Abalos Therapeutics Publishes in Cell Reports Medicine Validating ABX-001’s Potential to Overcome Cancer Immunotherapy Hurdles

-- Preclinical data support Abalos’ first-in-class approach of safely harnessing the immunostimulatory and anti-tumoral properties of arenaviruses to treat solid tumors -- 
  

Düsseldorf, Germany, October 14, 2025 – Abalos Therapeutics announced today the publication of preclinical proof-of-concept data for the company’s immunoactivating lead candidate, ABX-001, in Cell Reports Medicine, highlighting its potential as a powerful new drug class in cancer treatment. Through ABX-001’s capability to systemically activate both innate (immediate) and adaptive (memory) immune responses with a single administration, Abalos aims to reach new levels of immune system engagement and address current limitations in immunotherapy.

The publication titled “Optimized arenavirus design with tumor-tropic mutations promote safety and anti-tumor efficacy via sustainable immune modulatory properties” provides a comprehensive overview of the development and evaluation of ABX-001, the first drug candidate leveraging Abalos’ proprietary AdaptInnate approach. Abalos developed ABX-001 as therapeutic candidate by optimizing a non-lytic arenavirus strain using strategic selections of specific mutations for immunostimulatory and anti-tumoral properties, including high tumor-tropism and minimal replication in healthy cells. Importantly, ABX-001’s mode of action is characterized by persistent and sustained replication in cancerous as well as antigen-presenting cells without destroying them. This results in exceptional induction of effector T-cells and actively guides immune cells into the tumor. This novel, non-oncolytic approach for systemic use is designed to induce a targeted, effective, and durable anti-cancer activity against primary tumors and tumor cells that have migrated to other regions of the body, so called metastases.

“The publication in Cell Reports Medicine underscores the potential of our novel anti-cancer approach as a promising alternative for patients who face the limitations of current immunotherapies,” said Jörg Vollmer, CSO at Abalos. “By safely engaging all major lymphatic organs in a coordinated, body-wide attack against tumors, we aim to overcome key challenges such as immune evasion of cancer cells, inadequate T cell activation, and tumor heterogeneity. The strong safety profile and robust anti-cancer activity demonstrated across a range of clinically relevant solid tumor models provide a solid foundation for the clinical development of ABX-001, with the first-in-human trial expected to begin soon.”

In a variety of murine solid tumor models, ABX-001 exhibited strong anti-tumoral efficacy by inducing the expansion of tumor-specific T cells and immune-activating cytokines such as IFN-γ. Notably, mice with complete tumor remission upon systemic ABX-001 treatment were protected from tumor cell re-challenge, suggesting long-lasting anti-tumoral immunity. The candidate demonstrated a favorable safety profile, with minimal viral replication in healthy tissues and no severe disease symptoms in arenavirus-susceptible mice. The results were replicated in non-human primates highly sensitive to wildtype arenaviruses. Here, treatment with ABX-001 led to substantially increased levels of immunostimulatory cytokines and chemokines as well as significantly increased expansion of monocytes, CD4⁺ and CD8⁺ T cells. The CD4⁺/CD8⁺ ratio decreased after ABX-001 application, reflecting the strong priming of cytotoxic T cells triggered by the candidate. Despite this strong immune activation, no adverse effects were observed at any dose level or timepoint, demonstrating a highly favorable safety profile.

Data on the development of ABX-001 and its demonstrated proprietary anti-tumoral efficacy in a range of in vitro and in vivo models will be presented at the European Society for Medical Oncology (ESMO) Congress 2025.

Presentation Details:

Poster presentation
Abstract Title: Optimized arenavirus design with tumor-tropic mutations accelerates anti-tumor efficacy of lymphocytic choriomeningitis sustainable immune modulatory properties
Date: Monday, October 20, 2025
Presenter: Prof. Karl S Lang, PhD, Chair of Immunology at the Medical Faculty, University Duisburg-Essen and Scientific Founder of Abalos
Location: Poster Session 2, Hall 25, Messe Berlin, Germany
Poster Number: #342

Based on the encouraging preclinical proof-of-concept data, Abalos is advancing ABX-001 into a Phase 1 first-in-human basket-style trial across sites in Europe.

About Abalos Therapeutics
Abalos Therapeutics is pioneering a novel anti-cancer approach that directs the full breadth of the immune system’s power specifically towards cancer cells. Abalos’ arenavirus-based drug candidates are designed to trigger precise innate and adaptive immune responses from within the tumor to engage all relevant immune cell types in a concerted attack against both the primary tumor and distant metastases. The company’s lead product candidate ABX-001 has demonstrated strong anti-tumor efficacy in pre-clinical studies in multiple tumor models as well as an excellent pre-clinical safety profile and will enter the clinic in 2025. Led by experienced biotech entrepreneurs and immunology pioneers, Abalos’ goal is to establish a new drug class in immuno-oncology. For more information, please visit www.abalos-tx.com.

For more information, please contact:

Abalos Therapeutics GmbH
Phone: +49 211 540104-0
Email: info@abalos-tx.com

Abalos media inquiries
Trophic Communications
Stephanie May / Marie-Theresa Weickert
Phone: +49 171 185 56 82
Email: abalos@trophic.eu