Engineered to overcome the inherent limitations of conventional ADC conjugation approaches

Our pipeline consists of differentiated ADCs discovered and developed using our proprietary expanded genetic code technology platform.

ADCs can be designed to treat a broad range of diseases and disorders. Our initial focus is on potential treatments of cancers with a high unmet medical need.

Ambrx ADC Oncology Programs

ARX788: anti-HER2 ADC
Anti-HER2 ADC (ARX788) — Oncology

Ambrx Partnered Programs

ARX305: Anti-CD70 ADC
ARX102: Smart PEG-IL2
Anti-CD3 Folate Bi-Specific
TLR-agonist Antibody Conjugates
Bi-Specific Platform

Collaboration Programs

Bio-Conjugates for Animal Health (multiple)
BeiGene Collaboration (multiple projects)


Our most advanced internal candidate is ARX788, an anti-HER2 ADC currently being studied broadly in breast cancer, gastric/GEJ cancer and other solid tumor clinical trials. The United States Food and Drug Administration (FDA) has granted Fast Track Designation for ARX788 in HER2+ metastatic breast cancer and Orphan Drug Designation for ARX788 in gastric cancer.

ARX788 is a homogeneous and highly stable ADC, which targets the HER2 receptor and contains two AS269 cytotoxic payloads site-specifically conjugated to a trastuzumab-based antibody. ARX788 was designed to maximize potential anti-tumor activity by optimizing the number and position of the payloads and the chemical bonds that conjugate the payloads to the antibody. AS269, our proprietary payload, is a tubulin inhibitor specifically designed to form a highly stable covalent bond with our SAAs and kill tumor cells only upon entry into the cell when aided by the conjugated targeting antibody, thereby limiting off-target effects on healthy tissue.


ARX517 targets the prostate-specific membrane antigen (PSMA) expressed on prostate cancer cells. PSMA is a clinically important biomarker of prostate cancer which is highly over-expressed in metastatic castration-resistant prostate cancer (mCRPC), as well as in solid tumors (such as pancreatic, non-small cell lung cancer (NSCLC) and ovarian). We received clearance of our investigation new drug (IND) application for ARX517 from the FDA and plan to advance into clinical investigation.


ARX305 targets the CD70 receptor on cancer cells. CD70 is over expressed in a broad range of solid and hematologic tumors such as renal cell carcinoma (RCC), nasopharyngeal cancers, multiple myeloma, non-Hodgkin’s lymphoma and acute myeloid leukemia (AML). We are currently conducting IND-enabling studies to support potential future clinical investigation.


Ambrx has a long track record of partnering with leading pharmaceutical companies to apply its technology platform to create Engineered Precision Biologics for broad therapeutic applications. Ambrx evaluates partnership opportunities for its ADC and IOC programs and platform with biopharmaceutical companies possessing complementary capabilities. For more information, please contact bd@ambrx.com.

Zhejiang Medicine/NovoCodex

In June of 2013 Ambrx entered into a collaboration with Zhejiang Medicine Co., Ltd., which was transferred to NovoCodex, to develop and commercialize ARX788, Ambrx’s most advanced internally developed site-specific ADC targeting HER2-positive breast cancer. Under the agreement, Ambrx and ZMC will continue the development of ARX788. ZMC received commercial rights in China while Ambrx retained commercial rights outside of China and receives royalties on sales of the product in China.

Sino Biopharmaceutical

In January 2020, Ambrx entered into a co-development and license agreement with Sino Biopharmaceutical for two Engineered Precision Biologics. Sino Biopharmaceutical was granted rights for development and commercialization of the two programs in China and specific additional territories, and Ambrx retains rights for the rest of the world.


In March 2019, Ambrx entered into an agreement with BeiGene focused on advancing next-generation biologic therapeutics. The partnership combines Ambrx’s technologies for site-specific modification of proteins and incorporation of non-natural amino acids into proteins with BeiGene’s expertise in innovative molecularly-targeted and immuno-oncology drugs for the treatment of cancer.