Oxford BioMedica and sanofi-aventis announced encouraging new data from two Phase II trials of TroVax in renal cancer. TroVax is Oxford BioMedica's lead cancer immunotherapy product, which is being developed in collaboration with sanofi-aventis.
The Phase II data were presented by the lead investigator from the Methodist Hospital in Houston, Texas, at the 43rd Annual Meeting of the American Society of Clinical Oncology (ASCO) on 3 June in Chicago, Illinois (Abstract #3069).
Fifty-three patients with progressive metastatic renal cell cancer (RCC) have been enrolled and 48 patients are currently evaluable in the Methodist Hospital's two non-randomised Phase II trials of TroVax. The trials are designed to evaluate TroVax either as a single agent, or in combination with either interleukin-2 or interferon-alpha 2B. The treatment regimen in the two trials comprises seven intramuscular injections of TroVax over 41 weeks. The patients had previously failed various anti-cancer treatments before entering the trials.
TroVax was well tolerated with no serious adverse events attributable to the treatment. TroVax induced anti-5T4 antibody responses in 91% of patients. In patients with clear cell RCC, which is the most common subtype of renal cancer and is the patient group for the Phase III TRIST study, 24 of 35 (68%) evaluable patients showed disease control. Two patients had complete responses, three had partial responses and 19 had stable disease for periods exceeding three months, including three patients that have been stable for more than 17 months. Preliminary analysis of clinical benefit shows a statistically significant relationship between reduction in tumour burden (biologic response) in patients with clear cell RCC and patients' anti-5T4 antibody responses (p = 0.028). This is particularly encouraging since it supports the rationale that the 5T4-specific immune response induced by TroVax has therapeutic benefit.
At ASCO, the conclusions presented from this updated analysis of safety, immunogenicity and clinical benefit parameters were as follows:
● TroVax® was well tolerated and immunogenic in the context of these cytokines and has promising anti-tumour activity
● A significant number of objective responses have been seen in this heterogeneous group of heavily pre-treated renal cancer patients. These responses appear to be durable and are notable in the clear cell population.
● A preliminary analysis indicates a trend between 5T4-specific immune responses induced by TroVax® and clinical benefit in clear cell patients.
● These studies provide further support for the ongoing randomised Phase III TRIST study in renal cancer.
Dr. Bob Amato of the Genitourinary Oncology Centre, the Methodist Hospital in Houston, USA, who is the Principal Investigator for these two Phase II trials of TroVax in renal cancer, said: "TroVax continues to give encouraging indications of benefit in this heavily pre-treated renal cancer population. Although these are small, non-randomised studies, there have been a significant number of responders in this patient population. The ongoing analysis supports the notion that TroVax may have activity in this indication and further justifies the ongoing Phase III study, TRIST."
Dr Mike McDonald, Oxford BioMedica's Chief Medical Officer, commented on the new data: "Oxford BioMedica continue to be encouraged by the clinical data from ongoing trials of TroVax. This updated analysis from the renal cancer trials at the Methodist Hospital supports our development strategy with sanofi-aventis, which includes the Phase III TRIST trial in renal cancer and a randomised registration trial in metastatic colorectal cancer, a tumour type frequently overexpressing the 5T4 antigen. Over 300 patients have been enrolled in trials of TroVax in various cancer types and stages of disease. The data suggest that the product was well tolerated, immunogenic and potentially clinically active in all settings evaluated."
Dr Marc Cluzel, Senior Vice President, Science and Medical Affairs of sanofi-aventis commented: "TroVax is a very exciting compound that complements sanofi aventis' oncology and sanofi pasteur's vaccine activities. We are very encouraged by these further positive data on TroVax and looking forward to developing it in collaboration with Oxford Biomedica".
TroVax is Oxford BioMedica's leading cancer immunotherapy product, which is being developed in collaboration with Sanofi-Aventis. It is designed specifically to stimulate an anticancer immune response and has potential application in most solid tumour types. TroVax targets the tumour antigen 5T4, which is broadly distributed throughout a wide range of solid tumours. The presence of 5T4 is correlated with poor prognosis. The product consists of a poxvirus (MVA) gene transfer system, which delivers the gene for 5T4 and stimulates a patient's body to produce an anti-5T4 immune response. This immune response destroys tumour cells carrying the 5T4.
Oxford BioMedica is a biopharmaceutical company specialising in the development and commercialisation of novel therapeutic vaccines and gene-based therapies with a focus on oncology and neurotherapy.