· 9 of 10 patients at the highest dose remained free from peritoneal recurrence
at 24 months at the recommended dose

Oslo, Norway, 17 February 2026 - Oncoinvent (OSE: ONCIN), a biotech developing a
receptor-independent alpha radiopharmaceutical to eradicate cancer cells in the
abdominal cavity after surgery with a single, targeted dose, today announced
that it will present final 24-month results from its RAD-18-001 Phase 1 study of
Radspherin[®] after cytoreductive surgery in patients with platinum-sensitive
epithelial ovarian cancer and peritoneal recurrence at the European Society of
Gynaecological Oncology (ESGO) 2026
Congress (https://congress.esgo.org/?_gl=1%2Audu99c%2A_up%2AMQ..%2A_gs%2AMQ..&gc
l
id=CjwKCAiA4KfLBhB0EiwAUY7GAWzyxvfm3wR5MBPHP
-ALs2dtEV8L43vHiGP8krb497Cr3ZB0AStdfhoCNxgQAvD_BwE&gbraid=0AAAAA
-XVOPX3Lel_7jBh7FnpAm75vtUTB), taking place in Copenhagen, Denmark, from 26-28
February 2026.

Radspherin[®] is an intraperitoneal alpha-emitting therapy ([224]Ra-labeled
microparticles), targeting remaining cancer cells while sparing healthy tissue
within the peritoneal cavity to address microscopic residual disease following
cytoreductive surgery, to prevent recurrence and enhance long-term patient
outcomes.

The poster presentation, titled 'Safety and efficacy results from a phase 1
study of intraperitoneal alpha-emitting radium-224 labelled microparticles after
cytoreductive surgery in patients with peritoneal recurrence of platinum
-sensitive epithelial ovarian cancer,' will share final 24-month data from the
Phase 1 study detailing:

  · 21 patients enrolled across dose levels with a favourable safety profile and
no dose-limiting toxicities observed
  · No grade ?3 adverse events considered related to Radspherin[®]
  · Recommended dose selected at 7 MBq following dose escalation
  · Durable local disease control signal at 24 months: only 1 of 10 patients
treated at the recommended dose  experienced peritoneal recurrence

"We are pleased to present our Phase 1 data at the ESGO 27th Annual Meeting, an
important forum for sharing findings with the international gynecologic oncology
community. These encouraging data reflect the collaborative efforts of the study
team and the potential of Radspherin[®] to address a patient population with
high risk of peritoneal recurrence and poor prognosis," said Yun Wang, MD, PhD,
Department for Cancer Surgery, Section for Gynecological Oncology, The Norwegian
Radium Hospital, Oslo University Hospital, principal investigator in the RAD-18
-001 trial.

Chief Medical Offer Kari Myren at Oncoinvent added, "We remain committed to
advancing Radspherin[®] in the Phase 2 trial and to further evaluating its
potential to benefit patients with ovarian cancer."

Details of the presentation are as follows:

Poster title: Safety and efficacy results from a phase 1 study of
intraperitoneal alpha-emitting radium-224 labelled microparticles after
cytoreductive surgery in patients with peritoneal recurrence of platinum
-sensitive epithelial ovarian cancer
Presenter: Yun Wang, Department of Surgical Oncology Section of Gynaecological
Cancer, Norwegian Radium Hospital, Oslo University Hospital
Authors: Y. Wang[1],[ ]E. Van Nieuwenhuysen[2], L. Chiva[3], E. Chacon[4], M-E.
Revheim[1,5], CM. Deroose[2], L. Sancho[3], JJ. Rosales Castillo[4], A-K.
Aksnes[6], K. Myren[6], I. Vergote[2], ØS. Bruland[1,5]
Session title: Poster walk
Session date and time: 27 February 2026, 17:20-18:20 CET
Location: Exhibition
Abstract ID: 938

Abstracts are available on the ESGO program guide
here (https://congress.esgo.org/), and the poster once presented will be
available at Oncoinvent's website
here (https://www.oncoinvent.com/technology/publications-and-posters/).

[1 The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
2 University Hospital Leuven and KU Leuven, Leuven, Belgium
3 Clínica Universidad de Navarra, Madrid, Spain
4 Clínica Universidad de Navarra, Pamplona, Spain
5 University of Oslo, Oslo, Norway
6 Oncoinvent Solutions AS, Oslo, Norway]

***

For further information, please contact:
Øystein Soug, CEO
Email: IR@oncoinvent.com

Optimum Strategic Communications
Zoe Bolt, Elena Bates, Katherine Bliss
+44 (0) 203 882 9621
oncoinvent@optimumcomms.com

About Oncoinvent

Oncoinvent is developing Radspherin[®], a receptor-independent alpha radiation
therapy that leverages the unique anatomy of the abdominal cavity to destroy
residual micrometastases using a single, highly localized dose of alpha
radiation. The initial clinical focus is treatment of ovarian and colorectal
cancer patients after surgical removal of the primary tumor and visible
metastases in the peritoneum, the thin membrane lining the abdominal cavity and
covering the abdominal organs.

This radiopharmaceutical is designed to prevent or delay recurrence in the
peritoneal cavity, keeping patients disease-free for longer than the current
standard of care and thereby also impacting overall survival. It is broadly
applicable to any cancer that spreads to the peritoneum, e.g. ovarian,
colorectal, and gastric cancers. Radspherin stands out for its simplicity,
excellent safety profile, and seamless integration into existing surgical
workflows. Oncoinvent's product is easy to use, avoids systemic delivery and
significant toxicity. It is also differentiated in being simple to manufacture,
scalable, and supply de-risked.

Data from two trials in ovarian (phase 1) and colorectal (phase 1/2a) cancers,
are highly promising, showing an excellent safety profile and meaningful signals
of efficacy. Interim data from an ongoing, randomized, controlled phase 2
ovarian cancer trial is expected in 2026. With cost-effective manufacturing,
blockbuster potential, active pharma partnership momentum, plus strong
endorsements from leading experts, Oncoinvent is built for scale and commercial
success, and is set to become the new standard for post-surgical cancer care.
The Company was founded by the originators of Algeta and Xofigo (acquired by
Bayer).