OSE Immunotherapeutics

Investor Presentation • Sep 20, 2023

OSE Immunotherapeutics Updates on its Research Programs in Presentations Selected for Upcoming International Conferences International CICON Conference (Cancer Immunotherapy Conference) SITC Annual Meeting (Society for Immunotherapy of Cancer) PEGS Europe Summit (Protein & Antibody Engineering Summit)

Nantes, France – September 20, 2023, 7:30am CET – OSE Immunotherapeutics SA (ISIN: FR0012127173; Mnemo: OSE) presents scientific updates in presentations selected for European and American conferences: at the 7 th International Cancer Immunotherapy (CICON) Conference in Milan, Italy (September 20 – 23), at the Society for Immunotherapy of Cancer (SITC) 38th Annual Meeting in San Diego, CA, US (November 1 – 5) and at the 15th Annual Protein & Antibody Engineering Summit (PEGS) Europe Summit in Lisbon, Portugal (November 14 – 16). The communications will feature the latest progress on the Company's research programs in immuno-oncology, namely CLEC-1 (novel myeloid immune checkpoint), CYTOMASK, a new and innovative CIS-demasking cytokine linker technology, BiCKI®-IL-7 (bifunctional therapy targeting PD-1 and IL-7), and Tedopi® (T-cell epitope-based cancer vaccine).

Nicolas Poirier, Chief Executive Officer of OSE Immunotherapeutics, comments: "OSE will be presenting 9 communications at upcoming leading international scientific conferences. We are proud of the achievements from our researcher teams on the advancement of our innovative programmes. We are committed to progressing those programmes with the most relevant academic and/or pharma partners to further clinical stage studies and ultimately bring breakthrough immunotherapies to patients with high unmet needs."

DETAILS OF THE OSE IMMUNOTHERAPEUTICS NEXT PRESENTATION:

CICON23 Seventh "International Cancer Immunotherapy Conference: Translating Science into Survival" SEPTEMBER 20-23, 2023 - MILAN, ITALY

NUMBER	TITLE	SESSION	FIRST AUTHOR
P269	ANTAGONIST ANTIBODIES INHIBITING THE BINDING	POSTER SESSION B	Irène BACELLI
	OF MYELOID CHECKPOINT CLEC-1 TO NOVEL	Friday, Sept. 22
	ENDOGENOUS LIGANDS DEMONSTRATE HIGH ANTI
	TUMOR EFFICACIES IN HUMANIZED PRECLINICAL
	MODELS
P270	CIS-DEMASKING CYTOKINE LINKER TECHNOLOGY	POSTER SESSION A	Caroline MARY
	ALLOWS SELECTIVE CYTOKINE DELIVERY TO	Thursday, Sept. 21
	ACTIVATED IMMUNE CELLS WHILE SPARING OTHERS
	AND PERIPHERAL TOXICITY
P271	ANTI-PD-1/IL-7V IMMUNOCYTOKINE FAVORS	POSTER SESSION B	Aurore MORELLO
	PROLIFERATION & SURVIVAL OF TCF1+ STEM LIKE	Friday, Sept. 22
	MEMORY T CELLS ANDA DURABLE IN VIVO EFFICACY
	IN MONOTHERAPY OR USING COMBINATORIAL
	STRATEGY

ABOUT OSE Immunotherapeutics

OSE Immunotherapeutics is a biotech company dedicated to developing first-in-class assets in immuno-oncology and immuno-inflammation. The Company's current well-balanced first-in-class clinical pipeline includes:

• Tedopi® (immunotherapy activating tumor specific T-cells, off-the-shelf, neoepitope-based): this cancer vaccine is the Company's most advanced product; positive results from the Phase 3 trial (Atalante 1) in Non-Small Cell Lung Cancer patients in secondary resistance after checkpoint inhibitor failure. Other Phase 2 trials, sponsored by clinical oncology groups, of Tedopi® in combination are ongoing in solid tumors.
• OSE-279 (anti-PD1): ongoing Phase 1/2 in solid tumors or lymphomas (first patient included). OSE-279 is the backbone therapy of the BiCKI® platform.
• OSE-127 lusvertikimab (humanized monoclonal antibody antagonist of IL-7 receptor); ongoing Phase 2 in Ulcerative Colitis (sponsor OSE Immunotherapeutics); ongoing preclinical research in leukemia (OSE Immunotherapeutics).
• FR-104/VEL-101 (anti-CD28 monoclonal antibody): developed in partnership with Veloxis Pharmaceuticals, Inc. in transplantation; ongoing Phase 1/2 in renal transplant (sponsor Nantes University Hospital); Phase 1 ongoing in the US (sponsor Veloxis Pharmaceuticals, Inc.).
• OSE-172/BI 765063 (anti-SIRPα monoclonal antibody on CD47/SIRPα pathway) developed in partnership with Boehringer Ingelheim in advanced solid tumors; positive Phase 1 dose escalation results in monotherapy and in combination, in particular with anti-PD-1 antibody ezabenlimab; international Phase 1b ongoing clinical trial in combination with ezabenlimab alone or with other drugs in patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) and hepatocellular carcinoma (HCC).

OSE Immunotherapeutics expects to generate further significant value from its two proprietary drug discovery platforms, which are central to its ambitious goal to deliver next-generation first-in-class immunotherapies:

• BiCKI® platform focused on immuno-oncology (IO) is a bispecific fusion protein platform built on the key backbone component of anti-PD1 combined with a new immunotherapy target to increase anti-tumor efficacy. BiCKI-IL-7 is the most advanced BiCKI® candidate targeting anti-PD1xIL-7.
• Myeloid platform focused on optimizing the therapeutic potential of myeloid cells in IO and immuno-inflammation (I&I). OSE-230 (ChemR23 agonist mAb) is the most advanced candidate generated by the platform, with the potential to resolve chronic inflammation by driving affected tissues to tissue integrity.

Additional information about OSE Immunotherapeutics assets is available on the Company's website: www.ose-immuno.com Click and follow us on Twitter and LinkedIn

French Media: FP2COM Florence Portejoie fportejoie@fp2com.fr +33 6 07 768 283

Contacts OSE Immunotherapeutics Sylvie Détry sylvie.detry@ose-immuno.com

Nicolas Poirier Chief Executive Officer nicolas.poirier@ose-immuno.com

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 May 2, 2023, including the annual financial report for the fiscal year 2022, 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.