The present application relates generally to genetically modified arenaviruses that are suitable for treating solid tumors, for example, via intratumoral administration. The arenaviruses described herein may be suitable for vaccines and/or treatment of solid tumors and/or for the use in immunotherapies. In particular, provided herein are methods and compositions for treating a solid tumor by administering a first arenavirus alone or in combination with another agent, including a second arenavirus, wherein the first and/or second arenavirus has been engineered to include a nucleotide sequence encoding a tumor antigen, tumor associated antigen or antigenic fragment thereof.
