OSE Immunotherapeutics Reports Positive Topline Results of Combi-TED Phase 2 Randomized Trial with Tedopi® (OSE2101) in metastatic Non-Small Cell Lung Cancer

• Topline results to be presented by Federico Cappuzzo, MD, PhD, on October 25, 2026, at the Annual Meeting of the European Society for Medical Oncology (ESMO) in Madrid
• OSE Immunotherapeutics to host a KOL webcast on November 4, 2026

Nantes, France, October 19, 2026 – 7:30am CEST – OSE Immunotherapeutics SA (ISIN: FR0012127173; Mnemo: OSE), a clinical-stage biotech company dedicated to developing first-in-class therapies in immuno-oncology and immuno-inflammation, today announced the release of the abstract selected for an oral presentation at the upcoming ESMO 2026 Annual Meeting, unveiling topline results from the Combi-TED academic Phase 2 international clinical trial of Tedopi® sponsored by FoRT and evaluating Tedopi® (OSE2101), in combination with either chemotherapy or anti-PD1, as a 2nd line treatment in patients with metastatic Non-Small Cell Lung Cancer (NSCLC).

Federico Cappuzzo, MD, PhD, Director of Medical Oncology at the National Cancer Institute Regina Elena (Rome, Italy) and Lead Investigator of the trial, commented: “The only option we currently have in our practice, for these patients in second line, unfortunately remains docetaxel, which has the toxicity of chemotherapy and a limited efficacy. Tedopi® in monotherapy has already shown signs of superiority compared to docetaxel in terms of efficacy associated with a better safety and tolerability profile; the phase 3 study ARTEMIA, currently underway, was designed specifically to confirm this. In Combi-TED, we almost doubled the survival at one year with Tedopi® combined with either chemotherapy docetaxel or immunotherapy nivolumab, an extremely encouraging result that represents a new step forward in the treatment strategy for patients with progressive NSCLC.”

Combi-TED is an open label, randomized, three-arm Phase 2 study evaluating Tedopi® in combination with docetaxel or the anti-PD1 immune checkpoint inhibitor nivolumab (Opdivo®), or docetaxel alone (reference arm) as second-line treatment in 106 HLA-A2 positive patients with metastatic NSCLC and no evidence of EGFR mutations or ALK or ROS1 rearrangement, after first-line chemo-immunotherapy. The primary endpoint was 1-year Overall Survival (OS) rate. The trial was conducted in 19 sites in France, Italy and Spain. (NCT04884282).

The primary endpoint was met and results showed a statistically significant 1-year OS rate for both combinations of Tedopi® and docetaxel (OS = 47%; p = 0.001) and Tedopi® and nivolumab (OS = 46%; p = 0.002) but not for docetaxel alone (OS = 29%; p = 0.287).

Bayesian statistical analyses suggest a posterior probability >90% of improved 1-year OS versus docetaxel alone for both Tedopi®-based combinations.

Treatment-related adverse events occurred in 89% (Tedopi® + docetaxel), 82% (Tedopi® + nivolumab), and 79% (docetaxel alone) of patients. Drug-related serious adverse events were reported in 17% (Tedopi® + docetaxel), 24% (Tedopi® + nivolumab), and 17% (docetaxel alone) of patients. No unexpected safety signals were observed.

Final results will be presented on October 25, 2026, at the ESMO 2026 Annual Meeting in Madrid by Lead Investigator Federico Cappuzzo, MD, PhD.

In addition, OSE will be hosting a KOL webcast on November 4, 2026, to discuss these results and how Tedopi® could benefit patients affected by NSCLC progressing after 1st line chemo-immunotherapy with key opinion leaders Stephen Liu, MD (MedStar Georgetown University Hospital) and Federico Cappuzzo, MD, PhD (National Cancer Institute Regina Elena, Rome).

Silvia Comis, MD, Chief Clinical and Medical Research Officer, commented: “Tedopi-based combinations are encouraging supporting further evaluation of vaccine-based immunotherapy strategies in this setting. A Phase 3 registrational study of Tedopi monotherapy compared to docetaxel (ARTEMIA) is currently recruiting NSCLC patients with secondary resistance to immunotherapy, with results expected in early 2028.”

KOL Webcast on Wednesday, November 4, 2026
5pm CET / 11am ET

Live in English with optional French subtitles
Link to Webcast: https://bit.ly/3UpDfL8

ABOUT OSE IMMUNOTHERAPEUTICS

OSE Immunotherapeutics is a biotech company dedicated to developing first-in-class assets in immuno-oncology (IO) and immuno-inflammation (I&I) that address the unmet patient needs of today and tomorrow. We partner with leading academic institutions and biopharmaceutical companies in our efforts to develop and bring to the market transformative medicines for people with serious diseases. OSE Immunotherapeutics is based between Nantes and Paris and is listed on Euronext. Additional information about OSE Immunotherapeutics assets is available on the Company’s website: www.ose-immuno.com. Follow us on LinkedIn.

ABOUT FORT

FoRT (Fondazione Ricerca Traslazionale) aims to support oncology research by optimizing available treatments and striving to improve patient life expectancy. Numerous anti-cancer drugs are available in oncology; unfortunately, only a few patients benefit from these treatments, while many experience their side effects. Translational research makes it possible to identify which patients will benefit from a treatment and which will not. Translational research also helps determine the prognostic value of various biological factors, allowing physicians to better predict the progression of the disease. FoRT’s activities include promoting clinical and preclinical studies, supporting scientific initiatives, and disseminating and publishing the resulting scientific data. Furthermore, FoRT seeks to provide concrete assistance to patients in navigating the management of their disease and accessing the best available therapeutic options. More information on www.fondazionefort.org.

Contacts

OSE Immunotherapeutics: investors@ose-immuno.com

FP2COM (Media Relations): Florence Portejoie: fportejoie@fp2com.fr I +33 6 07 768 283
Astr Partners (Investor Relations): Brian Korb: brian.korb@astrpartners.com I +1 917-653-5122

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 considering 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 forward-looking 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 June 4, 2026, including the annual financial report for the fiscal year 2025, 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 forward-looking information or statements.