SAN DIEGO, Nov. 26, 2013 /PRNewswire/ -- Tocagen Inc. today announced that interim clinical data from two ongoing Phase I investigational studies presented at the Society for Neuro-Oncology (SNO) Annual Meeting in San Francisco showed that Toca 511 administration followed by courses of oral Toca FC was safe and well tolerated in 60 patients treated to date with recurrent high grade glioma (HGG). HGG includes glioblastoma multiforme (GBM), the most common and aggressive form of primary brain cancer. In addition, data were presented showing that in tumor samples taken from some patients following treatment, Toca 511 selectively infected tumor cells and expressed a cytosine deaminase (CD) transgene. Tumor necrosis (cell death) was also observed by microscopic examination.
In addition to safety and tolerability data, Timothy Cloughesy, M.D., director of the Neuro-Oncology Program at the University California, Los Angeles Jonsson Cancer Center and a principal investigator for the Toca 511 and Toca FC studies also presented evidence of antitumor activity and symptomatic improvement in some patients.
Toca 511 is a retroviral replicating vector that carries a gene for an enzyme that converts orally delivered Toca FC (extended-release 5-FC) into 5-FU, a potent anti-cancer agent. More information about the trials can be found at ClinicalTrials.gov using the identifiers NCT01470794 and NCT01156584.
In addition, posters were presented at the conference on Toca 511 and 5-FC in combination with temozolomide (TMZ) or radiation in preclinical glioma models, which showed significantly prolonged survival compared to control groups. Since radiation therapy and temozolomide are part of standard therapy for patients with newly diagnosed GBM, these data provide support for clinical investigation of Toca 511 and Toca FC in first line therapy.
"I am pleased with the progress we have made with our clinical programs, and the available survival data provide optimism for subsequent dose groups in these studies," said Harry Gruber, M.D., CEO of Tocagen. "The results from our ongoing clinical studies, taken together with the depth of our preclinical research, provide momentum for the continued investigation of this novel gene therapy for patients with brain cancer."
Data from preclinical brain cancer studies also presented at the conference demonstrate the feasibility of intravenous administration of Toca 511 as a potential complement to the current intra-tumoral delivery methods. An investigational trial was recently initiated to evaluate intravenous delivery of Toca 511 in combination with courses of oral Toca FC in patients with recurrent HGG (NCT01985256). In the future, Toca 511 may be investigated for the treatment of additional types of cancers beyond brain cancer, including metastatic cancers.
About Toca 511 and Toca FC
The combination of Toca 511 (vocimagene amiretrorepvec) for injection and Toca FC (flucytosine) extended-release tablets, is being investigated in Phase I studies at leading centers across the United States in patients with recurrent high grade glioma, including glioblastoma multiforme (GBM). Toca 511 is a retroviral replicating vector (RRV) that is designed to deliver a prodrug activator gene called cytosine deaminase (CD) selectively to cancer cells. After allowing time for Toca 511 to spread through the tumor, those cancer cells expressing the CD gene can convert the antibiotic drug flucytosine into the anti-cancer drug 5-fluorouracil (5-FU). By producing 5-FU locally with CD, this technology has the potential to produce much higher intratumoral concentrations of 5-FU than can be currently attained with systemic administration. In these studies, patients receive a single administration of Toca 511 at the time of surgical removal of the brain tumor or by transcranial injection into the tumor followed by repeat cycles of oral Toca FC. A study in patients with brain cancer has recently been initiated to evaluate intravenous administration of Toca 511 followed by oral Toca FC.
Tocagen Inc. is a privately funded, clinical stage biopharmaceutical company pursuing the discovery, development and commercialization of gene therapy products for the treatment of cancer. Tocagen is initially focusing on treatments for patients with advanced cancer for whom no adequate treatments currently exist. Toca 511 and Toca FC, the company's lead investigational combination product, is being evaluated in three clinical trials in patients with recurrent high grade glioma, including glioblastoma multiforme (GBM). 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.
SOURCE Tocagen Inc.