Fingolimod as an effective therapeutic strategy for pediatric relapsing-remitting multiple sclerosis: two case reports

Fingolimod-related atrioventricular block in paediatric age group with multiple sclerosis: two case reports

Multiple sclerosis is a chronic inflammatory and demyelinating disease of the central nervous system, usually seen in young adults. Early onset of multiple sclerosis at age younger than 18 years is called paediatric multiple sclerosis. Unlike adult multiple sclerosis, paediatric multiple sclerosis causes morbidity at earlier ages and often progresses in a relapsing-remitting form. Although fingolimod is an effective drug used as a disease-modifiying therapy agent in relapsing-remitting paediatric multiple sclerosis patients, it can cause dysryhthmia in the early period after first dose. Our first case is a 14-year-old girl with relapsing-remitting paediatric multiple sclerosis patients who was started to take fingolimod treatment. In the fifth hour of the follow-up, asymptomatic bradycardia was seen and the electrocardiogram was consistent with first-degree atrioventricular block. Her rhythm got spontaneously normal after 12 hours. Second case was 13 years old girl. Steroid treatment was started after her first paediatric multiple sclerosis attack. Despite treatment, she had a second attack 2 weeks after the first attack. Therefore, the neurologist switched to fingolimod therapy. Second-degree atrioventriculer block developed after 4 hours from the initiation of therapy. After 8 hours, rhythm regressed to first-degree atrioventricular block then returned to normal up to 13th hours of follow up. The aim of this article is to draw attention to dysrhythmia side effect of fingolimod which can be fatal. Therefore, the clinician must take precautions. Close cardiac rhythm monitoring is mandatory after the initiation fingolimod theraphy.

Narrative review based on fingolimod therapy in pediatric MS

The course of pediatric-onset multiple sclerosis and adult multiple sclerosis shows some clinical differences. The rate of having a second attack after the first clinical event is 80% in children and around 45% in adults but the time to the second event is similar in all age groups. The pediatric group usually has a more aggressive onset than adults. On the other hand, a higher rate of complete recovery is observed in pediatric-onset multiple sclerosis after the first clinical event compared to the adult group. Despite a highly active initial disease course, pediatric-onset multiple sclerosis patients show a slower increase in disability than patients with adult-onset disease. This is thought to be due to greater remyelination capacity and plasticity of the developing brain. The management of pediatric-onset multiple sclerosis includes safety issues as well as effective disease control. In the pediatric-onset multiple sclerosis group, similar to adult multiple sclerosis, injectable treatments have been used for many years with reasonable efficacy and safety. Since 2011, oral treatments and then infusion treatments have been approved and used effectively in adult multiple sclerosis and have gradually entered clinical use in the pediatric-onset multiple sclerosis group. However, clinical trials are fewer, smaller, and include shorter follow-up due to the much lower prevalence of pediatric-onset multiple sclerosis than adult multiple sclerosis. This is particularly important in the era of recent disease-modifying treatments. This review of the literature presents existing data on the safety and efficacy of fingolimod, pointing to a relatively favorable profile.

Fingolimod as a first- or second-line treatment in a mini-series of young Hellenic patients with adolescent-onset multiple sclerosis: focus on immunological data

BACKGROUND

Pediatric onset multiple sclerosis(POMS) is characterized by a highly active profile, often warranting treatment with high efficacy disease-modulating therapies (DMTs). Fingolimod, an oral sphingosine-1-phosphate receptor modulator, is the first Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved DMT for the treatment of POMS.

OBJECT

Our aim is to present real-world data of seven fingolimod-treated POMS-patients, recruited in a single MS center in Greece.

METHODS

Clinical and imaging/laboratory data from 7 Hellenic patients fulfilling the International Pediatric Multiple Sclerosis Study Group (IPMSSG) criteria for POMS diagnosis, who have received fingolimod treatment, were selected. Human leukocyte antigen (HLA) genotyping was performed with standard low-resolution sequence-specific oligonucleotide techniques.

RESULTS

Three patients were treatment-naïve adolescents who received fingolimod as first-line treatment. Two experienced ongoing clinical and radiological disease activity and have been switched to natalizumab. The remaining cases were post-adolescent adults with POMS, where the vast majority experienced total/near-total disease remission. Fingolimod was generally well-tolerated. Two patients with high disease activity carried the HLA-DRB1*03 allele, while five patients were carriers of at least one of the HLA-DRB1*04, HLA-DRB1*13, and HLA-DRB1*14 alleles, which when not combined with HLA-DRB1*03 showed a trend towards a more favorable clinical course. Fingolimod responders showed a trend towards increased CD(16-56)⁺NK cell counts in immunophenotyping assays.

CONCLUSIONS

Our preliminary results support that response of POMS patients to fingolimod may be partially dependent on age and previous DMT, with younger and treatment-naïve patients presenting worse outcomes. The role of immunogenetics and immunophenotyping in personalized treatment warrants investigation in larger and more diverse populations.