The present invention relates to a poxvirus comprising a defective F4L and/or I4L gene, to composition comprising such poxvirus and to the methods and use of such compositions and poxviruses for therapeutic purposes, and more particularly for the treatment of cancer.

The present invention provides an oncolytic virus comprising nucleotide sequence(s) encoding one or more immune checkpoint modulator(s). It also concerns a pharmaceutical composition comprising effective amount of said oncolytic virus and, eventually, a pharmaceutically acceptable vehicle and its use for treating proliferative diseases such as cancers.