Tocagen Presents Positive Preclinical, Proof-of-Mechanism Data at the American Association for Cancer Research (AACR) Annual Meeting

Combining Toca 511 and 5-FC with Checkpoint Inhibitors Reduces Tumor Burden in Preclinical Model

Toca 511 and 5-FC Increased Survival in Preclinical Metastatic Colorectal Cancer Model

NEW ORLEANS – April 19, 2016 – Tocagen Inc., a clinical-stage, cancer-selective gene therapy company, today announced positive preclinical, proof-of-mechanism data involving Toca 511 and 5-fluorocytosine (5-FC) were presented at the American Association for Cancer Research (AACR) Annual Meeting in New Orleans. The data demonstrate the potential for this investigational therapy to be used in combination with checkpoint inhibitors, specifically anti-PD-1 or anti-CTLA-4 antibodies, and as a potential treatment for metastatic colorectal cancer.

Highlights of results from the poster presentations are below. More information about the presentations, including abstract number and title, can be found on Tocagen’s website.

Combining Toca 511 and 5-FC with Checkpoint Inhibitors Reduces Tumor Burden in Preclinical Model

  • Combining Toca 511 and 5-FC with anti-PD-1 or anti-CTLA-4 blocking antibodies significantly reduced tumor growth, compared to checkpoint inhibitor treatments alone, in a subcutaneous glioma model
  • Treatment with Toca 511 and 5-FC increased the total number of tumor-infiltrating lymphocytes in the tumor microenvironment, including significant increases in T cell populations
  • The combination of Toca 511 and 5-FC with either checkpoint inhibitor significantly reduced tumor-associated myeloid-derived suppressor cells (MDSCs) and macrophages (TAMs)

Toca 511 and 5-FC Increased Survival in Preclinical Metastatic Colorectal Cancer Model

  • Increased survival and anti-tumor immune responses were observed following intravenous delivery of Toca 511 followed by courses of 5-FC in a syngeneic model of metastatic colorectal cancer
  • Confirming previously reported results, transgene expression was observed in tumor but not adjacent normal tissue
  • Treatment with Toca 511 and 5-FC significantly reduced MDSCs in tumor and spleen
  • Anti-tumor immune memory induced by Toca 511 and 5-FC was confirmed with complete rejection of tumor upon re-challenge
  • Based on these results, an investigational Phase 1b clinical trial evaluating Toca 511 & Toca FC (extended-release 5-FC) in patients with metastatic colorectal cancer is planned. More information about the clinical trial can be found by searching clinicaltrials.gov using the clinical trial identifier NCT02576665.

About Tocagen
Tocagen is a clinical-stage, cancer-selective gene therapy company focused on developing first-in-class, broadly applicable product candidates designed to activate a patient’s immune system against their own cancer from within. 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 www.tocagen.com/toca5. In 2016, Tocagen plans to initiate clinical trials of Toca 511 & Toca FC in patients with newly diagnosed HGG and other solid tumors. Tocagen obtained Fast Track designation from the U.S. Food and Drug Administration, for Toca 511 & Toca FC for the treatment of recurrent HGG and Orphan drug designation for the treatment of glioblastoma (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 www.tocagen.com or follow @Tocagen.