BI-1808

Preclinical manuscript that characterizes the mechanism of action, broad antitumor efficacy, and immune-activating properties of BI-1808 and BI-1910 across diverse tumor microenvironments Data demonstrates the ability of the lead anti-TNFR2 antibody BI-1808 to elicit antitumor immunity in CD8+ T cell poorly infiltrated tumors resistant to immune checkpoint blockade BI-1808 is currently being evaluated in ongoing Phase 2a clinical trials with clinical data showing promising activity across both hematologic and solid tumor settings with the potential to become the next standard of care in ovarian cancer LUND, SE / ACCESS Newswire / August 20, 2026 / BioInvent International AB ("BioInvent") (Nasdaq Stockholm:BINV), a leader in the discovery of novel immune-modulatory antibodies, today announced that a preclinical manuscript characterizing the mechanism of action, broad antitumor efficacy, and ability to elicit antitumor immunity of BI-1808 and BI-1910 has been published in Cancer Research , a peer-reviewed journal of the American Association for Cancer Research. The publication is entitled "Ligand-Blocking and Agonist Antibodies Targeting TNFR2 Employ Distinct Modes of Action to Induce Antitumor Immunity" and is available at . "This publication provides a comprehensive mechanistic understanding of how BI-1808 and BI-1910 modulate the tumor microenvironment to drive antitumor immunity. It also highlights BioInvent's leading role in TNFR2 targeting," said Björn Frendéus, Ph.D., Chief Scientific Officer of BioInvent. "The breadth of activity demonstrated across tumor types, notably including poorly CD8+ T cell infiltrated tumors resistant to immune checkpoint blockade, in these preclinical studies is consistent with the clinical signals we are observing with BI-1808 and reinforces our conviction in TNFR2 as a high-value target in cancer immunotherapy." Both anti-TNFR antibodies show potent anti-tumor efficacy across multiple syngeneic tumor models in vivo, can effectively be combined with anti-PD-1, and trigger CD8+ T cell antitumor immunity, albeit by different mechanisms; BI-1808 is a ligand-blocking FcgR-engaging antibody that depletes immunosuppressive Treg cells and reprograms myeloid cells. BI-1910, currently paused due to priority reasons, is a pure agonist antibody that directly co-stimulates T and NK cells through partially FcgR-independent mechanisms. About BI-1808 BI-1808 is a first-in-class drug candidate targeting TNFR2. TNFR2 is upregulated on both immunosuppressive and inflammatory tumor-infiltrating lymphocytes (TILs) and on myeloid cells in the tumor microenvironment, making it a dynamic, promising new target for cancer immunotherapy. BI-1808 is in clinical development for the treatment of T-cell lymphoma and solid tumors. In an ongoing Phase 1/2a study, it has shown both single-agent activity and excellent tolerability, as well as efficacy and a favorable safety pro combination with pembrolizumab, in solid tumors and T-cell lymphomas About BioInvent BioInvent International AB (Nasdaq Stockholm: BINV) is a clinical-stage biotech company that discovers and develops novel and first-in-class immunomodulatory antibodies for cancer therapy, with drug candidates in ongoing clinical programs in Phase 1/2 trials for the treatment of hematological cancer and solid tumors. The Company's validated, proprietary n-CoDeR F.I.R.S.T™ technology platform identifies both targets and the antibodies that bind to them, generating many promising new immune-modulatory candidates to fuel the Company's own clinical development pipeline and providing licensing and partnering opportunities. The Company generates revenues from research collaborations and license agreements with multiple top-tier pharmaceutical companies, as well as from producing antibodies for third parties in the Company's fully integrated manufacturing unit. More information is available at . For further information, please contact: Cecilia Hofvander, VP Investor Relations Phone: +46 (0)46 286 85 50 Email: cecilia.hofvander@bioinvent.com BioInvent International AB (publ) Co. Reg. No.: 556537-7263 Visiting address: Ideongatan 1 Mailing address: 223 70 LUND Phone: +46 (0)46 286 85 50 The press release contains statements about the future, consisting of subjective assumptions and forecasts for future scenarios. Predictions for the future only apply as the date they are made and are, by their very nature, in the same way as research and development work in the biotech segment, associated with risk and uncertainty. With this in mind, the actual outcome may deviate significantly from the scenarios described in this press release. Attachments BioInvent Announces Publication of Preclinical Manuscript on BI-1808 and BI-1910 in Cancer Research SOURCE: BioInvent International View the original press release on ACCESS Newswire

BioInvent International AB has announced that the US Food and Drug Administration (FDA) has granted Fast Track Designation to BI-1808, the company’s first-in-class anti-TNFR2 antibody, for the treatment of ovarian cancer in combination with pembrolizumab. The designation is intended to facilitate the development and regulatory review of BI-1808 for patients with ovarian cancer, an area where significant unmet medical needs remain, particularly among patients whose disease has progressed following platinum-based therapy. Martin Welschof, Chief Executive Officer of BioInvent, said the FDA designation represents an important milestone for BI-1808 and reflects both the unmet need in difficult-to-treat ovarian cancer and the clinical signals generated so far. He noted that data across high-grade serous and clear cell ovarian cancer subtypes support the potential of TNFR2 targeting to enhance the activity of PD-1 inhibitors in tumours where these therapies have historically delivered limited benefit. BI-1808 is designed to target tumour necrosis factor receptor 2 (TNFR2), which is highly expressed on immunosuppressive regulatory T cells (Tregs) within the tumour microenvironment. The antibody is intended to deplete these Tregs while activating myeloid cells and CD8-positive T cells, potentially enhancing anti-tumour immune responses and creating synergy with PD-1 blockade. The company said interim Phase 2a data presented at the ASCO 2026 Congress demonstrated encouraging activity for BI-1808 in combination with pembrolizumab without chemotherapy. In heavily pretreated patients with recurrent ovarian cancer following platinum therapy, the combination achieved a 24 percent confirmed Overall Response Rate (ORR) and a 56percent Disease Control Rate (DCR). Responses were observed across both high-grade serous and clear cell ovarian cancer subtypes. Several patients experienced prolonged disease control, with some responses continuing beyond 10 months. Preliminary analyses indicated a median Progression-Free Survival (mPFS) of 10.3 months. The results are notable given the limited activity historically observed with pembrolizumab monotherapy in this patient population, where the company cited an approximately 8 percent response rate. The ongoing Phase 2a study, registered as NCT04752826, is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary anti-tumour activity of BI-1808 across multiple treatment settings. Part A evaluates BI-1808 as a monotherapy, Part B assesses the combination with pembrolizumab, while Part C evaluates a triple combination of BI-1808, pembrolizumab and paclitaxel. The study is assessing treatment outcomes through measures including overall response rate, duration of response and progression-free survival, using RECIST v1.1 and iRECIST criteria. BioInvent has been collaborating with MSD, known as Merck & Co in the United States and Canada, since August 2021 under a clinical trial collaboration and supply agreement to evaluate BI-1808 in combination with the company’s anti-PD-1 therapy, Keytruda (pembrolizumab). BI-1808 forms part of BioInvent’s tumour-associated Treg-targeting programme. TNFR2 is considered an important target in cancer immunotherapy because of its elevated expression on Tregs in the tumour microenvironment and its role in supporting tumour expansion and survival. The investigational antibody is being evaluated in clinical development for both T-cell lymphomas and solid tumours. BioInvent said BI-1808 has demonstrated single-agent activity and favourable tolerability in an ongoing Phase 2a study, while combination studies with pembrolizumab have generated efficacy and safety signals across solid tumours and T-cell lymphomas. Preclinical research has further supported the mechanism of BI-1808. The antibody is designed as a ligand-blocking, Fc-gamma receptor-engaging therapy that can deplete immunosuppressive Tregs and reprogramme myeloid cells. In preclinical tumour models, BI-1808 demonstrated anti-tumour activity and enhanced responses when combined with anti-PD-1 therapy, with increased CD8-positive T-cell-mediated anti-tumour immunity. BioInvent is a clinical-stage biotechnology company focused on discovering and developing novel immunomodulatory antibodies for cancer treatment. Its pipeline includes first-in-class drug candidates being evaluated in Phase 1/2 clinical programmes for haematological cancers and solid tumours.