OSE Immunotherapeutics

Regulatory Filings • Mar 21, 2022

OSE Immunotherapeutics Receives First Notice of Allowance for a US Patent Covering Anti-PD1 Monoclonal Antibody OSE-279 And its Use in Cancer Treatment

• Issued by the United States Patent and Trademark Office
• A New Protection Covering OSE-279 Until 2039

Nantes, France – March 21, 2022, 6:00pm CET – OSE Immunotherapeutics SA (ISIN: FR0012127173; Mnemo: OSE) today announces that the United States Patent and Trademark Office (USPTO) has issued a first notice of allowance for a patent application covering OSE-279, an anti-PD1 monoclonal antibody, and its use in cancer treatment. This patent will strengthen the global intellectual property of OSE-279 and will provide the product a protection until 2039.

OSE-279 is a humanized anti-PD1 monoclonal antibody blocking PD-L1 and PD-L2, the ligands of PD1 overexpressed by tumor cells. PD-L1 and PD-L2 are used by tumor cells to escape the immune system. Upregulation of PD-L1 and PD-L2 on tumor cells and other cell types of the tumor microenvironment is a proposed mechanism of tumor immune escape.

OSE-279 is the key anti-PD-1 backbone of BiCKI®-IL-7*, an innovative bifunctional therapy combining anti-PD1 and the cytokine IL-7 and targeting PD1 to sustain exhausted T cell function and to disarm Treg suppressive activity.

Dominique Costantini, Chief Executive Officer of OSE Immunotherapeutics, comments: "We are very pleased with this first notice of allowance for a patent covering OSE-279 in a major territory that simultaneously reinforces the product's intellectual property and its position in our portfolio as an immunotherapy that has the potential to transform the current anti-PD1 standard of care for hard-totreat cancers. We look forward advancing our anti-PD1 backbone development with the Phase 1 clinical trial planned to start in 2022."

* Presentation at the 2022 American Society for Cancer Research (AACR) annual meeting (April 8 – 13): "Anti-PD1/IL7v immunocytokine promotes durable T-cell responses and overcomes anti-PD1 resistance" Session ED015 - Immunocytokines: Strategies for Drug Delivery and Tissue Targeting April 9, 2022, 2:30 PM - 2:50 PM

ABOUT OSE Immunotherapeutics

OSE Immunotherapeutics is an integrated biotechnology company focused on developing and partnering therapies to control the immune system for immuno-oncology and autoimmune diseases. Its balanced first-in-class clinical and preclinical portfolio has a diversified risk profile:

Immuno-Oncology first-in-class products

• Tedopi® (innovative combination of neoepitopes): the company's most advanced product; positive results for Phase 3 trial (Atalante 1) in Non-Small Cell Lung Cancer patients in secondary resistance after checkpoint inhibitor failure.

Other ongoing combination trials sponsored by cooperative clinical research groups in oncology:

Phase 2 in pancreatic cancer (TEDOPaM), sponsor GERCOR.

Phase 2 in ovary cancer, in combination with pembrolizumab (TEDOVA), sponsor ARCAGY-GINECO. Phase 2 in non-small cell lung cancer in combination with nivolumab, sponsor Italian foundation FoRT.

• BI 765063 (OSE-172, anti-SIRPα mAb on CD47/SIRPα pathway): developed in partnership with Boehringer Ingelheim in advanced solid tumors; positive Phase 1 dose escalation results of BI 765063 in monotherapy and in combination with ezabenlimab (PD-1 antagonist); ongoing expansion Phase 1.
• OSE-279, anti-PD1 advanced preclinical stage.
• BiCKI®: bispecific fusion protein platform built on the key backbone component of anti-PD1 combined with a new immunotherapy target (for example: BiCKI®-IL7, preclinical stage) to increase anti-tumor efficacy.

Immunity & Inflammation first-in-class products

• OSE-127/S95011 (humanized monoclonal antibody antagonist of IL-7 receptor): developed in partnership with Servier; positive Phase 1 results; ongoing Phase 2 in ulcerative colitis (sponsor OSE) and ongoing Phase 2a in Sjögren's syndrome (sponsor Servier).
• FR104 (anti-CD28 monoclonal antibody): licensing partnership agreement with Veloxis Pharmaceuticals, Inc. in transplantation; ongoing Phase 1/2 in renal transplant (sponsored by the Nantes University Hospital); US IND obtained by Veloxis Pharmaceuticals, Inc. for a clinical trial; Phase 2 planned in an autoimmune disease indication.
• OSE-230 (ChemR23 agonist mAb): preclinical stage therapeutic agent with the potential to resolve chronic inflammation by driving affected tissues to tissue integrity.

CoVepiT: a prophylactic second-generation vaccine activating cytotoxic T lymphocytes against COVID-19, developed using optimized epitopes from SARS-CoV2 viral proteins, epitopes non impacted by multi-variants. Shows good tolerance and very good level of T cell immune response. In clinical testing, a long-term memory response was confirmed at 6 months.

For more information: https://ose-immuno.com/en/ Click and follow us on Twitter and LinkedIn

Contacts

OSE Immunotherapeutics Sylvie Détry sylvie.detry@ose-immuno.com +33 153 198 757

Investor Relations

Thomas Guillot thomas.guillot@ose-immuno.com +33 607 380 431

Media

U.S. Media: LifeSci Communications Darren Opland, Ph.D. darren@lifescicomms.com +1 646 627 8387

French Media: FP2COM

Florence Portejoie fportejoie@fp2com.fr +33 607 768 283

Guillaume van Renterghem – LifeSci Advisors gvanrenterghem@lifesciadvisors.com +41 76 735 01 31

Forward-looking statements

This press release contains express or implied information and statements that might be deemed forward-looking information and statements in respect of OSE Immunotherapeutics. They do not constitute historical facts. These information and statements include financial projections that are based upon certain assumptions and assessments made by OSE Immunotherapeutics' management in light of its experience and its perception of historical trends, current economic and industry conditions, expected future developments and other factors they believe to be appropriate.

These forward-looking statements include statements typically using conditional and containing verbs such as "expect", "anticipate", "believe", "target", "plan", or "estimate", their declensions and conjugations and words of similar import. Although the OSE Immunotherapeutics management believes that the forward-looking statements and information are reasonable, the OSE Immunotherapeutics' shareholders and other investors are cautioned that the completion of such expectations is by nature subject to various risks, known or not, and uncertainties which are difficult to predict and generally beyond the control of OSE Immunotherapeutics. These risks could cause actual results and developments to differ materially from those expressed in or implied or projected by the forwardlooking statements. These risks include those discussed or identified in the public filings made by OSE Immunotherapeutics with the AMF. Such forward-looking statements are not guarantees of future performance. This press release includes only summary information and should be read with the OSE Immunotherapeutics Universal Registration Document filed with the AMF on 15 April 2021, including the annual financial report for the fiscal year 2020, available on the OSE Immunotherapeutics' website. Other than as required by applicable law, OSE Immunotherapeutics issues this press release at the date hereof and does not undertake any obligation to update or revise the forwardlooking information or statements.