FibroBiologics, Inc. has announced that the European Patent Office has granted European Patent “Fibroblast Delivery of Tumor Inhibitory Agents.”
The patent covers methods of preparing fibroblasts as anti-cancer delivery compositions by modifying the cells to improve their ability to home to cancer cells and loading them with one or more tumour inhibitory agents, including an oncolytic virus.
Cancer is still one of the most difficult diseases in medicine. Many of the most promising anti-cancer agents, including oncolytic viruses, cytokines, and suicide genes, do their best work inside a tumour. The hard part is getting enough of them there without harming healthy tissue. Fibroblasts have a natural tendency to migrate toward tumours, where they are recruited into the surrounding stroma. The patent builds on that tendency and turns the fibroblast into a delivery vehicle.
The patent describes methods in which fibroblasts are modified to enhance their homing activity toward cancer cells or cancerous tissue. The claimed tumour inhibitory agent comprises an oncolytic virus, such as vaccinia virus. In data described in the patent, fibroblasts carrying Newcastle disease virus significantly inhibited tumour growth in a mouse melanoma model, while the virus given on its own, even at high doses, did not affect tumour growth.
The independent claim covers the core method of preparing tumour-homing fibroblasts loaded with an oncolytic virus and conditioned under hypoxia, whether the homing step is performed before, after, or at the same time as the loading step. Other claims add specific homing receptors (CXCR4, CXCL16, and CCL9), vaccinia virus as the oncolytic virus, and additional payloads delivered by vector, including TNF-alpha, TRAIL, suicide genes, the interleukins IL-2, IL-12, IL-18, and IL-23, interferons, and bispecific antibodies.
Additional claims cover modified fibroblasts for use in treating cancer in individuals who have cancer or are at risk for it, alongside surgery, chemotherapy, radiation, hormone therapy, or immunotherapy. The patent protects the engineered cells as they would be used in a patient, not only the way they are made.
“We filed the first application behind this patent when very few people were thinking about fibroblasts as a way to carry a cancer-killing virus into a tumour,” said Pete O’Heeron, founder and CEO of FibroBiologics.
“Fibroblasts are abundant, they are easy to grow, and they already know how to find a tumour. Our job is to give them something useful to carry when they get there. This patent gives us a long runway in Europe to do that work. Cancer is a long game, and we are building for it.”
Fibroblasts are the most common cell type found in connective tissue and play a central role in tissue repair. Tumours actively recruit fibroblasts into the surrounding stroma, and FibroBiologics’ patented approach puts that behaviour to work. The cells are modified in culture to strengthen their homing activity toward cancer cells, conditioned under hypoxia, and loaded with one or more tumour inhibitory agents, such as an oncolytic virus or a vector encoding an anti-cancer protein.
Once administered, the fibroblasts are intended to carry their payload into the tumour and release it where it is needed, with the goal of concentrating the treatment at the cancer and limiting exposure to healthy tissue.


