This disclosure provides reagent to treat tumor and cancer, and methods of using the same for treating tumor and cancer. One type of the reagent is pro-antibody, which is antibody that can be activated in tumor. Another type of the reagent is a conjugate of sialidase with affinity ligand that can bind to immuno cell surface or a conjugate of sialidase with affinity ligand that can bind to another antibody, therefore provide a sialidase based cancer immuno therapy strategy.
