— Immune Response Surrogate Algorithm Shown to be a Significant Predictor of Clinical Benefit —
Oxford, UK – 15 March 2011: Oxford BioMedica plc (“Oxford BioMedica” or “the Company”) (LSE: OXB), a leading gene therapy company, today announces that further analyses of the TroVax® Renal Immunotherapy Survival Trial (“TRIST”), a randomised, double-blind, placebo-controlled Phase III study, have been accepted for publication in Cancer Immunology, Immunotherapy, the official journal of the Association for Cancer Immunotherapy.
The online publication of the article, entitled “MVA–5T4-induced immune responses are an early marker of efficacy in renal cancer patients”, can be accessed at: www.springerlink.com/content/b54126121tm63152. TroVax® (MVA-5T4) is a therapeutic cancer vaccine designed to stimulate the immune system to destroy cancerous cells expressing the 5T4 tumour antigen which is broadly distributed throughout a wide range of solid tumours.
The Phase III TRIST results, published in Clinical Cancer Research in November 2010, confirmed the association between a high 5T4 antibody response and enhanced survival in patients treated with TroVax®. Using data from the TRIST study, Oxford BioMedica identified an algorithm (the “Immune Response Surrogate”; IRS) for predicting the quantitative 5T4 antibody response induced by TroVax® in order to identify those patients who are most likely to mount a strong 5T4 antibody response before receiving TroVax®. The IRS is a combination of three baseline (pre-treatment) blood parameters which can be measured using a blood test; 5T4 antibody levels, haemoglobin and haematocrit (the proportion of blood volume occupied by red blood cells).
When applied to the TRIST results, the IRS showed a significant correlation between the 5T4 antibody response, induced following vaccination with TroVax®, and treatment benefit, i.e. patients with higher IRS values who were treated with TroVax® survived longer than patients in the placebo group with the same IRS values. Importantly, the IRS was also associated with 5T4 antibody response and survival when applied to an independent dataset derived from the nine historic Phase I and II studies of TroVax® in patients with renal, colorectal and prostate cancer, implying that the IRS could potentially be applied to multiple cancer types.
The IRS will be used in all future TroVax® clinical trials including the current Phase II study in hormone refractory prostate cancer, in addition to the planned sponsored Phase II studies in mesothelioma, colorectal and ovarian cancers expected to start in 2011. Based on the typical blood profiles of patients with these cancer indications, it is expected that the IRS will predict that the majority of these patient populations may benefit from TroVax®.
Stuart Naylor, Chief Scientific Officer of Oxford BioMedica, said: “Few immunotherapy treatments have demonstrated a direct link between the predicted mode of action and clinical benefit. TroVax® stands apart as a cancer vaccine that elicits a strong and readily definable immune response. The IRS will allow us to target a more responsive patient population and we are confident that this novel biomarker will be further validated by results from our current Phase II clinical development programme for TroVax®.”