Company Overview - OSE Immunotherapeutics is a biotech company focused on developing first-in-class assets in immuno-oncology (IO) and immuno-inflammation (I&I) to meet unmet patient needs [3] - The company collaborates with leading academic institutions and biopharmaceutical companies to create transformative medicines for serious diseases [3] Recent Developments - OSE Immunotherapeutics has launched its inaugural Newsletter aimed at individual shareholders and investors, marking the 10th anniversary of its listing on Euronext Paris [2] - The Newsletter will provide updates on company developments, insights into team efforts, and deeper discussions on topics typically covered in press releases [2] Communication Strategy - The Newsletter will be published regularly in both French and English and will be accessible in the "Investors" section of the OSE Immunotherapeutics website [2] - This initiative is intended to enhance communication with individual shareholders and express appreciation for their continued support [2]

Half-Year Report on Liquidity Contract with Invest Securities NANTES, France - July 16, 2025, 6:00pm CET – Under the liquidity contract entrusted by OSE Immunotherapeutics to Invest Securities, the following assets were recorded on the liquidity account as of June 30, 2025: As a reminder, at December 31, 2024, the following assets were recorded on the liquidity account: Forward-looking statements This press release contains express or implied information and statements that might be deemed forward- looking ...

Group 1 - OSE Immunotherapeutics has published its inaugural Letter to Shareholders, highlighting key achievements, growth strategy foundations, and future perspectives [1] - The company is focused on developing first-in-class assets in immuno-oncology and immuno-inflammation to meet unmet patient needs [2] - OSE Immunotherapeutics collaborates with leading academic institutions and biopharmaceutical companies to develop transformative medicines for serious diseases [2] Group 2 - The company is headquartered between Nantes and Paris and is listed on Euronext [2] - Additional information about the company's assets can be found on its website [3]

OSE Immunotherapeutics provides an update on ongoing proceedings Nantes, June 25th, 2025, 8:00 a.m. - OSE Immunotherapeutics SA (ISIN: FR0012127173; Mnemo: OSE), announces that, following the hearing on June 24th, 2025, regarding the request to retract the June 10th, 2025 order by the President of the Nantes Commercial Court, who authorized the postponement of the annual shareholders’ meeting of OSE, the deliberation is expected to occur on Tuesday, July 1st, 2025. OSE Immunotherapeutics will keep the marke ...

ADJOURNMENT OF THE GENERAL MEETING INITALLY CONVENED ON JUNE 25, 2025 NANTES, France, June 11, 6:30 PM – OSE Immunotherapeutics SA (ISIN: FR0012127173; Mnemo: OSE), announces the cancellation of the convening of the mixed General Meeting initially scheduled for June 25, 2025 (the « General Meeting ») to clarify the situation. The Board of Directors will convene a new General Meeting within the allotted time frame. Following the publication on June 3, 2025, of a concerted declaration on the website of the Au ...

Core Points - OSE Immunotherapeutics has requested an extension for the Combined General Meeting scheduled for June 25, 2025, to ensure a regular and transparent process for shareholders [1][2][6] - The request is in response to shareholder concerns regarding the timely communication of resolutions aimed at changing the Board of Directors' composition [2][3] - The resolutions presented by a group of shareholders acting in concert have been renumbered from n°35 to 44 to A to K, with the content remaining unchanged [4] Company Information - OSE Immunotherapeutics is a biotech company focused on developing first-in-class assets in immuno-oncology and immuno-inflammation [8] - The company collaborates with leading academic institutions and biopharmaceutical companies to develop transformative medicines for serious diseases [8] - OSE Immunotherapeutics is based in Nantes and Paris and is listed on Euronext [8]

Core Insights - OSE Immunotherapeutics provided clinical updates on its neo-epitope-based cancer vaccine Tedopi® for pancreatic cancer and non-small cell lung cancer (NSCLC) at the ASCO Annual Meeting, highlighting promising results in ongoing trials [2][3][8]. Company Overview - OSE Immunotherapeutics is a biotech company focused on developing innovative immuno-oncology and immuno-inflammation therapies to meet unmet patient needs [13]. - The company is based in Nantes and Paris and is listed on Euronext [13]. Clinical Trial Updates - The TEDOPaM trial, a Phase 2 study, demonstrated a 12-month overall survival (OS) rate of 65% in patients receiving Tedopi® combined with FOLFIRI chemotherapy, meeting its primary endpoint [6][14]. - The trial enrolled 107 patients, with a median follow-up of 21 months, and reported minimal toxicity associated with Tedopi® [6][14]. - Two complete responses were observed in the experimental arm, while no complete responses were noted in the control arm [14]. Pancreatic Cancer Insights - Pancreatic cancer is a highly aggressive disease, with a five-year survival rate of only 10% globally, and it is projected that new cases will increase by 95.4% by 2050 [10]. - Surgical resection is only feasible for 15-20% of patients at diagnosis, emphasizing the need for effective systemic therapies [11]. NSCLC Developments - The ARTEMIA Phase 3 trial is ongoing, aiming to evaluate Tedopi® as a second-line treatment for HLA-A2 positive NSCLC patients with secondary resistance to anti-PD-(L)1 immunotherapy [9]. - The trial is being conducted across 14 countries and aims to enroll 363 patients [9].

Core Viewpoint - OSE Immunotherapeutics announced that its partner Boehringer Ingelheim will present early clinical data on SIRPα blockade at the ASCO 2025 Annual Meeting, highlighting the potential of their monoclonal antibodies in cancer therapy [2][5]. Company Overview - OSE Immunotherapeutics is a biotech company focused on developing first-in-class assets in immuno-oncology and immuno-inflammation, aiming to address unmet patient needs [10]. - The company collaborates with leading academic institutions and biopharmaceutical companies to bring transformative medicines to market [10]. Clinical Trials and Results - In a Phase 1b study, Boehringer's SIRPα monoclonal antibody, BI 765063, showed a manageable safety profile and preliminary signs of immune activation and anti-tumor activity when combined with PD-1 inhibitor ezabenlimab and cetuximab in patients with recurrent/metastatic head and neck squamous cell carcinoma [3][8]. - Another open-label Phase I trial demonstrated that the next-generation SIRPα monoclonal antibody, BI 770371, was well tolerated both alone and in combination with ezabenlimab in patients with advanced solid tumors, with no dose-limiting toxicities reported [4][8]. Future Development - Boehringer Ingelheim will advance the next-generation SIRPα inhibitor BI 770371 into a Phase 1b study, indicating ongoing commitment to developing innovative cancer therapies [6][8]. - The dual activation strategy of SIRPα blockade paired with PD-1 inhibition is viewed as a promising approach to enhance anti-tumor responses [5]. Presentation Details - The presentations at ASCO 2025 will include: - Title: An Open-Label, Phase Ib Trial of the SIRPα Inhibitor BI 765063 in Combination with the PD-1 Inhibitor Ezabenlimab and Cetuximab in Patients with HNSCC [7] - Title: An Open-label, Phase I Trial of the SIRPα Monoclonal Antibody, BI 770371, Alone and in Combination with the PD-1 Inhibitor Ezabenlimab in Patients with Advanced Solid Tumors [7].

OSE Immunotherapeutics Announces Strategic Collaboration to Pioneer Novel mRNA Technologies OSE Immunotherapeutics to lead French consortium with Inside Therapeutics and MiNT Laboratory (University of Angers) secures €1.3 million in funding from Bpifrance and Région Pays de la Loire NANTES, France – May 21, 2025, 6:00pm CET - OSE Immunotherapeutics SA (ISIN: FR0012127173; Mnemo: OSE), today announces a strategic collaboration with Angoulême/Bordeaux- based Inside Therapeutics and Angers-based MiNT Laborator ...

Core Insights - OSE Immunotherapeutics announced that over 90% of ulcerative colitis patients who responded to Lusvertikimab maintained symptomatic remission for an additional 24 weeks [2][4][15] - The open-label extension of the Phase 2 CoTikiS study demonstrated a significant improvement in remission rates, with 61% of previously non-responding participants achieving remission after further treatment [3][5][15] - Lusvertikimab showed a favorable safety profile throughout the study, with no increased rates of infection reported [4][15] Summary by Sections Study Findings - The Phase 2 CoTikiS study's open-label extension revealed that 89% of participants continued into the extension period, and 87% completed it [4][9] - Symptomatic remission rates improved across all dose groups during the extension period, indicating a deepening of treatment efficacy [5][9] - Participants receiving the 850 mg dose showed plateaued remission rates after Week 14, while those on the 450 mg dose continued to improve through Week 34 [9][15] Clinical Implications - The findings suggest Lusvertikimab's potential as a monotherapy for ulcerative colitis, addressing a significant unmet need in symptom management and patient quality of life [5][6] - The study results challenge the typical therapeutic ceiling, where only 25-30% of patients achieve and maintain remission with existing treatments [5][6] Future Development - The complete CoTikiS results bolster confidence in Lusvertikimab's novel mechanism of action and its potential application in other chronic autoimmune and inflammatory diseases [6][8] - The study supports the progression of Lusvertikimab's development towards a long-acting therapy aimed at treating underlying disease pathophysiology [6][8]