SystImmune to Present Data from Seven Preclinical Programs at the American Association of Cancer Research (AACR) Annual Meeting 2023

Results from preclinical development programs for tetraspecific GNC T cell engagers extend the feasibility of this multi-specific drug class.

Data from the bi-specific antibody-drug conjugate (ADC) targeting EGFR and HER3 will be presented, proceeding a clinical presentation at the American Society of Clinical Oncology (ASCO) Chicago 2023

Redmond, WA – SystImmune, Inc (“SystImmune”), a clinical-stage biopharmaceutical company specializing in the development of innovative cancer treatments using its established drug development platforms, has announced that it will present data from seven preclinical programs in poster presentations at the American Association of Cancer Research (AACR) meeting, which will be held in Orlando, FL, from April 14th to 19th, 2023.

“Our seven posters presented at AACR represent the important studies in three therapeutic modalities, which demonstrate the continuous innovation happening at SystImmune. The preclinical validation of the intended functionality and the preclinical safety is encouraging. SystImmune looks forward to the clinical validation of the therapeutic concepts that we build into our biologics platforms.” said Dr. Yi Zhu, Ph.D. President & CEO of SystImmune."

"SystImmune is excited to have the opportunity to present our preclinical drug data at AACR. We're proud of the significant progress made over the last years, and we're committed to continuing our efforts to deliver high-quality treatments that meet the unmet needs of patients in the field of oncology," said Dr. Martin Olivo, M.D. CMO of SystImmune.

SystImmune will present its findings in several poster sessions at the AACR meeting, including "Antibody Technologies," "Therapeutic Antibodies, Including Engineered Antibodies," and "Growth Factor Receptors as Therapeutic Targets."

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On April 17th, 2023, in the session entitled "Antibody Technologies," the company will present its antibody-drug conjugate preclinical progress:

Abstract Name: BL-B01D1, a novelEGFR×HER3-targeting ADC, demonstrates robust anti-tumor efficacy in preclinical evaluation.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #2642 Poster Link

Abstract Name: BL-M07D1, a novelHER2-targeting ADC, demonstrates potent anti-tumor efficacy in preclinical pharmacodynamic models.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #2643 Poster Link

Abstract Name: BL-M02D1, a novel Trop2-targeting ADC, demonstrates robust anti-tumor efficacy in preclinical evaluation.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #2644 Poster link

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On April 18th, 2023, in the session entitled "Therapeutic Antibodies, Including Engineered Antibodies," the company will present its Tetra-specific T-cell engager technology:

Abstract Name: Tetra-specific antibody GNC-035: guidance and navigation control (GNC) molecule development for treatment of ROR1+ malignancies.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #5679 Poster Link

Abstract Name: Tetra-specific antibody GNC-039: guidance and navigation control (GNC) molecule development for treatment of EGFRvIII+ malignancies.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #5680 Poster Link

Abstract Name: Tetra-specific antibody GNC-038: guidance and navigation control (GNC) molecule development for treatment of CD19+ malignancies.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #5681 Poster Link

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On April 19th, 2023, in the session entitled "Growth Factor Receptors as Therapeutic Targets," the company will present its advanced Bi-specific EGFR and HER3 antibody:

Abstract Name: Anti-tumor efficacy of SI-B001, a novel EGFR×HER3 bispecific antibody, against EGFR-driven epithelial tumors alone or in combination with paclitaxel and carboplatin.

Presenter: Jahan S. Khalili, Ph.D.

Presentation Details: Abstract #6309 Poster Link

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SystImmune Drug Platforms

SEBA

The Specificity Enhanced Bi-specific Antibody (SEBA) is a type of oncology therapeutic that can target functional proteins found on the surface of cancer cells. By blocking the growth signals that cancer cells rely on for survival, SEBA technology holds significant promise for cancer treatment. SEBA molecules are developed to have dependent binding toward one of its targets to increase selectivity and reduce toxicity.

Representative of the SEBA platform is izalontamab (SI-B001) which binds EGFR and HER3 with an EGFR dependency for HER3 engagement.?Several novel SEBA molecules targeting growth factor receptors and bi-specific immunomodulators are also in development on this platform.

HIRE

Antibody?Drug Conjugate (ADC) molecules utilize specific antibodies to deliver therapeutic small molecules to cancer cells. These molecules are created in cooperation with Bai-Li Pharmaceutical's R&D Center of Excellence and enable the development of sophisticated chemistries that give this class of drugs their therapeutic payload. SystImmune’s advanced functional ADC platform class is known as heterogeneity?overcoming, immunogenic death-inducing, resistance?antagonizing, Enhanced?Specificity (HIRE).

Representative of the HIRE platform is BL-B01D1 which binds EGFR and HER3 with an EGFR dependency for HER3 engagement and delivers a DAR-8 Topoisomerase?I?inhibiting payload that mediates immunogenic cell death and potent bystander killing. The ADCs BL-M07D1 and BL-M02D1 are also included in this platform class. The HIRE platform is responsible for producing several differentially binding mono-specific, bi?specific and bi-paratopic ADCs at various stages of preclinical development that are advancing from discovery to the pre-IND stage.

GNC

Guidance and navigation control (GNC) molecules are proteins that bind and engage multiple types of cells. In oncology therapeutics, GNCs bind to both cancer cells and immune cells, thereby boosting the immune cell's ability to eliminate cancer. Each GNC molecule is designed to be multi-functional, with the aim of modulating the immune cell compartments during the killing process and making them more effective in targeting cancer cells.

Representative of the GNC platform is GNC-038, an octavalent, tetra-specific T cell engager designed to target CD19 expressing B cell malignancies. This molecule is the first tetra-specific therapeutic antibody tested in humans and exemplifies the concept of GNCs.

GNC-038 can bind CD3 and CD19 to redirect T cell cytotoxicity toward a specified cancer indication defined by CD19 expression. The molecule can also redirect T cell cytotoxicity toward PDL1 high-expressing cells, representing its potential to convert cancer?cell adaptive resistance into drug sensitivity. GNC-038 can also engage 4-1BB, an activation-induced T?cell costimulatory molecule, in a non-cytolytic fashion, transducing a signal to T cells that are designed to increase functionality throughout serial dosing cycles of therapy.?

Alongside GNC-038 are GNC-035 targeting ROR1 and GNC-039targeting EGFRvIII tumor antigens, respectively.

About SystImmune

SystImmune is a clinical-stage biopharmaceutical company located in Redmond, WA. It specializes in developing innovative cancer treatments using its established drug development platforms, focusing on bi-specific, multi-specific antibodies, and antibody-drug conjugates (ADCs). SystImmune has several assets in various stages of clinical trials for solid tumor and hematologic indications. Alongside ongoing clinical trials, SystImmune has a robust preclinical pipeline of potential cancer therapeutics in the discovery or IND-enabling stages, representing cutting-edge biologics development.?