A team of researchers from the Hospital Sant Joan de Déu Barcelona and the biotechnology company VCN Biosciencies has developed a pioneering treatment based on an oncolytic virus that has enabled a child to overcome retinal cancer. The treatment has managed to prevent the boy, who had already lost one eye as a result of retinal cancer, from losing the other and becoming completely blind.
Thus, the patient, who traveled from Venezuela to Barcelona to receive the treatment, is free of the disease and maintains his visual acuity, so that he can carry out his life with total normality.
What does the treatment consist of?
The treatment, administered within the framework of a clinical trial, consists of an injection with a genetically modified virus. The virus is injected into the eye affected by the tumor in order to select, attack and destroy the cancer cells.
The child was diagnosed with retinal cancer, known as retinoblastoma, which affected both eyes. At the age of two, he lost one eye to the disease and traveled to Barcelona to receive treatment at the Hospital Sant Joan de Déu to save his other eye and maintain his vision.
The team of specialists from the intraocular tumor unit who treated the boy managed to inactivate the tumor through intra-arterial chemotherapy treatment. However, after eight months he had a relapse and the hospital team found that the tumor no longer responded to conventional treatments. The team then made a proposal to the family to participate in a clinical trial to evaluate the safety and efficacy of the oncolytic virus VCN-01 against chemotherapy-resistant retinal cancer.
What is the oncolytic virus?
The treatment received a genetic modification of the adenovirus. Adenovirus is a common virus that usually causes cold symptoms, and is currently being used by international researchers to develop a vaccine against COVID-19. This virus has been modified in the VCN Biosciences laboratory so that it can identify, infect and multiply in cancer cells. This allows the oncolytic virus to select, attack and destroy cancer cells, leaving healthy cells intact.
This case has demonstrated the therapeutic efficacy of the oncolytic virus for the treatment of retinal cancer in children. However, the clinical trial requires more patients to confirm that the dose administered is correct to ensure efficacy.
Retinoblastoma: the most common eye tumor in children
Every year, more than 8,000 children are diagnosed with retinoblastoma worldwide, making it the most common eye tumor in children. The patients who are candidates to participate in the clinical trial are children suffering from retinoblastoma who do not respond to conventional treatments.
This cancer originates in the first years of life when the retina develops. Currently, at the Hospital Sant Joan de Déu the first option for children affected by this pathology is treatment with intra-arterial chemotherapy. It consists of introducing a long, thin catheter through the femoral artery, in the groin, and it is guided to the ophthalmic artery in order to locally administer the chemotherapy. In some cases, chemotherapy is also injected into the eye, into the vitreous humor.
Until now, when the tumor did not respond to these conventional treatments, ophthalmologists only had the option of enucleating the affected eye to prevent the cancer from spreading to other organs of the body. However, with the development of this new treatment, it may be possible to overcome the cancer and maintain visual acuity.