Tocagen Appoints David R. Parkinson, M.D., to the Board of Directors

Executive Previously Led Oncology Clinical Development at Amgen and Novartis, Drug Development Activities at the National Cancer Institute

SAN DIEGO – May 5, 2015 — Tocagen Inc. a clinical-stage immuno-oncology company, today announced that David R. Parkinson, M.D., a venture partner at New Enterprise Associates (NEA), has been appointed to the board of directors of Tocagen. Dr. Parkinson has more than twenty years of experience in oncology clinical development, including leading clinical activities at Amgen and Novartis that resulted in global approvals of the cancer therapeutics Gleevec®, Femara®, Zometa®, Kepivance® and Vectibix®, as well as serving as chief of the Investigational Drug Branch at the National Cancer Institute.

“I have had the pleasure of working with David on several occasions, and I welcome the opportunity to work with him again as I have seen firsthand his tremendous depth of expertise in oncology drug development, ranging from late-stage clinical and registration activities to preclinical drug development,” said Faheem Hasnain, chairman of the board of directors of Tocagen and president and chief executive officer of Receptos, Inc. “As Tocagen continues to advance its lead product into pivotal trials and develop its immuno-oncology platform, David’s insights from years of experience in drug development and strategic partnering will be an invaluable resource to the company.”

Dr. Parkinson added, “Tocagen’s technology, which leverages retroviral replicating vectors to selectively infect cancer cells, break immune tolerance and persistently activate the immune system against multiple tumor associated antigens, is a highly differentiated approach to treating cancer. I look forward to working with the Tocagen team to advance this novel immuno-oncology technology, which holds much promise as a treatment for patients with brain cancer and also has the potential to be broadly applicable across other cancers.”

Among other prior roles, Dr. Parkinson was vice president of oncology development at Amgen, vice president of global clinical oncology development at Novartis and senior vice president at Biogen Idec, leading oncology research and development. Dr. Parkinson presently serves on the board of directors of Threshold Pharmaceuticals and Cerulean Pharma Inc. and previously served on the board of directors of Facet Biotech, acquired by Abbott, and Ambit Biosciences Corporation, acquired by Daiichi Sankyo. Prior to joining industry, Dr. Parkinson worked at the National Cancer Institute for almost a decade, including serving as chief of the Investigational Drug Branch. He has also served as the chairman of the FDA Biologics Advisory Committee.

About Toca 511 & Toca FC
Toca 511 & Toca FC is a combination treatment being investigated in four clinical trials in patients with recurrent high grade glioma, including glioblastoma. A pivotal Phase 2/3 study in patients with recurrent glioblastoma or anaplastic astrocytoma (the “Toca 5” study) is anticipated to initiate in 2015. The combination of Toca 511 & Toca FC is designed to break immune tolerance to the tumor using a combination of mechanisms. Toca 511, a retroviral replicating vector (RRV), delivers a prodrug-activating gene selectively to cancer cells. Then the prodrug-activating enzyme produced in the cancer cell converts orally administered Toca FC, an investigational extended-release formulation of 5-fluorocytosine (5-FC), into a powerful antimetabolite, 5-fluorouracil (5 FU), which kills the infected cancer cell and neighboring 5-FU sensitive tumor cells. Glioma cells and myeloid derived suppressor cells in the tumor are known to be sensitive to 5-FU. In animal models, the production of 5-FU locally kills dividing tumor cells during 5-FC cycles, which leads to durable and selective anticancer immune responses.. Data from ongoing clinical trials show encouraging evidence for increased survival compared to historical benchmarks, excellent safety, and evidence to support the proposed mechanism of action.

About Tocagen
Tocagen is a clinical-stage biopharmaceutical company pursuing the discovery, development and commercialization of gene therapy products using a broadly applicable, cancer-selective immuno-oncology platform. These products leverage retroviral replicating vectors (RRVs) that selectively infect cancer cells creating a factory of RRV in the tumor, which can then infect other cancer cells. These therapies are designed to help patients fight their cancer by locally activating their immune system selectively and broadly against multiple tumor associated antigens through a combination of mechanisms resulting in a durable, systemic benefit. Tocagen’s lead program is entering late-stage clinical development for patients with recurrent high grade glioma (glioblastoma or anaplastic astrocytoma).

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 about Tocagen or Toca 511 please visit www.tocagen.com or www.clinicaltrials.gov using the identifier NCT01470794, NCT01156584, NCT01985256, or NCT02414165.