Core Takeaways

In 2025, the number of ADCs in clinical development worldwide surpassed 200, spanning more than 50 targets.Yet the three traditional targets — HER2, TROP2, and Claudin18.2 — have fallen into homogeneous competition.With bispecific and dual-payload ADCs emerging, "no-man's-land" targets such as CDH17, B7-H3, PTK7, and CLDN6 are rising fast.

These new targets are becoming the new battleground for capital and pharma players.

ADC Competitive Landscape: Crowded Headline Targets Make Differentiation Inevitable

Three Traditional Targets: The Red Ocean

HER2, TROP2, and Claudin18.2 were once the "golden triangle" of ADCs but now face severe homogeneity.

HER2: More than 30 ADCs are in clinical development in China, spanning breast, gastric, and lung cancers.

DS-8201 (AstraZeneca/Daiichi Sankyo) has triggered a flood of follow-on programs; competition is white-hot.

TROP2: Gilead's Trodelvy dominates while at least 15 TROP2 ADCs are in development in China, with heavily overlapping indications (TNBC, HR+/HER2- breast cancer, NSCLC).

Claudin18.2: Hyped as a gastric-cancer-specific target but solid-tumor penetration remains unsolved; over 20 Claudin18.2 ADCs are in development in China.

Breakout Directions: From Monospecific to Bispecific, Single- to Dual-Payload

Faced with crowding, ADC technology is undergoing a paradigm shift.

Bispecific ADCs engage two antigens simultaneously with one bispecific antibody, increasing tumor specificity and reducing off-target toxicity.

Representative programs: ZW49 (Zymeworks) and M1231 (Merck).

Dual-payload ADCs carry two toxins with different mechanisms for synergy and reduced resistance risk.

A representative platform is Sutro Biopharma's dual-payload ADC platform.

Site-specific conjugation improves DAR uniformity and PK/PD properties.

Examples include Thiomer and Transgenic technologies.

Cleavable linkers release payloads specifically within the TME for "precision blasting."

Emerging Targets in Depth: Opportunity in the Blue Ocean

CDH17: A Rising Star in GI Cancers

CDH17 (cadherin-17) belongs to the cadherin superfamily.

It is highly expressed in hepatocellular, gastric, and colorectal cancers but restricted in normal tissues — an attractive ADC target.

High tumor specificity: in normal tissue, expression is limited to the gut.

High endocytosis efficiency into tumor cells.

Unmet need: many resistant patients in liver and gastric cancers.

Representatives: Puzhong Discovery's AMT-676 (IND 2024), Huadong Medicine's HDM2017 (FDA IND 2025), and Duoxi Bio's CDH17 ADC.

B7-H3 (CD276): A Rising Pan-Tumor Target

B7-H3 (CD276) is a member of the B7 immune-checkpoint family.

Overexpressed in multiple solid tumors (lung, breast, prostate, glioma) but restricted in normal tissues.

Pan-tumor coverage: large room for indication expansion.

Dual mechanism: usable as both an ADC target and an immune-checkpoint inhibitor target.

Competition: about 15 B7-H3 ADCs in development globally, with relatively mild competition.

Representatives: MacroGenics' MGC018 (Phase II), Hansoh's HS-20093 (NMPA Breakthrough Therapy in April 2026), and InnoCare's ICP-B794 (AACR 2026 data).

PTK7: A New Blue Ocean in Lung Cancer

PTK7 (protein tyrosine kinase 7) is highly expressed in multiple tumors.

It is particularly specific in NSCLC, an ADC target that has attracted significant recent attention.

NSCLC is one of the world's largest oncology markets with substantial unmet need.

PTK7 is expressed at low levels in normal lung tissue, providing a favorable safety window.

Kelun-Biotech's SKB518 became the world's first PTK7 ADC to enter Phase II (September 2025).

CLDN6: A Dual Identity in Germ Cells and Tumors

CLDN6 (Claudin-6) is a member of the claudin family of tight-junction proteins.

Highly expressed in fetal tissues but nearly absent in adult tissues.

But reactivated in multiple solid tumors (ovarian, lung, testicular).

Very high tumor specificity: virtually no expression in normal adult tissue.

AMG 794 (Amgen) and TORL-1 (Torque) have shown promising data.

Bispecific CLDN6/4 ADCs are emerging as a new R&D direction.

Opportunities for Chinese Players: From Follower to Leader

The Global Reach of Chinese ADCs

At AACR 2026, Chinese companies showcased more than 250 innovative drugs, including 92 ADCs.

Mature linker-payload platforms (hydrophilic linkers; novel payloads such as Exatecan and Deruxtecan derivatives).

Strong antibody discovery and engineering capabilities (hybridoma, phage display, single-domain antibodies).

Cost advantages and highly efficient clinical execution.

Differentiated target portfolios; some targets (e.g., CDH17) are in sync with global peers.

Investment and Partnership Opportunities

Bispecific ADC platforms: Companies with proprietary bispecific technologies, such as Duality Biologics and ProfoundBio.

Novel payloads: ADCs using highly potent payloads such as Exatecan and eribulin, e.g., Duoxi Bio and RemeGen.

Fast-follow on emerging targets: CDH17, B7-H3, etc., e.g., CSPC and Hengrui.

Global clinical capability: ADCs with US-China dual-filing experience, e.g., Kelun-Biotech and Duality Biologics.

Closing: The "No-Man's-Land" ADC War Has Just Begun

Crowding of HER2, TROP2, and Claudin18.2 is undeniable.

Yet ADC innovation is far from hitting a ceiling.

The rise of emerging targets such as CDH17, B7-H3, PTK7, and CLDN6 gives companies a chance to compete on differentiation.

For CROs/CDMOs with the right technology base, ADC CDMO is a blue ocean worth focusing on.

Disclaimer: For industry discussion only; not investment advice.

Data sources: AACR 2025/2026, PharmCube, ClinicalTrials.gov, public media.