This retrospective study reviewed the hospital files of a subset of 7 patients with Duchenne muscular dystrophy (DMD) participating in the open-label phase I/II PRO051-02 study in Leuven: the authors aimed to describe the injection site reactions in these children treated with drisapersen (PRO-051), a 2′-O-methyl phosphorothioate RNA antisense oligonucleotide, that induces exon 51 skipping in DMD. Erythema followed by hyperpigmentation, fibrosis, and calcification were seen at the injection sites in all children. Ulcerations, which were difficult to heal, occurred in 5 of 7 children. Progression still occurred after switching to intravenous administration of drisapersen or even after stopping therapy. Systemic reactions included a reversible proteinuria and α1-microglobulinuria. Moreover, hypotrichosis was a common feature.
