Theolytics Advances Novel Oncolytic Immunotherapy THEO-260 in Phase I/IIa Ovarian Cancer Trial
Key Insights
Theolytics (search) is presenting data from the ongoing OCTOPOD-IV Phase I/IIa trial of THEO-260, a novel oncolytic immunotherapy targeting cancer cells and cancer-associated fibroblasts (search) in ovarian cancer (search) patients.
The first-in-human trial evaluates intravenous delivery of THEO-260 in patients with high-grade serous or endometrioid ovarian cancer (search), with recruitment ongoing at UK sites and international expansion planned.
A second US trial (OCTOPOD-IP) investigating intraperitoneal delivery has been initiated in collaboration with MD Anderson Cancer Center, addressing the significant unmet need in platinum-resistant ovarian cancer (search).
Theolytics (search), a clinical-stage biotechnology company developing next-generation oncolytic immunotherapies, is advancing its lead candidate THEO-260 through Phase I/IIa clinical trials for ovarian cancer (search) treatment. The company will present trial progress data at the European Society for Medical Oncology (ESMO) Congress in Berlin from October 17-21, 2025.
Novel Mechanism Targets Stromal-Rich Tumor Environment
THEO-260 represents a differentiated approach to ovarian cancer (search) treatment, specifically designed to target the complex tumor microenvironment characteristic of this disease. According to Theolytics (search), the therapy effectively targets both cancer cells and cancer-associated fibroblasts (search) (CAFs (search)) while inducing immune activation in stromal-rich tumors.
"THEO-260's differentiated mechanism of action in targeting and eliminating ovarian patient cancer cells and cancer-associated fibroblasts (search), whilst triggering immunogenic cell death and promoting T-cell activation, we hope that we can deliver a therapy that transforms outcomes for women with this devastating disease," said Dr. Matilde Saggese, MD, MD (Res), Theolytics (search)' Chief Medical Officer.
The therapeutic approach addresses a critical challenge in ovarian cancer (search) treatment, where the tumor microenvironment can be comprised of up to 60% cancer-associated fibroblasts (search), contributing to immune suppression and treatment resistance.
Dual Clinical Trial Strategy
The OCTOPOD-IV trial (NCT06618235) represents a first-in-human, multi-center study designed to assess safety, tolerability, and preliminary efficacy of THEO-260 administered intravenously in patients with high-grade serous ovarian or endometrioid cancer. The trial aims to determine the recommended Phase II dose and demonstrate the therapy's CAF-lytic mechanism of action through comprehensive biomarker analysis.
Recruitment at UK clinical sites is currently ongoing, with planned expansion to international sites including Spain and Canada. The company has also initiated a second clinical trial, OCTOPOD-IP (NCT07211659), in collaboration with The University of Texas MD Anderson Cancer Center, investigating intraperitoneal delivery of THEO-260 to advanced ovarian cancer (search) patients.
Addressing Treatment-Resistant Disease
The clinical development program targets a significant unmet medical need in ovarian cancer (search) care. Patients with epithelial ovarian cancer (search) almost invariably develop platinum-resistant disease (search), which carries a very poor prognosis. Treatment in this setting presents considerable challenges due to the complexity of the tumor microenvironment, and most immunotherapies, including checkpoint blockade, have not proven effective in this indication.
The immune-suppressed and stromal-rich nature of the ovarian cancer (search) tumor microenvironment may explain the limited success of conventional immunotherapies. THEO-260's approach of specifically targeting this stromal component while promoting immune activation represents a novel strategy for overcoming these treatment barriers.
Preclinical Foundation
In preclinical studies, THEO-260 demonstrated the ability to kill both cancer cells and cancer-associated fibroblasts (search), trigger immunogenic cell death, and promote T-cell activation. The therapy showed effective killing of cancer cells and CAFs (search) while inducing immune activation in advanced preclinical models, including extensive panels of ovarian cancer (search) patient samples.
Theolytics (search), founded in 2017 and headquartered in Oxford, UK, has developed a proprietary approach to create efficacious, targeted adenoviral candidates suitable for direct and systemic intravenous delivery. The company is backed by international life sciences investors including Taiho Ventures, M Ventures, Oxford Science Enterprises, Epidarex Capital, Sound Bioventures, BGF, and Oxford University Innovation.