Fingolimod in multiple sclerosis: profile of use in habitual practice

Safety and Efficacy of Fingolimod and Ocrelizumab in Pediatric Patients With Multiple Sclerosis

BACKGROUND

Fingolimod and ocrelizumab are approved treatments for adults with multiple sclerosis (MS); however, only fingolimod is approved by the Food and Drug Administration for the treatment of pediatric MS. Currently, there are limited data for the safety and efficacy of ocrelizumab use in children.

METHODS

This retrospective cohort study included patients with relapsing-remitting MS who started either ocrelizumab or fingolimod before age 18 years. Neuroimaging, electrocardiogram, laboratory evaluation, relapse history, and side effects were recorded at baseline and every six months.

RESULTS

Thirty-six pediatric patients were included (fingolimod, n = 14; ocrelizumab, n = 22). Clinical relapses occurred in 14% of patients treated with fingolimod versus in none of the patients treated with ocrelizumab. Seventy-one percent of patients in the fingolimod group switched or discontinued therapy compared with 9% treated with ocrelizumab (P = 0.0001). From patients with greater than six months of treatment on the given therapy (fingolimod n = 10, ocrelizumab n = 17), 60% on fingolimod exhibited new/enlarged T2-hyperintense lesions on brain magnetic resonance imaging compared with 6% on ocrelizumab (P = 0.004). Of those treated with ocrelizumab, 10 of 22 (45%) had infusion reactions during their initial infusion. Reaction rates decreased to 20% with subsequent infusions.

CONCLUSIONS

Ocrelizumab is associated with fewer brain lesions, lower clinical relapse rates, and reduced discontinuation rates compared with fingolimod. Although both therapies have the potential for adverse effects, these are unlikely to prompt discontinuation of therapy in isolation. These findings highlight the benefits of ocrelizumab as a treatment option for children and youth living with MS.

Structural basis for receptor selectivity and inverse agonism in S1P5 receptors

The bioactive lysophospholipid sphingosine-1-phosphate (S1P) acts via five different subtypes of S1P receptors (S1PRs) - S1P1-5. S1P5 is predominantly expressed in nervous and immune systems, regulating the egress of natural killer cells from lymph nodes and playing a role in immune and neurodegenerative disorders, as well as carcinogenesis. Several S1PR therapeutic drugs have been developed to treat these diseases; however, they lack receptor subtype selectivity, which leads to side effects. In this article, we describe a 2.2 Å resolution room temperature crystal structure of the human S1P5 receptor in complex with a selective inverse agonist determined by serial femtosecond crystallography (SFX) at the Pohang Accelerator Laboratory X-Ray Free Electron Laser (PAL-XFEL) and analyze its structure-activity relationship data. The structure demonstrates a unique ligand-binding mode, involving an allosteric sub-pocket, which clarifies the receptor subtype selectivity and provides a template for structure-based drug design. Together with previously published S1PR structures in complex with antagonists and agonists, our structure with S1P5-inverse agonist sheds light on the activation mechanism and reveals structural determinants of the inverse agonism in the S1PR family.

Cannabinoid and endocannabinoid system: a promising therapeutic intervention for multiple sclerosis

Multiple sclerosis (MS) is a chronic and complex neurodegenerative disease, distinguished by the presence of lesions in the central nervous system (CNS) due to exacerbated immunological responses that inflict oligodendrocytes and the myelin sheath of axons. In recent years, studies have focused on targeted therapeutics for MS that emphasize the role of G protein-coupled receptors (GPCRs), specifically cannabinoids receptors. Clinical studies have suggested the therapeutic potential of cannabinoids derived from Cannabis sativa in relieving pain, tremors and spasticity. Cannabinoids also appear to prevent exaggerated immune responses in CNS due to compromised blood-brain barrier. Both, endocannabinoid system (ECS) modulators and cannabinoid ligands actively promote oligodendrocyte survival by regulating signaling, migration and myelination of nerve cells. The cannabinoid receptors 1 (CB1) and 2 (CB2) of ECS are the main ones in focus for therapeutic intervention of MS. Various CB1/CB2 receptors agonists have been experimentally studied which showed anti-inflammatory properties and are considered to be effective as potential therapeutics for MS. In this review, we focused on the exacerbated immune attack on nerve cells and the role of the cannabinoids and its interaction with the ECS in CNS during MS pathology.