Press Release

Tocagen Expands Toca 5, Phase 2/3 Clinical Trial for Recurrent Brain Cancer, to South Korea

SAN DIEGO – Jan. 13, 2017 — Tocagen Inc., a clinical-stage, cancer-selective gene therapy company, today announced its randomized, controlled Phase 2/3 clinical trial, called Toca 5, is now enrolling patients in South Korea. The trial is ongoing in the United States, Canada and Israel. The study compares a cancer-selective virus, Toca 511 (vocimagene amiretrorepvec), in combination with Toca FC (extended-release 5-fluorocytosine), to standard of care in patients with first or second recurrence of glioblastoma or anaplastic astrocytoma who are undergoing resection.

"Brain tumors are among the deadliest of all cancers and there are very few treatment options available," said Do Hyun Nam, M.D., professor, department of neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, which enrolled the first patient in South Korea. "Data from Phase 1 studies of this investigational agent showed very promising safety, survival and durable tumor response data so we are excited to continue evaluation of this therapy in the Toca 5 trial."

Sin-Soo Jeun, M.D., professor of neurosurgery at Seoul St. Mary's Hospital, is the principal investigator for the Toca 5 clinical trial in South Korea.

The primary endpoint for the Toca 5 clinical trial is overall survival with secondary endpoints including objective response rate. Investigators may choose chemotherapy (lomustine or temozolomide) or antiangiogenic therapy (bevacizumab) for the control arm. More information about the clinical trial can be found at

High grade gliomas are among the most common and aggressive primary brain cancers. The two most common forms of high grade glioma are glioblastoma and anaplastic astrocytoma. Standard treatment for newly diagnosed high grade glioma includes safe surgical removal of as much of the tumor as possible followed by radiation therapy and chemotherapy. Despite these treatments, the tumor typically recurs. Median survival after recurrence is approximately seven to nine months.

A total of 126 patients have been treated in Tocagen's Phase 1, ascending-dose studies. Clinical data were recently published in Science Translational Medicine. In the subset of patients in the higher dose cohorts that mirror the patient population under evaluation in the ongoing Toca 5 trial, a clinical benefit rate of 41.7% was reported at the 21st Annual Scientific Meeting and Education Day of the Society for Neuro-Oncology. This included 3 complete responses, 2 partial responses and 5 patients with stable disease (N=24). All patients with an objective response remain alive and in response. The median duration of response is at least 26.7 months. A summary of clinical data from Tocagen's ongoing Phase 1 clinical trials can be found on Tocagen's website.

About Toca 511 & Toca FC

Tocagen's lead product candidate is a combination of an investigational biologic, Toca 511, and an investigational oral tablet, Toca FC. Toca 511 encodes a prodrug activator enzyme, CD. Its selective delivery to cancer cells means that the infected cancer cells carry the CD gene and produce CD protein. Toca FC is an orally administered, proprietary extended-release formulation of 5-fluorocytosine (5-FC), a prodrug that is inactive as an anti-cancer drug. Within Toca-511-infected cancer cells that are producing CD, Toca 511 is designed to convert Toca FC into the anti-cancer drug, 5-fluorouracil (5-FU) at local high concentrations. In addition to the direct killing of Toca 511-infected cancer cells, 5-FU kills neighboring uninfected cancer cells and immunosuppressive myeloid cells including myeloid derived suppressor cells (MDSCs) and tumor associated macrophages (TAM) in the tumor.

About Tocagen

Tocagen is a clinical-stage, cancer-selective gene therapy company developing first-in-class, broadly applicable product candidates designed to activate a patient's immune system against their own cancer. The company is developing its lead investigational product candidate, Toca 511 (vocimagene amiretrorepvec) & Toca FC (extended-release 5-fluorocytosine), initially for the treatment of recurrent high grade glioma (HGG), a disease with significant unmet medical need. Tocagen has initiated the Phase 2 portion of a randomized, controlled Phase 2/3 clinical trial of Toca 511 & Toca FC in patients with recurrent HGG, which is designed to serve as a potential registrational trial. More information about the clinical trial can be found at Tocagen has initiated a clinical trial of Toca 511 & Toca FC in metastatic cancers, including colorectal, pancreatic, lung, breast, renal and melanoma. Tocagen obtained Fast Track designation from the U.S. Food and Drug Administration for Toca 511 & Toca FC as a treatment of recurrent HGG and Orphan drug designation for the treatment of glioblastoma multiforme (GBM), a subset of HGG. Tocagen has received grant support from leading brain cancer foundations, including Accelerate Brain Cancer Cure (ABC2), National Brain Tumor Society (NBTS), American Brain Tumor Association (ABTA), Musella Foundation and Voices Against Brain Cancer(VABC). For more information, visit or follow @Tocagen.

Media Contact:
Monica May
Canale Communications
(619) 849-5383