A method of eliminating the risk of JCV activation in a subject undergoing immunosuppressive therapy, by administering an effective amount of a gene editing composition directed toward at least one target sequence in the JCV genome, cleaving the target sequence in the JCV genome, disrupting the JCV genome, eliminating the JCV infection, eliminating the risk of JCV activation, and treating the subject with an immunosuppressive therapy. A pharmaceutical composition including at least one isolated nucleic acid sequence encoding a CRISPR-associated endonuclease and at least one gRNA having a spacer sequence complementary to a target sequence in a JCV DNA, the isolated nucleic acid sequences being included in at least one expression vector. Pharmaceutical compositions including at least one isolated nucleic acid sequence encoding at least one TALEN, at least one ZFN, and gene editing composition of C2c1, C2c3, TevCas9, Archaea Cas9, CasY.1-CasY.6, CasX, or argonaute protein, which target at least one nucleotide sequence of the JCV genome.