Siponimod for multiple sclerosis

Frequency of pharmacogenomic variants affecting safety and efficacy of immunomodulators and biologics in a South Asian population from Sri Lanka

BACKGROUND

Immunomodulators are important for management of autoimmune diseases and hematological malignancies. Significant inter-individual variation in drug response/reactions exists due to genetic polymorphisms. We describe frequency of identified genetic polymorphisms among Sri Lankans.

METHODS

Sri Lankan data were obtained from an anonymized database of 670 participants. Data on variants and global distribution of Minor Allele frequency (MAF) of other populations (South Asian, Ashkenazi-Jewish, East-Asian, European-Finnish, European-non-Finnish, Latino-American, African/African-American) were obtained from pharmGKB online database.

RESULTS

SLC19A1 (rs1051266) variant had a MAF (95% CI) of 63.3% (60.7-65.9). Other common variants included FCGR3A (rs396991), MTHFR (rs1801133), ITPA (rs1127354), CYP2C9*3 (rs1057910) and NUD15*3 (rs116855232), with MAFs of 35.3% (32.7-37.9), 12.2% (10.4-13.9), 10.9% (9.2-12.6), 9.8% (8.2-11.4), 8.3% (6.8-9.8) respectively. Less commonly present variants included CYP2C9*2 (rs1799853) (2.5%[1.7-3.4]), TPMT*3C (rs1142345) (1.9%[1.1-2.6]), TPMT*3B (rs1800460) (0.2%[0-0.5]), CYP3A5*6 (rs10264272) (0.2%[0-0.4]) and CYP3A4*18 (rs28371759) (0.1%[0-0.2]). The SLC19A1 (rs1051266), NUD15*3 (rs116855232), CYP2C9*3 (rs1057910), FCGR3A (rs396991), and ITPA (rs1127354) showed significantly higher frequencies in Sri Lankans compared to many other populations, exceptions include FCGR3A in Ashkenazi-Jewish and ITPA in East-Asians. Conversely, MTHFR (rs1801133), TPMT*3B (rs1800460), and CYP2C9*2 (rs1799853) were significantly less prevalent among Sri Lankans than in  many other populations. Sri Lankans exhibited lower prevalence of TPMT*3C (rs1142345) compared to European-non-Finnish, Latino-Americans, and African/African-Americans; CYP3A4*18 (rs28371759) compared to East-Asians; and CYP3A5*6 (rs10264272) compared to African/African-Americans and Latino-Americans.

CONCLUSION

Sri Lankans exhibit higher frequencies in variants reducing methotrexate efficacy (SLC19A1), increasing azathioprine myelotoxicity (NUDT15), and lower frequencies in variants linked to increased azathioprine toxicity (TPMT*3B, TPMT*3C), reduced tacrolimus efficacy (CYP3A4*18), and methotrexate toxicity risk (MTHFR). Beneficial variants enhancing rituximab efficacy (FCGR3A) are more prevalent, while those reducing tacrolimus dosage (CYP3A5*6) are less common. This highlights need for targeted medication strategies to improve treatment outcomes.

The Benefits and Risks of Switching from Fingolimod to Siponimod for the Treatment of Relapsing-Remitting and Secondary Progressive Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neurodegenerative disease that affects the central nervous system (CNS). Currently, MS treatment is limited to several Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved medications that slow disease progression by immunomodulatory action. Fingolimod and siponimod have similar mechanisms of action, and consequently, their therapeutic effects may be comparable. However, while fingolimod is mainly used for relapsing-remitting MS (RRMS), siponimod, according to EMA label, is recommended for active secondary progressive MS (SPMS). Clinicians and scientists are analysing whether patients can switch from fingolimod to siponimod and identifying the advantages or disadvantages of such a switch from a therapeutic point of view. In this review, we aim to discuss the therapeutic effects of these two drugs and the advantages/disadvantages of switching treatment from fingolimod to siponimod in patients with the most common forms of MS, RRMS and SPMS.

First in vivo fluorine-19 magnetic resonance imaging of the multiple sclerosis drug siponimod

Theranostic imaging methods could greatly enhance our understanding of the distribution of CNS-acting drugs in individual patients. Fluorine-19 magnetic resonance imaging (¹⁹F MRI) offers the opportunity to localize and quantify fluorinated drugs non-invasively, without modifications and without the application of ionizing or other harmful radiation. Here we investigated siponimod, a sphingosine 1-phosphate (S₁P) receptor antagonist indicated for secondary progressive multiple sclerosis (SPMS), to determine the feasibility of in vivo ¹⁹F MR imaging of a disease modifying drug. Methods: The ¹⁹F MR properties of siponimod were characterized using spectroscopic techniques. Four MRI methods were investigated to determine which was the most sensitive for ¹⁹F MR imaging of siponimod under biological conditions. We subsequently administered siponimod orally to 6 mice and acquired ¹⁹F MR spectra and images in vivo directly after administration, and in ex vivo tissues. Results: The ¹⁹F transverse relaxation time of siponimod was 381 ms when dissolved in dimethyl sulfoxide, and substantially reduced to 5 ms when combined with serum, and to 20 ms in ex vivo liver tissue. Ultrashort echo time (UTE) imaging was determined to be the most sensitive MRI technique for imaging siponimod in a biological context and was used to map the drug in vivo in the stomach and liver. Ex vivo images in the liver and brain showed an inhomogeneous distribution of siponimod in both organs. In the brain, siponimod accumulated predominantly in the cerebrum but not the cerebellum. No secondary ¹⁹F signals were detected from metabolites. From a translational perspective, we found that acquisitions done on a 3.0 T clinical MR scanner were 2.75 times more sensitive than acquisitions performed on a preclinical 9.4 T MR setup when taking changes in brain size across species into consideration and using equivalent relative spatial resolution. Conclusion: Siponimod can be imaged non-invasively using ¹⁹F UTE MRI in the form administered to MS patients, without modification. This study lays the groundwork for more extensive preclinical and clinical investigations. With the necessary technical development, ¹⁹F MRI has the potential to become a powerful theranostic tool for studying the time-course and distribution of CNS-acting drugs within the brain, especially during pathology.

Prevalence of fatigue and its explicative variables among people with multiple sclerosis

BACKGROUND: Fatigue is the most prevalent symptom among people with multiple sclerosis (PwMS). Although exercise effectively reduces fatigue, the relationship between daily physical activity and fatigue has only recently been demonstrated. OBJECTIVE: The aim of this study was to evaluate the prevalence of fatigue and to understand the relationship with several variables in French PwMS. METHODS: Data were collected from 191 PwMS using Modified Fatigue Impact Scale (MFIS) and Fatigue Severity Scale (FSS) for fatigue, and the Godin Leisure-Time Exercise Questionnaire (GLTEQ) for physical activity. RESULTS: 110 PwMS (57%), 35 PwMS (18%) and 46 PwMS (24%) were considered as fatigued, non-fatigued and in the grey zone, respectively. Greater physical activity was observed in non-fatigued PwMS (20.2±19.8) compared to fatigued PwMS (12.5±14.1). FSS and MFIS scores were associated with physical activity (r = –0.28 and r = –0.25, respectively, p <  0.05). Using multivariate analysis, disability, physical activity and being unemployed explained 21% of the variance of the MFIS. CONCLUSIONS: The present study confirms that physical activity and fatigue are associated. Disability and unemployment status should also to be consider when assessing fatigue. Activity-oriented health policies should be redesigned to improve fatigue among PwMS.

Multiple Sclerosis: Therapeutic Strategies on the Horizon

Multiple sclerosis (MS) is a chronic disease affecting the brain and the spinal cord. It is a chronic inflammatory demyelinating disease of the central nervous system. It is the leading cause of non-traumatic disability in young adults. The clinical course of the disease is quite variable, ranging from stable chronic disease to rapidly evolving debilitating disease. The pathogenesis of MS is not fully understood. Still, there has been a rapid shift in understanding the immune pathology of MS away from pure T cell-mediated disease to B cells and microglia/astrocytes having a vital role in the pathogenesis of MS. This has helped in the emergence of new therapies for management. Effective treatment of MS requires a multidisciplinary approach to manage acute attacks, prevent relapses and disease progression and treat the disabling symptoms associated with the disease. In this review, we discuss the pathogenesis of MS, management of acute relapses, disease-modifying therapies in MS, new drugs and drugs currently in trial for MS and the symptomatic treatment of MS.  All language search was conducted on Google Scholar, PubMed, MEDLINE, and Embase till February 2022. The following search strings and medical subheadings (MeSH) were used: "Multiple Sclerosis", "Pathogenesis of MS", and "Disease-modifying therapies in MS". We explored literature on the pathogenic mechanisms behind MS, management of acute relapses, disease-modifying therapies in MS and symptomatic management.

Lymphocyte-Related Immunomodulatory Therapy with Siponimod (BAF-312) Improves Outcomes in Mice with Acute Intracerebral Hemorrhage

Modulators of the sphingosine-1-phosphate receptor (S1PR) have been proposed as a promising strategy for treating stroke. However, the detailed mechanisms and the potential translational value of S1PR modulators for intracerebral hemorrhage (ICH) therapy warrant exploration. Using collagenase VII-S-induced ICH in the left striatum of mice, we investigated the effects of siponimod on cellular and molecular immunoinflammatory responses in the hemorrhagic brain in the presence or absence of anti-CD3 monoclonal antibodies (Abs). We also assessed the severity of short- and long-term brain injury and evaluated the efficacy of siponimod in long-term neurologic function. Siponimod treatment significantly decreased brain lesion volume and brain water content on day 3 and the volume of the residual lesion and brain atrophy on day 28. It also inhibited neuronal degeneration on day 3 and improved long-term neurologic function. These protective effects may be associated with a reduction in the expression of lymphotactin (XCL1) and T-helper 1 (Th1)-type cytokines (interleukin 1β and interferon-γ). It may also be associated with inhibition of neutrophil and lymphocyte infiltration and alleviation of T lymphocyte activation in perihematomal tissues on day 3. However, siponimod did not affect the infiltration of natural killer cells (NK) or the activation of CD3-negative immunocytes in perihematomal tissues. Furthermore, it did not influence the activation or proliferation of microglia or astrocytes around the hematoma on day 3. Siponimod appears to have a profound impact on infiltration and activation of T lymphocytes after ICH. The effects of neutralized anti-CD3 Abs-induced T-lymphocyte tolerance on siponimod immunomodulation further confirmed that siponimod alleviated the cellular and molecular Th1 response in the hemorrhagic brain. This study provides preclinical evidence that encourages future investigation of immunomodulators, including siponimod, which target the lymphocyte-related immunoinflammatory reaction in ICH therapy.

Siponimod for multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system, with an unpredictable course. Current MS therapies such as disease-modifying therapies focus on treating exacerbations, preventing new exacerbations and avoiding the progression of disability. Siponimod (BAF312) is an oral treatment, a selective sphingosine-1-phosphate (S1P) receptor modulator, for the treatment of adults with relapsing forms of MS including active, secondary progressive MS with relapses.

OBJECTIVES

To assess the benefits and adverse effects of siponimod as monotherapy or combination therapy versus placebo or any active comparator for people diagnosed with MS.

SEARCH METHODS

On 18 June 2020, we searched the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Trials Register, which contains studies from CENTRAL, MEDLINE and Embase, and the trials registry databases ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP). We also handsearched relevant journals and screened the reference lists of published reviews and retrieved articles and searched reports (2004 to June 2020) from the MS societies in Europe and America.

SELECTION CRITERIA

We included randomised parallel controlled clinical trials (RCTs) that evaluated siponimod, as monotherapy or combination therapy, versus placebo or any active comparator in people with MS. There were no restrictions on dose or administration frequency.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We discussed disagreements and resolved them by consensus among the review authors. Our primary outcomes wereworsening  disability , relapse and adverse events, and secondary outcomes were annualised relapse rate, gadolinium-enhancing lesions, new lesions or enlarged pre-existing lesions and mean change of brain volume. We independently evaluated the certainty of evidence using the GRADE approach. We contacted principal investigators of included studies for additional data or confirmation of data.

MAIN RESULTS

Two studies (1948 participants) met our selection criteria, 608 controls and 1334 treated with siponimod. The included studies compared siponimod with placebo. Overall, all studies had a high risk of bias due to selective reporting and attrition bias.  Comparing siponimod administered at a dose of 2 mg to placebo, we found that siponimod may reduce the number of participants with disability progression at six months (56 fewer people per 1000; risk ratio (RR) 0.78, 95% confidence interval (CI) 0.65 to 0.94; 1 study, 1641 participants; low-certainty evidence) and annualised relapse rate (RR 0.43, 95% CI 0.34 to 0.56; 2 studies, 1739 participants; low-certainty evidence). But it might lead to little reduction in the number of participants with new relapse (166 fewer people per 1000; RR 0.38, 95% CI 0.15 to 1.00; 1 study, 94 participants; very low-certainty evidence). We observed no evidence of a difference   due to adverse events for siponimod at 2 mg compared to placebo (14 more people per 1000; RR 1.52, 95% CI 0.85 to 2.71; 2 studies, 1739 participants, low-certainty evidence). In addition, due to the high risk of inaccurate magnetic resonance imaging (MRI) data in the two included studies, we could not combine data for active lesions on MRI scans. Both studies had high attrition bias resulting from the unbalanced reasons for dropouts among groups and high risk of bias due to conflicts of interest. Siponimod may reduce the number of gadolinium-enhancing T1-weighted lesions at two years of follow-up (RR 0.14, 95% CI 0.10 to 0.19; P < 0.0001; 1 study, 1641 participants; very low-certainty evidence). There may be no evidence of a difference between groups in the number of participants with at least one serious adverse event excluding relapses (113 more people per 1000; RR 1.80, 95% CI 0.37 to 8.77; 2 studies, 1739 participants; low-certainty evidence) at six months. No data were available regarding cardiac adverse events. In terms of safety profile, the most common adverse events associated with siponimod were headache, back pain, bradycardia, dizziness, fatigue, influenza, urinary tract infection, lymphopenia, nausea, alanine amino transferase increase and upper respiratory tract infection. These adverse events have dose-related effects and rarely led to discontinuation of treatment.

AUTHORS' CONCLUSIONS

Based on the findings of the RCTs included in this review, we are uncertain whether siponimod interventions are beneficial for people with MS. There was low-certainty evidence to support that siponimod at a dose of 2 mg orally once daily as monotherapy compared with placebo may reduce the annualised relapse rate and the number of participants who experienced disability worsening, at 6 months. However, the certainty of the evidence to support the benefit in reducing the number of people with a relapse is very low.  The risk of withdrawals due to adverse events requires careful monitoring of participants over time. The duration of all studies was less than 24 months, so the efficacy and safety of siponimod over 24 months are still uncertain, and further exploration is needed in the future. There is no high-certainty data available to evaluate the benefit on MRI outcomes. We assessed the certainty of the body of evidence for all outcomes was low to very low, downgraded due to serious study limitations, imprecision and indirectness. We are uncertain whether siponimod is beneficial for people with MS. More new studies with robust methodology and longer follow-up are needed to evaluate the benefit of siponimod for the management of MS and to observe long-term adverse effects. Also, in addition to comparing with placebo, more new studies are needed to evaluate siponimod versus other therapeutic options.