Advances in Antiviral Therapy for Subacute Sclerosing Panencephalitis

Abstract

Subacute sclerosing panencephalitis (SSPE) is a late-onset, intractable, and fatal viral disease caused by persistent infection of the central nervous system by a mutant strain of the measles virus. Ribavirin intracerebroventricular therapy has already been administered to several SSPE patients in Japan based on fundamental and clinical research findings from our group, with positive therapeutic effects reported in some patients. However, the efficacy of this treatment approach has not been unequivocally established. Hence, development of more effective therapeutic methods using new antiviral agents is urgently needed. This review describes the current status of SSPE treatment and research, highlighting promising approaches to the development of more effective therapeutic methods.

Trends and Treatment of Sub-Acute Sclerosing Panencephalitis: An Updated Review

“…3 Isoprinosine is also known to prolong survival of patients suffering from SSPE, the 8-year survival rate wars 61% in patients who were given Isoprinosine as compared to only 8% in patients who were not administered Isoprinosine. 21 Within a trial not comprising of a concurrent placebo control group, 35% of subjects who were administered Isoprinosine were stabilized or their condition was substantially better at a much higher rate than a rate of only 5% to 10%. 27 Several studies that evaluated the use of Isoprinosine in curing SSPE and their results are mentioned in Table 2.…”

“… 28 However, a study has shown that the oral administration of Ribavirin does not affect SSPE patients, mainly because the concentration required to deliver a therapeutic effect were not reached within the CSF. 21 In a limited number of random trials a little beneficial effect is shown when used together with Thymic Humoral Factor, Amantadine, steroids, and plasmapheresis intraventricular IFN and anti-CD 20 antibodies. 24 CSF measles antibody titers in SSPE patients are lowered by Ribavirin, decreasing neurological symptoms without any adverse effects.…”

“…Intraventricular IFN and oral IP have not shown adverse effects, but long-term treatments carry the risk of upper and lower motor neuron toxicity developing, IFN α-induced encephalopathy and meningitis. 21 Oral Isoprinosine combined with Intrathecal IFN-α is the most common treatment for SSPE nowadays. 29 However, in a study where intrathecal IFN- in combination with Isoprinosine was administered and considered to be of benefit by most, however due to the presence of severe side effects to intrathecal administration was a huge downfall for this mode of treatment.…”

“…Favipiravir, an RNA-Polymerase inhibitor, could potentially be exploited for the treatment of SSPE in the future. 21 Interferon-Stimulating Genes (ISGs) and a variety of other therapy methods have ben tried to treat SSPE, but their efficacy has to be confirmed because it appears to be case-dependent. Table 4 shows results of various studies related to the future treatments of SSPE including fusion inhibitor peptides, RNA polymerase inhibitors, and Neutralizing antibody-derived molecules.…”

“…Results of Studies3,21,24,27 That Were Conducted to Evaluate the Effects of Isoprinosine on Patients Having SSPE.…”