ADC-Payload™

Proprietary ADC payload platforms delivering superior therapeutic index through novel mechanisms of action.

Platform Overview

ADC-Payload™ Platform: Next-Generation ADC Payload Technologies

The clinical success of antibody-drug conjugates (ADCs) is often limited by a narrow therapeutic index—balancing potent tumor killing with acceptable off-target toxicity. To address this critical challenge, Protheragen proudly introduces our ADC-Payload™ platform, a portfolio of proprietary, in-house developed payload technologies. This platform encompasses two distinct classes of novel cytotoxic agents: MTi™ (Microtubule Inhibitors) and TOPi™ (Topoisomerase I Inhibitors). By offering diverse mechanisms of action, ADC-Payload™ enables the development of ADCs with optimized efficacy, reduced toxicity, and expanded therapeutic windows, forming the foundation for next-generation antibody-based cancer therapies.

Disruptive Technology
Excellent Team
Diversified Pipeline
Customized Solutions

Platform Core

ADC-Payload™: A Portfolio of Novel Payloads with Distinct Mechanisms of Action

The ADC-Payload™ platform consists of two proprietary payload families, each targeting a fundamental pathway in cancer cell division. Both payload families are optimized for ADC conjugation, featuring stable linker attachment sites and controlled bystander effects, allowing for flexible ADC design tailored to specific tumor biology.

MTi™ (Microtubule Inhibitors): This class of payloads disrupts microtubule dynamics, arresting cells in the G2/M phase of the cell cycle and leading to apoptosis. These agents are highly potent against rapidly dividing tumor cells.
TOPi™ (Topoisomerase I Inhibitors): This class of payloads targets topoisomerase I, an enzyme critical for DNA replication. By stabilizing the DNA-topoisomerase I complex, these agents induce irreversible DNA damage, resulting in cancer cell death.

Platform Advantages

Unique Advantages of the ADC-Payload™ Platform

Dual-Mechanism Payload Portfolio

Unlike conventional ADC platforms that rely on a single payload class, ADC-Payload™ offers two distinct families of cytotoxic agents—microtubule inhibitors (MTi™) and topoisomerase I inhibitors (TOPi™). This enables strategic matching of payload mechanism to target biology, overcoming resistance mechanisms and expanding treatment options for diverse tumor types.

Optimized Therapeutic Index

Our proprietary payloads are designed from the ground up to balance high potency against cancer cells with reduced off-target toxicity. By fine-tuning physiochemical properties and bystander effects, ADC-Payload™ enables ADCs that achieve superior tumor regression at well-tolerated doses, addressing the primary bottleneck in ADC clinical development.

Versatile Nucleic Acid Cargo Compatibility

Broad Compatibility with ADC Architectures

The ADC-Payload™ platform is engineered for versatility. Both MTi™ and TOPi™ payloads are compatible with standard linker technologies and can be deployed across multiple ADC formats, including classic ADCs, bispecific ADCs, and bifunctional ADCs that combine chemoactivity with immune-modulating functions.

Platform Application

Empowering Innovative ADC Development

Classic ADC Development ADC-Payload™ payloads serve as the foundation for conventional ADCs targeting tumor-associated antigens. By conjugating MTi™ or TOPi™ payloads to validated antibodies, our partners can develop next-generation ADCs with improved efficacy and safety profiles across solid tumors and hematologic malignancies.
Bispecific ADC Development The platform enables the creation of bispecific ADCs that engage two distinct tumor-associated antigens. This dual-targeting approach enhances tumor specificity, reduces off-tumor toxicity, and overcomes antigen heterogeneity—a major challenge in solid tumor therapy.
Bifunctional ADC Development Beyond traditional cytotoxic activity, ADC-Payload™ payloads can be incorporated into bifunctional ADCs that combine direct tumor killing with immune-modulating functions. These innovative constructs actively engage the tumor microenvironment, converting “cold” tumors into “hot” tumors responsive to immunotherapy.

Pipeline

Research & Development Pipeline

Projects	Target	Strategy	Payload	Indication
ADC007	TROP2	Indication differentiation	MTi™	Solid Tumor
ADC015	Undisclosed	FIC	Undisclosed	Solid Tumor
ADC021	Undisclosed	FIC	Undisclosed	AML
ADC026	Undisclosed	BIC	Undisclosed	Solid Tumor
ADC030	Undisclosed	FIC/BIC	Undisclosed	Solid Tumor
ADC032	Undisclosed	FIC	Undisclosed	Solid Tumor
ADC035	Undisclosed	FIC	Undisclosed	Solid Tumor

Get in Touch with Us

FAQs

Frequently Asked Questions

Q1: What distinguishes MTi™ from TOPi™ payloads? A: MTi™ payloads are microtubule inhibitors that arrest cells in the G2/M phase, while TOPi™ payloads are topoisomerase I inhibitors that induce DNA damage. This mechanistic diversity allows us to select the optimal payload based on tumor biology, proliferation rate, and resistance mechanisms.
Q2: Are these payloads compatible with existing ADC linker technologies? A: Yes. Both MTi™ and TOPi™ payloads are designed with versatile conjugation sites, making them compatible with a wide range of stable and cleavable linkers. This flexibility allows seamless integration into existing ADC development workflows.
Q3: What is the drug-to-antibody ratio (DAR) achievable with ADC-Payload™? A: Our payloads are optimized to achieve precise DAR values (typically 2, 4, or 8) with high homogeneity. The conjugation process maintains antibody integrity and yields consistent product quality suitable for preclinical and clinical development.
Q4: How do ADC-Payload™ payloads address the bystander effect? A: The bystander effect can be tuned based on payload properties. Our TOPi™ payloads can be optimized for moderate bystander activity to eliminate neighboring antigen-negative tumor cells, while MTi™ payloads can be configured with limited bystander activity when precise targeting is required. This tunability enables application-specific optimization.
Q5: Can ADC-Payload™ payloads be used for non-oncology indications? A: While primarily developed for oncology, the platform's targeting versatility supports exploration of ADC applications in other diseases where selective cell depletion is beneficial, such as autoimmune disorders or infectious diseases.