Advaxis's Cancer Immunotherapy Delays Progression of HER2+ Canine Osteosarcoma

Advaxis, Inc.

, a clinical-stage biotechnology company developing cancer immunotherapies, today announced that results from an ongoing clinical study of ADXS-HER2 in canine osteosarcoma (OSA), were presented by principal investigator Nicola J. Mason, B.Vet.Med., Ph.D., DACVIM, Associate Professor of Medicine at the University of Pennsylvania School of Veterinary Medicine, at the 2015 American College of Veterinary Internal Medicine (ACVIM) Forum in Indianapolis, Ind., on June 6, 2015. The preliminary data presented at ACVIM demonstrate that ADXS-HER2, in combination with palliative radiation, delayed tumor progression and prolonged overall survival in a group of 12 pet dogs with treatment naïve spontaneous OSA. Repeat doses of ADXS-HER2 were well tolerated with no systemic or cardiac toxicity. Of the 12 canine patients recruited to date, seven are alive with current survival times ranging from 66 to 479 days. The median survival time of dogs receiving palliative radiation plus ADXS-HER2 has not been reached. The median time to progression of these 12 canine patients is 238 days. The reported median survival time for historical control dogs with OSA that do not undergo amputation but instead receive the same palliative radiation protocol without ADXS-HER2 is 136 days. Preliminary results from the pilot study were recently presented by Dr. Mason at the 2015 American Association for Cancer Research (AACR) Annual Meeting on April 20, 2015, at which point the study comprised a group of 10 canine patients. "It is encouraging to see that ADXS-HER2 may have success as a cancer immunotherapy to treat dogs especially as it is associated with very few side effects," said Dr. Mason. "These results add to the growing body of data demonstrating the promising activity of ADXS-HER2." Data from the first Phase 1 clinical trial in canine OSA were presented last year during the 2014 ACVIM Forum, which showed ADXS-HER2 is able to delay or prevent metastatic disease and significantly prolong overall survival in canines with OSA that had minimal residual disease following standard of care (amputation and follow-up chemotherapy). At the time of the presentation, two-thirds of the treated canine patients were still alive and therefore a median survival time had not been reached. Conversely, historical control dogs that underwent standard of care and did not receive ADXS-HER2 had a median survival time of 316 days. Advaxis licensed ADXS-HER2 to Aratana Therapeutics

in March of 2014 for pet health indications and it is now being developed and prepared for commercialization using the name AT-014. Advaxis and Aratana anticipate conditional licensure of AT-014 for the treatment of canine OSA from the U.S. Department of Agriculture (USDA) in 2016. Dr. Mason's June 6, 2015 presentation at ACVIM is available on the Advaxis website at www.advaxis.com under the scientific presentations. Translating Canine Clinical Research into Human Trials The canine evidence with ADXS-HER2 may have important translational relevance for human patients with OSA and other HER2+ cancers, such as breast, gastric and esophageal. Advaxis expects to initiate a Phase 1b dose-escalation study of ADXS-HER2 in humans with HER2+ solid tumors in mid-2015. Once dosing is established in the human trial, Advaxis plans to work with Children's Oncology Group (COG) to launch a pivotal trial in human pediatric OSA in early 2016. The COG, a National Cancer Institute supported clinical trials group, is the world's largest organization devoted exclusively to childhood and adolescent cancer research. HER2 is expressed in approximately 40-60 percent of pediatric and canine OSA and in pulmonary metastatic disease, suggesting that immune targeting of HER2 might delay or eliminate metastatic disease. The hypothesis warrants investigation and will be tested in the pivotal pediatric OSA trial. HER2 expression is associated with more aggressive disease, increased risk of relapse and decreased overall survival. "Advaxis plans to translate this science into human patients, particularly in children with osteosarcoma," said Daniel J. O'Connor, President and Chief Executive Officer of Advaxis. "These data also demonstrate that our Lm Technology™ may offer an opportunity to address HER2+ tumors in pets. We look forward to Aratana building upon these findings to further develop and seek regulatory approval for additional Lm Technology™ antigen-targeted constructs for use in veterinary medicine."