Oxford BioMedica
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OXB-301 (TroVax®)

OXB-301 (TroVax®) is a therapeutic vaccine that stimulates the immune system to destroy cancerous cells expressing the 5T4 tumour antigen which is present on most solid tumours.

Phase I / II investigator led studies underway. Recruitment to the SKOPOS (mesothelioma) study has now been completed and the data are being analysed. Data publication in a peer-reviewed journal is planned for 2016.

OXB-301 (TroVax®) is a cancer vaccine that has completed 11 clinical trials in colorectal, renal and prostate cancer. It elicits a strong and readily definable immune response. Oxford BioMedica has identified a biomarker, using a simple blood test, which predicts both the magnitude of the induced 5T4 antibody response and treatment benefit. This enables us to identify those patients who are most likely to benefit from treatment with OXB-301 (TroVax®).

Our approach

Administration:

OXB-301 (TroVax®) is a therapeutic vaccine that stimulates the immune system to destroy cancerous cells expressing the 5T4 tumour antigen. The product comprises a modified vaccinia virus Ankara (MVA) vector, encoding the 5T4 antigen. Vaccinia viruses are commonly used as delivery systems for the development of antigen-specific vaccines. MVA is the vaccinia strain of choice because of its excellent safety profile and its effectiveness in stimulating an immune response against “self-antigens”, such as 5T4.

Biomarker:
Few immunotherapy treatments have demonstrated a direct link between the predicted mode of action and clinical benefit. OXB-301 (TroVax®) stands apart as a cancer vaccine that elicits a strong and readily definable immune response. Oxford BioMedica has identified a biomarker, using a simple blood test, which predicts both the magnitude of the induced 5T4 antibody response and treatment benefit. This enables us to identify those patients who are most likely to benefit from treatment with TroVax®.

Clinical status

OXB-301 is a cancer vaccine currently undergoing four investigator sponsored Phase I/II and Phase II clinical trials in mesothelioma, inoperable metastatic colorectal cancer, ovarian cancer and early prostate cancer. The patients are selected using a biomarker, and the product utilises a 5T4 tumour associated antigen-encoding gene delivered by a poxvirus vector to stimulate the immune system to destroy cancerous cells expressing the antigen. In May 2015, investigators presented encouraging interim data from the colorectal cancer study at The Cancer Vaccine Institute's Second International Symposium on Immunotherapy. The mesothelioma study completed recruitment during 2015, and the data analysis is underway. Results from these two studies are expected during 2016.

Market opportunity

The oncology market is forecast to grow to $93 billion in 2015 (source: Datamonitor, 2011) and in particular, the cancer targeted therapies and immunotherapy market is forecast to increase to $36.8 billion by 2019 (source: Datamonitor, 2010). OXB-301 (TroVax®) is administered in the same way as most infectious disease vaccines are given; a simple injection in the arm. If shown to be efficacious in a pivotal trial for even just one of the major cancers where it is known that 5T4 is present on the tumours, OXB-301 (TroVax®) has significant potential.

Proof of concept

Results from 10 previous clinical trials in colorectal, renal and prostate cancer have shown that OXB-301 (TroVax®) is safe and well tolerated in over 500 patients; can be administered in combination with various other treatments and show clear indication of efficacy. Approximately 90 per cent of patients treated with OXB-301 (TroVax®) mounted an anti-cancer immune response to the 5T4 antigen.

Key publications:
Amato et al. Clin Cancer Res; 16(22) November 15, 2010: “Vaccination of Metastatic Renal Cancer Patients with MVA-5T4: A Randomized, Double-Blind, Placebo-Controlled Phase III Study”

Harrop et al. Cancer Immunol Immunother. 2012 Dec;61(12):2283-94: “Analysis of pre-treatment markers predictive of treatment benefit for the therapeutic cancer vaccine MVA-5T4 (TroVax)”

Vaccination of castration-resistant prostate cancer patients with TroVax (MVA-5T4) in combination with docetaxel: a randomized phase II trial.

Harrop R, Chu F, Gabrail N, Srinivas S, Blount D, Ferrari A.
Cancer Immunol Immunother. 2013 Sep;62(9):1511-20. doi: 10.1007/s00262-013-1457-z. Epub 2013 Jul 23.

Scurr et al. Cardiff University / Cancer Research Wales. "Both TroVax® and Cyclophosphamide induce anti-tumour immune responses that correlate with prolonged survival of end-stage colerectal cancer patients."

Clinical trials

If you would like to find out more information about the status of the trials, please visit the clinicaltrials.gov website.

Facts

$36.8 billion

The cancer targeted therapies and immunotherapy market is set to increase to $36.8 billion in 2019 (source: Datamonitor, 2010)


3,500

TroVax® has been tested in over 500 patients, who have collectively received over 3,500 doses, and has been shown to be safe and extremely well-tolerated