The present invention relates to a pharmaceutical composition containing a PEGylated IGF-I variant derived from the wild-type human IGF-I amino acid sequence where one or two of the lysine amino acids at positions 27, 65, and 68 are altered to be a polar amino acid other than lysine and where the PEG is attached to at least one lysine residue. The invention also relates to methods for the treatment, prevention and/or delay of progression of neuromuscular disorders, in particular amyotrophic lateral sclerosis (ALS) by administering a therapeutically effective amount of the pharmaceutical composition of the invention.
