Lund, Sweden – May 20, 2026 – BioInvent International AB (“BioInvent”) (Nasdaq Stockholm: BINV), a leader in the discovery of novel immune‑modulatory antibodies, today announced that it will host a virtual key opinion leader (KOL) event on Wednesday, May 27, 2026 at 8:00 AM EDT / 2:00 PM CEST featuring Dmitriy Zamarin MD, PhD (Tisch Cancer Center, Icahn School of Medicine at Mount Sinai), who will join company management to discuss the unmet need and current treatment landscape for ovarian cancer. To register, click here.

The event will provide an overview of BI-1808, which has shown highly encouraging clinical activity both as single agent as well as in combination with pembrolizumab. Earlier disclosed interim data from 21 evaluable patients treated with BI-1808 plus pembrolizumab demonstrated an overall response rate (ORR) approximately three times higher than historically reported for pembrolizumab alone in heavily pretreated ovarian cancer patients.

Agenda
08:00 am | BioInvent, Poised for Growth | Martin Welschof, CEO
08:05 am | Ovarian Cancer Treatment Landscape, Medical Need and Future Treatment of Ovarian Cancer | Dmitriy Zamarin, MD, PhD
08:25 am | BI-1808’s Differentiated Mechanism of Action | Björn Frendéus, CSO
08:30 am | BI-1808 in Ovarian Cancer | Andres McAllister, CMO
08:50 am | Translational Data: Dynamics of Responses | Björn Frendéus, CSO
09:05 am | Market Opportunity for BI-1808 | Sylvie Ryckebusch, CBO
09:15 am | Final Remarks | Martin Welschof, CEO
09:20 am | Live Q&A Session | All presenters

The webcast will be conducted in English and broadcast live. A replay of the webcast and presentation materials will be made available on BioInvent’s website following the event.

This event is the first in a two-part KOL series. A second event taking place on June 11th will focus on BI-1206 and BI-1808 for the treatment of non-Hodgkin's lymphoma and cutaneous T-cell lymphoma, respectively.

About Dmitriy Zamarin MD, PhD
Dmitriy Zamarin MD, PhD is Professor of Oncology, Section Head of Gynecologic Medical Oncology, and co-director of Center of Excellence for Gynecologic Cancers at the Tisch Cancer Center at Icahn School of Medicine at Mount Sinai. Dr. Zamarin obtained his MD and PhD degrees from the Mount Sinai School of Medicine. He completed residency in Internal Medicine at the Mount Sinai Hospital and fellowship in Hematology/Oncology at the Memorial Sloan Kettering Cancer Center. He spent a decade as a faculty and Translational Research Director in Gynecologic Medical Oncology at the Memorial Sloan Kettering Cancer Center before transitioning to his current role in September of 2023. Dr. Zamarin has served as a principal investigator and a translational chair on multiple institutional and cooperative group clinical trials exploring novel immunotherapy combinations in gynecologic cancers and other solid tumors and serves as the translational research co-chair on the NRG Oncology Cervical Cancer committee (NRG is a prominent national cooperative group funded by the National Cancer Institute (NCI) that conducts clinical trials for cancer treatments). In the laboratory, his research is focused on understanding of the mechanisms by which gynecologic cancers are recognized by the immune system and on identification of biomarkers predictive of response and resistance to immunotherapy. His laboratory uses experimental models to explore the mechanisms of tumor-immune system interactions and to develop novel therapeutics, with particular focus on oncolytic viruses, vaccines, and targeted therapies. Dr. Zamarin has received awards and funding from multiple organizations including Damon Runyon Foundation, Ovarian Cancer Research Alliance, Department of Defense, and the National Cancer Institute and is an elected member of the American Society for Clinical Investigation.

About the BI-1808 Phase 2a Study
This Phase 2a trial (NCT04752826) is designed to assess the safety and tolerability of BI-1808 as a single agent (Part A), in combination with pembrolizumab (Part B) and in a triple combination with pembrolizumab and paclitaxel (Part C). The study aims to characterize safety, pharmacokinetics and pharmacodynamics, and assess preliminary antitumor activity by ORR, DoR (duration of response), and progression-free survival (PFS), as measured by RECIST v1.1 and iRECIST.

About BI-1808
The anti-TNFR2 antibody BI-1808 is part of BioInvent’s tumor-associated regulatory T cells (Treg)-targeting program. TNFR2 is particularly upregulated on Tregs of the tumor microenvironment and has been shown to be important for tumor expansion and survival, representing a new and promising target for cancer immunotherapy. BI-1808 is a first-in-class drug candidate in clinical development for the treatment of T-cell lymphoma and solid tumors.

A manuscript detailing the mechanisms of action of the BI-1808 and differentiated BI-1910 anti-TNFR2 antibodies is available on BioRxiv.com, an open-access online repository for yet unpublished research manuscripts (preprints). Both anti-TNFR2 antibodies show potent anti-tumor efficacy across multiple syngeneic mouse tumor models, 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 is a pure agonist antibody that directly co-stimulates T and NK cells through partially FcgR-independent mechanisms.

About BioInvent
BioInvent International AB (Nasdaq Stockholm: BINV) is a clinical-stage biotech company that discovers and develops novel and first-in-class immuno-modulatory 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 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 www.bioinvent.com.

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
www.bioinvent.com