Stcube
Spearheading The Revolution In Immuno-Oncology

Ever since Rituximab—the first monoclonal antibody for the treatment of cancer—was approved in 1997, immunotherapies against cancer have raised great hopes. The idea of cancer immunotherapy–harnessing the body’s own immune system to detect and destroy tumor cells–has been evolving by leaps and bounds and is geared to transition from preclinical studies in laboratories to practical application in clinics. Immunotherapy is emerging as a multibillion-dollar market for companies, large and small, racing to develop promising cancer-treating drugs, including monoclonal antibodies, checkpoint inhibitors, and more. With a strong focus on finding and exploiting new targets in the immuno-oncology field, STCube develops therapies to overcome novel immune evasion mechanisms in cancer. Through innovative new drug development technology, the company has been able to secure a number of pipeline candidates for innovative new drugs (First in Class) and improved new drugs (Best in Class) substances.

Focused on finding novel and improved immunotherapy for cancer, STCube has been successful in discovering new targets and developing antibodies against them. The company is equipped with its proprietary platform technologies for new drug development, spanning from the identification of candidates to the selection of specific ICP Inhibitors. “Our cutting-edge methodology and platform technologies are highly effective and novel,” says Hoon Choi, VP, Legal and Alliance at STCube. “We are in the early stage to develop our first lead candidate into clinics and aim to initiate the clinical trial by the fourth quarter of this year. We hope our novel immunotherapy will provide the much-needed solution for cancer patients resistant/refractory to PD-1/PD-L1 and other marketed immunotherapy.”

Developing a Novel Immune Checkpoint Blockade: Anti-BTN1A1 Antibody

Choi expounds that immune checkpoint blockade is an effective cancer treatment for certain late-stage tumors. The PD-1/PD-L1 axis has provided successful therapeutic targets in developing immune checkpoint blockades, but a certain proportion of cancer patients are still not responsive to anti-PD-1/PD-L1 antibodies.

Butyrophilin (BTN) belongs to the B7 family that contains an immunoglobulin domain found in PD-L1. “While BTN2A2 and BTN3A1 are identified as co-inhibitory or co-stimulatory cancer immune checkpoint(s) regulating the effector T cell compartment, the immune-modulatory role(s) of BTN1A1 has been largely unknown. We are one of the few in the industry to target BTN1A1 of the BTN family. This is the first target that we identified using our proprietary discovery platform,” asserts Choi.

Human BTN1A1 (hBTN1A1) is prominently expressed in various tumor tissues, including lung, bladder, ovary, uterine cervix, breast, H&N, or esophagus tumors.

Our cutting-edge methodology and platform technologies are highly effective and novel

Choi goes on to explain that the expression of BTN1A1 is mutually exclusive to that of PD-L1 on cancer cells. Put simply, BTN1A1 protein does not express itself when PD-L1 is in play.This observation suggests that BTN1A1 may operate as the immune checkpoint independent of the PD-1/PD-L1 axis. STCube has developed the monoclonal antibody (STC810) against hBTN1A1. STC810 has anti-tumor activity in a human immune environment in vitro and ex vivo and has been humanized (hSTC810).

STCube has drawn two interpretations from the interesting behavior of BTN1A1.

• Patients can be responsive to PD-1/PD-L1 for a while and then become resistant/refractory to them. This is where BTN1A1 may come in and take over the immune evasion mechanism on tumor cells.
In this case, it is safe to say that the antibody that STCube is developing is extremely efficacious for patients who are resistant/refractory to PD-1/PD-L1 therapy.
• In certain types of cancer, there is minimal or absolutely zero expression of PD-1/PD-L1. This results in the high expression of BTN1A1.
Again, here, the company’s novel drug can prove highly effective against cancers unresponsive to PD-1/PD-L1 therapy.

Journey through the Years

With extensive experience in the field of immunotherapy for cancer, Hyunjin Jung, the CEO of STCube, came up with cell-based therapy in his former company, Innocell (currently, Green Cross Cell), which was later acquired by a leading Korean company. This was when he purchased the stocks of his current company (STCube) and converted it into a bio company. The history began when Dr. Jung and Stephen S. Yoo, Former Branch Chief, Molecular Radiation Therapeutics Branch, at NCI, joined hands to develop drugs for immuno-oncology targets. Since then, the company has collaborated with various institutional investigators, like MD Anderson and other U.S. Institutions, establishing STCube’s discovery platform and discovering interesting targets that can potentially be a blockbuster in the field. With Dr. Jung at the helm, STCube exclusively focuses on administration, strategy, and finance. On the other hand, Dr. Yoo leads the company’s U.S. branch, STCube Pharmaceuticals—a wholly-owned subsidiary of STCube—responsible for research.

STCube’s upcoming endeavors and growth opportunities are new chapters to be written. With a near-term goal to receive approval for its Investigational New Drug (IND), the company plans to start the phase I clinical trial with hSTC810 in the fourth quarter of 2021. STCube aims to develop the pipeline molecules into clinics by either independently allocating the required funds or partnering with leading pharma companies. Additionally, the company has identified several candidates by leveraging its discovery platform, which are being developed at various stages in the pipeline. “We constantly focus on developing cutting-edge immunotherapies for the benefit of cancer patients,” notes Choi.