systems targeting occupational exposure limits below 1 ng/m³ for HPAPI handling. Its ADC drug product line is slated for completion in Q1 2027 to build end-to-end ADC capability.

Lonza runs arguably the most complete single-organization chain: antibody, linker, payload, conjugation and drug product — and in 2026 integrated the Synaffix platform, adding dual-payload ADC technology. A "networked one-stop" model is also emerging, where one platform coordinates project management across specialized suppliers. For China's CXDMOs, H1 2026 license-out deals reached USD 99.7–110B, and China now hosts 1,728 clinical trials versus 1,520 in the US — China has become a co-equal center of ADC innovation.