Tocagen’s lead product, which has recently received Breakthrough Therapy Designation from U.S. FDA for the treatment of recurrent high grade glioma (HGG) and Priority Medicines (PRIME) designation from the European Medicines Agency for the treatment of HGG, involves two discrete steps. First, an investigational virus called Toca 511, which carries a therapeutic gene is injected into the residual tumor in the resection cavity wall immediately following surgical resection, or administered intravenously to patients with metastatic cancer. The virus is designed to integrate into the DNA of dividing cancer cells, which then serve as “factories“ for producing additional viruses. These new virus particles are then designed to spread to neighboring cancer cells, repeating the process and enabling long-term presence of the therapeutic gene within the tumor. In the second step, patients take an investigational oral medication called Toca FC, which is designed to be activated only within infected cancer cells by expression of the therapeutic gene.
After developing a production process in-house, Tocagen needed a leader in the contract manufacturing of viral vaccines and gene therapy drug products to help them turn its innovative science into a viable, scalable approach that could potentially benefit many patients. Manufacturing viruses for clinical trial supply and potentially commercial supply requires the ability to robustly scale production beyond what is required for earlier stages of clinical research.