Cancers are the most serious cause of morbidity and
mortality in humans and companion animals. The suffering
of humans and animals from malignant tumours of diverse
types and origins is just as traumatic as painful to
INTERVET, a dedicated veterinary pharmaceutical
company, proposes a project designed to develop anti-cancer
vaccines for dogs and cats. The project will be
implemented in collaboration with OXFORD BIOMEDICA, a
biotechnological company in Oxford which intends to develop
an immunotherapy for human use.
The proposed programme pulls together the technological
know-how and intellectual properties of both partners in an
anticancer approach that combines a promising tumour-
associated antigen (TAA) with a state-of-the-art vector
technology. In this approach, mouse, canine and feline
genes encoding the TAA (OBA1 Ag) will be cloned into and
expressed from the vector, MVA (modified vaccinia Ankara
virus). Immunization of the animals with the live,
recombinant vaccine is expected to elicit immune responses
appropriate for suppressing and/or controlling the
multiplication of neoplastic cells. Indeed, several model
experiments using various antigens have provided the proof
of principle for such an approach.
OBA1 is an oncofoetal antigen, almost ubiquitously expressed
on the surface of neoplastic cells. In human colorectal
cancers, the level of OBA1 Ag expression was shown to be
associated with the prognosis of malignancy. MVA is one of
the most versatile viral vectors available today. As a
replication-defective virus, the MVA possesses a number of
outstanding features as a vaccine vector. It has a proven
track record of safety and has been used in the successful
eradication of smallpox throughout the world.
The primary aim of the project is to develop MVA-based
vaccines for cancer immunotherapy. The same vaccines may
also prove to be efficacious as prophylactic vaccines.
Keywords: cancer, vaccines, immunotherapy.