€8 Million Horizon Europe Grant Supports Clinical Development of Theolytics Oncolytic Virus Therapy for Advanced Ovarian Cancer

€8 Million Horizon Europe Grant Supports Clinical Development of Theolytics Oncolytic Virus Therapy for Advanced Ovarian Cancer

(IN BRIEF) Scientists at the Institute of Cancer Research in London are contributing to an international clinical trial evaluating THEO-260, an experimental oncolytic immunotherapy designed to treat platinum-resistant ovarian cancer. The trial, known as OCTOPOD-IV, is being supported by €8 million in Horizon Europe funding awarded to biotechnology company Theolytics to expand the study. THEO-260 uses a genetically engineered virus that infects and destroys cancer cells while stimulating the immune system to recognise the tumour. The therapy also targets cancer-associated fibroblasts, supportive cells within tumours that help protect cancer from immune attack. Researchers at the Institute of Cancer Research will conduct detailed translational analyses to understand how the treatment works in patients and identify biomarkers that could guide further development. The international collaboration includes leading cancer centres in Spain and Canada, and the trial will evaluate safety, tolerability and early signs of effectiveness in patients with advanced ovarian cancer who have limited treatment options. Recruitment has already begun in the UK and Spain, while a related study in the United States is exploring a different method of delivering the therapy. The research reflects ongoing efforts to develop innovative immunotherapies capable of overcoming resistance in difficult-to-treat cancers.

(PRESS RELEASE) LONDON, 13-Mar-2026 — /EuropaWire/ — The Institute of Cancer Research is participating in an international clinical study exploring a new immunotherapy approach aimed at treating advanced ovarian cancer, a disease with limited treatment options once it becomes resistant to chemotherapy.

The programme centres on THEO-260, an experimental therapy developed by Theolytics. The company has been awarded €8 million in research funding through the Horizon Europe, subject to final negotiations, to support the expansion of the OCTOPOD-IV Phase IIa clinical trial.

The trial will focus initially on platinum-resistant ovarian cancer, one of the most difficult forms of the disease to treat. Researchers hope the new therapy could offer an alternative approach for patients whose tumours no longer respond to standard chemotherapy.

As part of the international collaboration, scientists at the Institute of Cancer Research will lead important translational research studies designed to better understand how the treatment works in patients. These analyses will involve examining tumour tissue and blood samples to identify biological markers and immune responses that could help guide future development of the therapy.

The treatment itself belongs to a class known as oncolytic immunotherapies. These therapies use specially engineered viruses that selectively infect cancer cells. Once inside the tumour, the virus can kill cancer cells directly while also stimulating the immune system to recognise and attack the disease.

THEO-260 has been designed with an additional mechanism intended to target cancer-associated fibroblasts, supportive cells found within many tumours that help cancer grow and shield it from immune attack. By disrupting both tumour cells and the surrounding fibroblast network, researchers believe the therapy could make the cancer more vulnerable to immune responses.

The Institute of Cancer Research team involved in the project is led by Alan Melcher. His group will analyse biological samples collected during the study to investigate how the treatment interacts with the immune system and why some patients may respond better than others.

The OCTOPOD-IV programme brings together several major cancer research institutions from different countries. Alongside the Institute of Cancer Research, participating centres include Cancer Center Clínica Universidad de Navarra, Catalan Institute of Oncology, and Princess Margaret Cancer Centre in Canada.

Platinum-resistant ovarian cancer represents a major clinical challenge. When tumours stop responding to chemotherapy, treatment choices become limited and survival prospects are often poor. Researchers involved in the study hope that therapies using novel biological mechanisms may open new treatment pathways.

The OCTOPOD-IV study marks the first clinical testing of THEO-260 in patients. The trial will assess the treatment’s safety profile, evaluate how well patients tolerate the therapy, and look for early indications that it may reduce tumour size or slow disease progression. The research will also generate detailed immune and biological data to guide the next stages of clinical development.

Patient recruitment for the trial has already begun at sites in the United Kingdom and Spain, with additional international centres expected to join as the programme expands. In parallel, a related clinical study is underway in the United States, examining the delivery of the therapy directly into the abdominal cavity.

The Institute of Cancer Research has a long track record in advancing oncolytic virus therapies and cancer immunotherapy. Research led by Professor Melcher has helped demonstrate how certain viruses can trigger strong immune responses against tumours and has contributed to early clinical trials evaluating viral-based cancer treatments. This work has also supported the creation of the institute’s Centre for Immunotherapy of Cancer, which focuses on accelerating the development of innovative immune-based therapies.

Professor Melcher noted that therapies capable of targeting both tumour cells and their protective microenvironment while simultaneously activating the immune system could represent a significant advance for patients with advanced solid cancers. The research team aims to generate critical biological insights that will help determine the treatment’s potential and guide its future development.

Dr. Margaret Duffy said the funding award recognises the scientific potential of THEO-260 and reflects the collaborative efforts of the biotechnology company and its international clinical research partners. The study integrates extensive translational analyses into its design to better understand the therapy’s mechanism of action and support the next stage of development aimed at delivering meaningful improvements for cancer patients.

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SOURCE: The Institute of Cancer Research