Anti-HER2 and Anti-HER3 monoclonal antibodies designed to have a high drug-to-antibody ratio intended enhance the bystander killing effect and be effective against a number of epithelial tumors

Antibody CDRs against HER2 and HER3 Conformational Domain Bridging Epitopes can be used in multiple formats including bi- and tri-specific antibodies, antibody drug conjugates (ADCs), CAR-T and CAR-NKs

BRIDGEWATER, NJ, USA I July 06, 2023 I Hillstream BioPharma, Inc. (Nasdaq: HILS) (“Hillstream” or the “Company”), a biotechnology company developing therapeutic candidates targeting drug resistant and devastating cancers using immuno-oncology targeted novel biologics, today announced the signing of an exclusive agreement with Applied Biomedical Science Institute (ABSI) to license technology for human antibodies targeting novel HER2 and HER3 Conformational Epitopes. The goal is to develop proprietary multi-format biologics, including bi-specific antibodies, and antibody drug conjugates (ADCs). The HER2/HER3 binding ADC is targeted to have a high drug-to-antibody ratio which should increase the anti-tumoral efficacy with an enhanced bystander killing effect. Hillstream intends to combat drug resistant cancers such as HER2-positive metastatic breast cancer, gastric cancer, lung cancer and ovarian cancer.

The ErbB family of cell surface proteins, including ErbB2 or HER2 (human epidermal growth factor receptor) and Erb3 or HER3, are some of the most well-known and validated oncology drug targets. Antibodies and biologics against HER2 starting with HERCEPTIN® (trastuzumab) approved in 1998 for breast cancer, and PERJETA®, KADCYLA® and PHESGO® generated $8.4 billion in 2022 sales for Roche/Genentech. These antibodies bind to domains II or IV of the extracellular portion of the HER2. HER2 is also one of the most validated antigens for antibody drug conjugates (ADCs) to treat HER2 positive cancers with two approved antibodies, Roche/Genentech’s KADCYLA® and Daiichi Sankyo/AstraZeneca’s ENHERTU®.

The Applied Biomedical Science Institute has developed technology to target novel functional epitopes of the cancer targets HER2 and HER3. The monoclonal antibodies being developed at ABSI are distinct from the currently approved anti-HER2 antibodies. ABSI has granted Hillstream an exclusive license agreement, and Hillstream will have the opportunity to develop HER2 and HER3 antibodies, including multi-specific, ADC, and Quatramer-based therapeutics utilizing portions of these antibodies.

“We look forward to this opportunity to work with Dr. Smider and the Applied Biomedical Science Institute,” said Randy Milby, CEO of Hillstream. “This agreement allows us to build our antibody platform to advance our immune-oncology biologic pipeline with HER2 and HER3 with bi-specifics and ADC agents targeting highly aggressive drug-resistant metastatic tumors, which represents a major unmet need for patients.”

About Applied Biomedical Science Institute
The Applied Biomedical Science Institute (ABSI) is a 501(c)(3) non-profit organization taking a leading role in basic research and its rapid clinical translation by performing cutting-edge basic and translational research. With deep expertise in antibody genetics, biology, engineering, and discovery technologies, ABSI promotes therapeutic and diagnostic translation through their own internal research, collaborations, or licensing activities. ABSI also trains early-stage researchers in biomedical research through post-doctoral fellow and internship programs.

About Hillstream BioPharma, Inc.
Hillstream BioPharma, Inc. is a biotechnology company developing novel therapeutic candidates against drug-resistant and devastating cancers. Hillstream uses Quatramer™, a proprietary tumor targeting platform which extends duration of action and minimizes off-target toxicity, with biologics, mRNA, peptides and other modalities in the tumor microenvironment. Quatrabody™ conjugates immuno-oncology targets with greater binding affinity than approved therapies. Hillstream Quatramers with novel biologics developed against proprietary undruggable epitopes of PD-1 and other validated will enter the rapidly growing immuno-oncology therapeutics market leading with HSB-1940, targeting PD-1, followed by additional targets including PD-L1, HER-2 and TROP-2. For more information, please visit:

SOURCE: Hillstram BioPharma