• Six patients with subacute sclerosing panencephalitis were treated with the antiviral agent inosiplex. The clinical condition of four children continued to deteriorate in spite of the treatment, the condition of one remained unchanged, and that of another improved minimally. The effect of inosiplex in these patients is not evident since this group demonstrated a pattern of progression similar to that seen in subacute sclerosing panencephalitis without specific treatment.