Abstract: An oncolytic virus (for example a replication competent virus) comprising a transgene cassette encoding an anti-CD40 antibody or binding fragment thereof, wherein the transgene cassette comprises an amino acid sequence given in SEQ ID NO: 12 or a sequence at least 95% identical thereto (such as 96, 97, 98 or 99% identical thereto), in particular a cassette of SEQ ID NO: 12; pharmaceutical compositions comprising the same, methods of preparing said oncolytic virus and compositions and use of the oncolytic virus or composition in treatment, in particular in the treatment of cancer. Also provided is the treatment of a patient population characterised as having a cancer expressing CD40, in particular a cancer over expressing CD40, with a therapy according to the present disclosure.