Medigene Presents Progress on KRAS Library and UniTope & TraCR Technology at ESMO 2024

Planegg/Martinsried, September 14, 2024. Medigene AG (Medigene or the “Company”, FSE: MDG1, Prime Standard), an oncology platform company focused on the research and development of T cell receptor (TCR)-guided therapies for the treatment of cancer, presented updates for its T cell receptor (TCR) library targeting the Kirsten rat sarcoma viral oncogene homolog (KRAS) and also highlighted advancements of its UniTope and TraCR technology, which serves as a universal system for tagging and tracking recombinant TCRs (rTCRs) across multiple modalities, including T cell receptor engineered T cell (TCR-T) therapies, at the ESMO Congress 2024 taking place in Barcelona from September 13-17, 2024. The presented posters “Advancing a multi-dimension KRAS mutation-specific T cell receptor (TCR) library with a 3S TCR targeting the G12D mutation to address large global patient populations” and “UniTope & TraCR – Universal tagging and tracking system for TCR-T cells integrated directly in the TCR constant region” will be made available after the conference on Medigene’s website: https://medigene.com/science/abstracts/ “We are excited about our expanding library of mKRAS-specific rTCRs targeting different mutations and HLA allotypes, aiming to broaden treatment options and improve outcomes for patients with difficult-to-treat solid tumors,” said Dolores Schendel, CSO at Medigene AG. “Our lead KRAS G12D candidate, enhanced by the costimulatory switch protein (CSP) PD1-41BB, has shown very promising T cell functionality. By overcoming the challenges of the tumor microenvironment that have hindered the effectiveness of TCR-T therapies, we are confident that this program could offer best-in-class efficacy and safety. We are expanding our TCR library and also incorporating new proprietary technologies into our End-to-End (E2E) Platform, including UniTope & TraCR, a universal detection system for any rTCR across various modalities like TCR-T therapies, TCR-guided T cell engagers therapies, and TCR-NK cell therapies. Direct integration of the UniTope tag guarantees 100% co-expression of a unique identifier in a rTCR sequence and provides a significant advancement over current methods for detection of rTCRs in TCR-guided therapeutics. UniTope and TraCR will help us streamline quality control and provide precise data for determining the correct drug dosing for TCR-T therapies.” Advancing a multi-dimension KRAS mutation-specific T cell receptor (TCR) library with a 3S TCR targeting the G12D mutation to address large global patient populations The first data presented showcased recent advancements in the expansion of the Company’s KRAS library, using a high-throughput approach to develop optimal affinity TCRs targeting the mKRAS G12D neoantigen in the context of HLA-A*11 via Medigene’s proprietary E2E Platform. Further in vitro studies characterized the lead TCR candidate in terms of specificity, sensitivity, and safety (3S) while incorporating the PD1-41BB CSP. TCR-expressing T cells, when stimulated by mKRAS G12D-positive tumor cells, showed increased interferon gamma (IFNγ) release. Reduced cancer cell survival was observed when mKRAS G12D-positive tumor cell lines from various origins were exposed to T cells co-expressing the rTCR mKRAS G12D-HLA-A*11 and PD1-41BB CSP. These effects were specific to mKRAS G12D, with no impact on wild-type KRAS cells. The TCR demonstrated an excellent safety profile, with no off-target toxicity against an extensive panel of healthy cell types. Finally, in vitro data showed that co-expression of PD1-41BB CSP enhanced and sustained T cell function in an rTCR-specific manner, with gated activation that only occurred when the specific peptide-HLA complex was present on target cells, and not through PD-L1 expression alone. UniTope & TraCR – Universal tagging and tracking system for TCR-T cells integrated directly in the TCR constant region The second poster displayed the Company´s recently introduced universal TCR tagging and tracking combination technology UniTope & TraCR. Bioinformatic alignment of T cell receptor beta variable sequences enabled a six-amino-acid peptide (UniTope) to be predicted that is not found in natural TCR beta chains and has low immunogenicity. In parallel, an antibody was developed to specifically target this short amino acid peptide (TraCR) and further in vitro experiments demonstrated that TCR-T cells containing the UniTope sequence exhibited similar effects to those of TCR-T cells without the UniTope sequence. Integration of the UniTope sequence in a rTCR guarantees 100% co-expression of the tag and provides a significant advancement over current methods of detection of rTCRs in TCR-guided therapeutics. In vitro studies confirmed that insertion of UniTope did not alter expression or functionality of rTCRs. In addition, safety assessments confirmed that UniTope-modified rTCRs displayed the same high safety profile as un-modified rTCRs with respect to lack of recognition and killing of 16 healthy cell types. —  end of press release  — About Medigene AG Medigene AG (FSE: MDG1) is an immuno-oncology platform company dedicated to developing T cell receptor (TCR)-guided therapies to effectively eliminate cancer. Its End-to-End Platform generates optimal 3S (sensitive, specific and safe) T cell receptors with unique and distinctive attributes that are utilized in multiple therapeutic modalities, such as T cell receptor engineered T cell (TCR-T) therapies, TCR-guided T cell engager therapies and TCR-natural killer cell therapies for both its in-house product pipeline and partnering. Medigene’s lead TCR-T program MDG1015 is a potential best-in-class, TCR-T therapy to treat multiple solid tumor indications. The End-to-End Platform technologies enable armoring and enhancing of these T cells to overcome the immunosuppressive tumor microenvironment (TME) and ensure the T cell drug product composition maximizes safety, efficacy and durability of response. Medigene’s MDG1015 received IND approval in Q3 2024 and is filing for CTA in Q4 2024. For more information, please visit https://medigene.com/ About Medigene’s End-to-End Platform Medigene’s approach to immunotherapy harnesses the immense power of natural T cell receptors. By combining these TCRs with different components of the immune system such as T cells, natural killer (NK) cells or a CD3 complex (TCE, T cell engager), highly specific, sensitive and safe modalities are formed to either complement and/or activate the body’s defense systems against cancer. Medigene’s comprehensive End-to-End (E2E) Platform is built on a foundation of proprietary and cutting-edge technologies, driving the development of highly specific TCR-guided therapies, including the latest advancements in TCR-T, TCR-NK and TCR-TCE drug products. The E2E Platform incorporates sophisticated TCR generation and optimization techniques, such as Allogeneic-HLA TCR Priming, and integrates advanced product armoring and enhancement features like PD1-41BB and CD40L-CD28 Costimulatory Switch Proteins, and iM-TCR. In addition, the E2E Platform offers solutions to developing optimal cell therapy drug products for improved safety, efficacy and durability. Collaborations with partners like BioNTech, Regeneron and WuXi Biologics further underscore the platform’s capabilities and its potential to revolutionize cancer treatment. About KRASKRAS (Kirsten rat sarcoma viral oncogene homologue) belongs to the group of small so-called Guanosine-5′-triphosphate (GTP)-binding proteins, known as RAS-like GTPases. Under physiological conditions KRAS tightly regulates cell proliferation and survival. In cancer, KRAS is found frequently altered, in a wide variety of often fatal solid cancer types like pancreatic ductal adenocarcinoma, non-small-cell lung cancer, and colorectal cancer. Mutations in the KRAS gene result in the creation of neoantigens which drive uncontrolled proliferation of cancer cells. These mutations within the KRAS gene are unique to cancer cells and absent in healthy normal tissue, making KRAS an attractive target for TCR-T therapies. T cell receptor engineered T cell therapies offer a promising approach to targeting these mutations and addressing the challenges posed by solid tumors. Unlike CAR-T cells, which require surface antigens for recognition and may have limitations in target accessibility, TCR-T cells recognize a broader range of targets including intracellular proteins like neoantigens. This unique ability makes TCR-T therapies particularly well-suited for targeting KRAS mutations and other challenging neoantigens. About Medigene’s PD1-41BB Costimulatory Switch Protein Checkpoint inhibition via PD-1/PD-L1 pathway: Cells of solid tumors are sensitive to killing by activated T cells but can escape this killing activity by producing inhibitory molecules known as ‘checkpoint proteins’, such as the Programmed Death Ligand 1 (PD-L1), on their surface. When this occurs, activated T cells which express PD-1, the natural receptor for PD-L1, are inactivated. The expression of PD-L1 is an adaptive immune resistance mechanism for tumors that can help them survive and grow. The 4-1BB (CD137) costimulatory signaling pathway: Effective T cell immune responses to antigens typically require both a primary antigenic stimulation via the T cell receptor (TCR) and costimulatory signals. The intracellular signaling domains of the 4-1BB protein offer a well-characterized pathway to costimulation and enhanced T cell responses. Medigene’s PD1-41BB switch receptor turns the tumor’s attempted self-defense mechanism against the tumor by substituting the inhibitory signaling domain of PD-1 with the activating signaling domain of 4-1BB. Therefore, instead of inactivating T cells, the switch receptor delivers an activating signal to TCR-T cells. PD1-41BB-modified TCR-T cells proliferate strongly in the presence of PD-L1-positive tumor cells and kill more tumor cells upon repeated exposure. Additionally, switch receptor signals enable TCR-T cells to function better with low levels of glucose or high levels of TGFß, two conditions characteristic of strongly hostile tumor microenvironments. This press release contains forward-looking statements representing the opinion of Medigene as of the date of this release. The actual results achieved by Medigene may differ significantly from the forward-looking statements made herein. Medigene is not bound to update any of these forward-looking statements. Medigene® is a registered trademark of Medigene AG. This trademark may be owned or licensed in select locations only. Medigene AG Pamela Keck Phone: +49 89 2000 3333 01 E-mail: [email protected] In case you no longer wish to receive any information about Medigene, please inform us by e-mail ([email protected]). We will then delete your address from our distribution list.